Cadsoft Eagle is a comprehensive tool for development printed circuit boards , starting with the creation of a fundamental electrical diagram and ending with the creation of a printed circuit board and its routing. In addition, by downloading the program, you will receive a fairly large library containing many standard and fairly common electronic components.

One of the main advantages of this package professionals highlight the complete synchronicity of changes in the project. For example, if you change or delete any component on the circuit, this will immediately be reflected in the board drawing. In programs such as ACCEL EDA, P-CAD and OrCAD, it is necessary to constantly monitor the entire project, with the slightest changes and at any stage of work. In addition, in EAGLE, event rollback (UNDO) is possible for any number of actions (even the most powerful CAD today, ACCEL EDA, does not allow this to be done).

EAGLE allows you to design multilayer boards containing up to 16 layers and having dimensions up to 4000x4000 mm with a resolution of 0.0001 mm. The unit system (inch or metric) can be changed at any stage of the project without any loss.

The program includes:
Schematic Module - a module for creating schematic diagrams. It has a convenient interface, a grid for aligning components and electrical lines, and elements for drawing on a sheet.
Layout Editor - PCB editor. Allows you to place components on the future PCB, there is a check for errors, auxiliary lines to simplify the manual routing process, and tools for applying silk-screen markings to the PCB.
Autorouter - module for automatic routing of printed circuit boards. A large number of settings allows you to improve the quality of auto-routing.
Library Editor is very flexible and convenient editor libraries.

The standard delivery set also includes modules that check the correct connection of electrical circuits (ERC - Electrical Rule Check) and the correct arrangement of components on the board (DRC - Design Rule Check). And two latest transactions look much nicer than in more advanced systems. The program checks the correctness of the design and connections so that the user does not even know that some third-party utility is doing this. It should be noted that the user does not have to launch various software modules for this, as is done in P-CAD or ACCEL EDA - all transitions are carried out within the program itself. It is also possible to fill a given space with polygons.

Program information
Year of manufacture: 2016
Developer website: cadsoftusa.com
OS: Windows 7 / Windows 8 / 8.1 / 10
Interface language: Multilanguage / Russian
Medicine / Medical: present / is present (Portable - not required)
Size:121.6 MB
ZIP archive
Download: CadSoft Eagle 7.7.0 Ultimate + Portable (ML / RUS)

Sections: Technology

One of the most important tasks of modern education is the development of students’ creative skills and the formation of their creative thinking.

Great opportunities for the development of creative activity and creative abilities of schoolchildren are included in the program of the educational field "Technology". The development of cognitive activity of schoolchildren is facilitated by the “Technology” project method, which is widely used in the educational field, implying independent creative work of students, carried out under the guidance of a teacher. The teacher needs to develop such types of creative activity, the result of which can be work that is competitive at the All-Russian Olympiad for schoolchildren in technology, exhibitions and scientific and technical competitions.

This area of ​​project activity is work based on components of modern electronic equipment. One of the stages of work is the development and production of printed circuit boards.

The purpose of this work: to show students the possibilities modern systems designing printed circuit boards, try your hand and show your intellectual potential in creating new objects of creative activity.

Method of implementation: personally oriented training in preparation for the implementation of the technological profile of training.

Cadsoft EAGLE is a comprehensive tool for PCB design, from creating a circuit diagram to creating a printed circuit board and routing it. The program contains three modules: The program includes graphics editor schematic editor (Schematic Editor), printed circuit board editor (Layout Editor), a very flexible and convenient library editor (Library Editor) and autorouter (Autorouter). In addition, the program has a fairly large library containing many standard and fairly common electronic components, such as microcontrollers, so you will not need to draw an image of the component on the circuit yourself and create a footprint for the printed circuit board.

PCB development consists of several stages:

1. Creating an electrical wiring diagram
2. Image of the outline of the board (its shape and size)
3. Location of parts on the board
4. Making connections between the leads of parts (tracks)

Let's look at these steps.

Let's launch Eagle. Let's start with the main project window.

There's a tree structure there.

Libraries - component libraries. There's a lot here, but here's work environment We will include them selectively. A green dot next to the library name means it is included in the environment and is available in item search/selection. There is no need to manually turn off all points; just select Use None from the context menu, and then turn on the ones you need selectively.

The most common libraries:

74xx-eu.lbr	standard logic library.
atmel.lbr	AVR controllers
con-berg.lbr	USB connector.
crystal.lbr	all sorts of quartz
diode.lbr	diodes
docu-dummu.lbr	primitives of the main elements. Will be needed to create your own components
holes.lbr	standard holes for fasteners.
ic-package.lbr	Just some microcircuits in cases.
jumpers.lbr	Various jumpers.
microchip.lbr	PIC controllers
pinhead.lbr	Pin connectors.
rcl.lbr	All resistors, capacitors and inductors are here.

Entering a schema

The Schematic Editor is used to enter a schematic. Before you start working with the project, you need to clearly define which components and in which housings are needed for this.

Open Control Panel. Click File\New\Schematic. This will open a window with the future diagram.

We select components for our circuit using the ADD button. Having selected a component, click the left mouse button to place it on the work field (sheet). If desired, the component can be rotated clockwise 90 degrees with the right mouse button.
We arrange the components according to our desires using the MOVE button (the right button is also used here for rotation).

We connect the pins of the components using the WIRE button. The right mouse button is used in this case to select the bend angle of the connection line.
In order to give the circuit a complete look, we assign a name to each element (for example, R1, DD3, etc.). For this we use the NAME button. In most cases, the program assigns names automatically as components are installed on the workspace. Here it is necessary to pay attention to the inadmissibility of entering Russian characters and spaces. In addition to components, names can also be assigned to connections: this will come in handy later, when routing the board.

We arrange the values ​​- this mainly concerns passive elements: resistors, capacitors, coils. This is what the VALUE button is for.
That's it, the diagram is ready!

Now let's look at creating a circuit diagram and a printed circuit board using specific example. As an example, we use the circuit of an LED lamp, which was presented at the final stage of the first Moscow Festival of Scientific and Technical Creativity and Youth Initiatives.

The circuit consists of several LEDs and quenching resistors.

1) We decide on the necessary details and the libraries in which they are located. For this project we will need the following parts:

• 4 fixed resistors;
• 10 LEDs;
• 1 diode;
• 1 pair of pins for soldering wires;

We search the libraries for the selected components. Diode MBR0520LT - in the diode.lbr library. LED5MM LEDs are located in led.lbr, fixed resistors are in rcl.lbr, a pair of pins for soldering wires is called 22-23-2021 and is located in con-molex.lbr.

When selecting components, you should immediately select its Package, because when creating a printed circuit board from a schematic, its “packaging” is transferred automatically (this is especially true for microcircuits).

2) We carry out the first stage of the project configuration - select the grid with the GRID button (by default its value is set to 0.1 inches, the step is in inches, the image is in lines, and its visibility is turned off).

Possible options:

• The grid can be turned on/off;
• The grid can look like lines/dots;
• Project units: mils, millimeters, microns, inches;

The grid values ​​can be anything, however I recommend 0.05 inches for drawing patterns. It should be especially emphasized that only meshes that are multiples of 0.1 inches (0.05, 0.025, 0.0125, 0.00625) should be used in the entire project - otherwise difficulties may arise at any stage of the work. At first, I also recommend turning on all layers with the DISPLAY button, and at the same time setting the grid to 0.05 inches and making it visible.

3) By pressing the ADD button, we take out and place on the working field the above components from the above libraries. Approximately in this order:

4) All that remains is to correctly connect all the elements of the circuit. By clicking on Wire, we connect the pins of the components.

After completing the connections of the circuit, we get a picture similar to that shown in the figure. The circuit is ready, now you can start creating a drawing of the printed circuit board.

Creating a board from a schematic

Layout Editor is used to create a board

We have schematic diagram"lamp".

To start working with the board, you need to click the switch button from Schematic to Layout:

After clicking it, EAGLE tells us that there is no board that matches our circuit. And at the same time he offers to create it from the diagram. We answer “Yes” and get this window:

Using drawing commands we will draw the outlines of the board.

Now let's arrange the components so that the connections between the pins of the parts intersect with each other as little as possible.

And to complete the work, we will connect the leads of the parts to each other using connecting lines - the so-called tracks.

To do this, use the button:

This is what you get in the end: a finished board.

Literature.

1. Technology: Textbook for 9th grade students in general education institutions / edited by V.D. Simonenko.-M.: Ventana-Graf, 2005.-288 p.
2. Technology: Textbook for 10th grade students in general education institutions / edited by V.D. Simonenko.-M.: Ventana-Graf, 2006.-288 p.
3. Bogatyrev A.N. Electrical and radio engineering: Textbook. For 8-9 grades. educational institutions.-M.: Prsveshchenie, 1996. - 224 p.
4. Golubtsov M.S. AVR microcontrollers- from simple to complex. M.: SOLON, 2004

In the eagle's nest
90% of my PCB layout needs were met by Sprint Layout. I usually do it manually, without an initial diagram, and everything fits quite well in my head. But progress does not stand still and I have long been called a retrograde :) And I decided to crawl to another system. main reason— support for circuit diagrams and highlighting of connections in the circuit editor, which I sometimes really lacked in Sprint Layout. Before this, I tried several different ones and settled on Eagle cad.

Why Eagle?
I was guided in my choice the following parameters in order of importance:

• Editor with circuit diagram support and highlighting of connections.
• Ease of use in the tracer. Eagle has a number of specific issues that make you want to kill the developers with a shovel (especially after Sprint Layout), but overall everything is very good.
• Interactive connection between the circuit and the board (Forward annotate, that’s what it’s called). Those. You added an element to the circuit, and it immediately appeared on the printed circuit board and all that remains is to route it. This allows the circuit to be broken down piece by piece, in manual mode. Adding components one by one to the circuit diagram and writing out the connections. For this reason, Dip Trace was eliminated - there this is done only by re-opening the file with the wiring. Inconvenient.
• Convenient creation and work with libraries. I really liked Eagle here too. Especially the way the component is made there and the fact that you can selectively include libraries, updating them on the fly.
• Cross-platform. I do a lot not only for myself, but also for you. A lot of people sit on Linux/Mac and lose them like target audience I don't want. Eagle is available on these platforms in its native form. No shamanism. There is also KiKad... It looks good, but (like many open source products, yikes) it’s not usable. There, for example, I didn’t find Undo in the PCB editor, but how about catching connections in the schematic? He's still a mess. In five to ten years they might finish it to a sane state, if they don’t kill it :)
• Relative free. It's terribly frustrating to tinker with cracked patches, and the eagle has a completely functional demo mode. Allows spreading in two layers, over an area of ​​100x80mm. Quite normal for home. Those who don't have enough can always find a cure for greed. Eagle is popular and finding a crack is not a problem at all. I just want to warn you - the needle has cunning protection and it likes to burn the office and encrypt projects made in a cracked program. At least I heard about such an ambush. So back up your projects so that they don’t suddenly become unavailable. Well, I recommend using the fourth version of Eagle in this case. It was a normal crack for her. I almost always have enough demo mode. Maybe I'll buy it later =))))
• The presence of an autorouter and the ability to burp the netlist into another tracing system. Look, for example, Shura Lyuberetsky, traced with an Axe. It turned out very sticky. It was especially disturbing for those who are not used to warm tube circuits with smooth curvature of the tracks :)
• Lightness. Unlike all sorts of monsters like Mentor Pads or Altuium Designer, Orel does not lag even on my ancient laptop, not to mention the atomic netbook on which I am writing this text.
• Ease of use. Reading a hundred thousand manuals on how to do this or that was not part of my plans. The needle turned out to be very simple.

Plus Eagle has a powerful scripting language, which allows you to create a lot of voodoo :) I haven’t gone there yet, but judging by what all sorts of ulp scripts do, it can do a lot.

We want! We want! WHERE?
http://cadsoft.de Here!

Excuses
Let me tell you right away that I haven’t been using Eagle for long and I don’t know all its features, so add it in the comments, and I’ll put it all in the FAQ. But I will tell you a number of tricks as the process progresses. As a process, we will build some simple device. Yes, at least a programmer based on FTDI, I have long wanted to adjust it to new realities (Redcat sharpened avrdude and now it itself releases RESET and uncouples the buffers).

I’ll write right away what won’t happen - detailed description buttons. This is tedious and not creative, and you can figure them out yourself in five minutes using the random method and RTFM. Click on the help, read the pop-up tips, everything is clear there. So why should I rant in vain? ;) I will try to describe particularly unobvious moments.

Also, I will not describe in detail the contents of the standard libraries. For the most part, for an amateur, their organization is fear and horror. Especially if this concerns any buttons, connectors, variable resistors. Well, how do we know who produces variable resistor, what did you buy at a radio flea market for 15 rubles? And you will be exhausted by searching too much. So it’s up to your own libs to decide here, and you shouldn’t be lazy about filling them out and completing them.

Reconnaissance in force
So we have a diagram. We need to implement it in hardware. Let's launch Eagle. If you don’t understand where it starts from, then look for the bin folder in the installation directory. The main executor is there. So poke him. Let's start with the main window of the project window.

There's a tree structure there.

Libraries— component libraries. If you open it, you will see a bunch of different libs filled with accessories. You will never need 90% of them, so there is no need to litter them working space. Of course, let them be there just in case, but we will include them selectively in the working environment. A green dot next to the library name means it is included in the environment and is available in item search/selection. There is no need to manually turn off all points; just select Use None from the context menu, and then turn on the ones you need selectively.

Immediately include the following libraries, we will need them:

74хх-eu.lbr standard logic library. atmel.lbr AVR controllers con-berg.lbr here we will take a good USB connector. crystal.lbr all sorts of quartz diode.lbr diodes docu-dummu.lbr primitives of the basic elements. To create your own components you will need ftdichip.lbr, from here we will take our FTDI microcircuit holes.lbr standard holes for fasteners. Convenient sometimes. ic-package.lbr Just some microcircuits in cases. If you are too lazy to create a component. jumpers.lbr Different jumpers microchip.lbr If you use PIC controllers pinhead.lbr Pin connectors rcl.lbr All resistors, capacitors and inductances are here. The most necessary library. ref-packages.lbr Samples of seats for different micro-devices. To create your own libraries. supply1.lbr Signs of supply voltage, ground and power.

Design Rules— Here are the settings for the future printed circuit board. Different tolerances and sizes. It’s important to set everything up right away. Otherwise, you will be tormented to fix it later. Click on default.dru and the settings dialog will open.

Let's immediately go through the tabs and set everything up as we need it.
IN File And Layers We can't pick anything.

Clearance
Distances between paths and all sorts of holes. Click on each field and in the picture you will understand what it means where.

All sizes are in mil - a mil is a thousandth of an inch. So 8mil is 0.008 inches or 0.02cm, which translated into our native millimeters is 0.2mm. It’s a little thin for home use, I wouldn’t do less than 0.3 tracks, there’s a risk of getting defective. In order not to soar the brain with different systems notation, remember that 4mil is 0.1mm and that makes you dance.

I usually set 12mil between different signals and 8 between the same ones.

Distance
The distance between the tracks and the edges of the board, as well as the distance between the holes. I have 40mil everywhere i.e. 1mm.

Sizes
Minimum track width, minimum opening. My track will be at least 0.5mm, i.e. 20mil, and the minimum hole will be 0.8mm i.e. 32mil. If I need less, I’ll put it manually already on

Micro vias are only needed for multilayer boards. This is not a threat to us.

Restring
Dimensions of transition holes and patches. Everything is a little trickier here. Eagle calculates the size of the patch automatically, as a percentage of the hole. This percentage is indicated in the middle column. But there are also limiting values ​​of the border width (not diameter!) Min and Max beyond which it will not crawl out.
I have 12mil - 25% - 30mil. Moreover, these settings are global and suppress the library settings. Those. If the library coin does not fit into this standard, then it will be adjusted to the limits. And don't forget to set the sizes for the Top and Bottom layers. I mean for the top and bottom. We don’t care about internal ones; at best, we will have a two-sided board.

Thus, with a hole diameter of 0.8mm, the edge would have to be 0.2mm, but this comes up against the 20mil limit and the minimum edge would be 0.5mm, and in total the diameter of the patch would be 1.8mm

The same goes for VIA vias. They can be made thinner, but only if you have such thin drills. The thinnest drill I have is 0.5mm.

YES! A very important point that often causes problems. The fact is that many components (especially those with a needle included by default) have pad parameters set to Auto, which means their size depends directly on the DRC settings section. So if you place more spots in the DRC than they can be geometrically located on the component (for example, a USB connector in the example, you can see how its pins are tightly grouped), then the spots will spread out and stick together. This is a jamb! So if something somewhere has slipped and overlapped, then either edit the library or change the DRC.

Shapes
Shape of leads and curvature of corners. You can set the minimum curvature and get nice rounded areas for SMD components :)))) The size of the patch is also set there, but you can leave it in accordance with the libraries, because they will mostly come from there.

Supply
Piglets of power circuits. Usually they lead to solidly filled layers and therefore become cunning. Not solid, but like a separate penny and connected to the fill with thin threads of conductor. This is the so-called thermal barrier. Its essence is that when soldering, a powerful polygon does not absorb heat and the solder does not smear on it with clumsy snot, but is concentrated only on the thermal pad.

Masks
Solder mask distance from component. For you, the thing is almost unnecessary. Because It’s difficult to make a normal mask at home. And no one will really bother with it.

User Language Programs- these are scripts. Eagle has a powerful scripting language that uses something like C. Used for export/import, placement of hole centers, and many other things.

Scripts— Eagle command interface scripts. For example, to adjust all sorts of tolerances, display layers and much more. Comrades are clearly taking an example from AutoCAD :)

CAM Jobs— settings for outputting the drawing to production format. Gerber, for example. You probably won't need it at home.

Projects- Our projects. This is where we will begin now.

Select the Eagle daddy and create it there new project — context menu New Project. A new folder will appear, rename it to something more appropriate than NewProject. I called it USBProg. It will immediately be active, i.e. A green dot will appear on it.

There, through the context menu, add a new scheme New->Shematics. This will open a window with the future diagram.

And let's start drawing
The main idea is to draw the diagram not all at once, but in parts. This will make breeding much easier. At least with manual wiring.

Let's slightly customize the environment - turn on the grid, it will be more comfortable to work with. Click the Grid button and set the grid to ON, and I recommend the Dot style - it’s less noticeable. And do not change the grid pitch under any circumstances, otherwise all the components are tailored to a specific pitch and if you change it, the lines will not fall into the conclusions.

Let's install our FTDI first
Press the ADD button and from the FTDICHIP library add the FT232RL chip to the board; it must be in an SSOP package.

Using the Copy cloning button, replicate the soil and food in the required quantity. We need to connect them to our chip so that it looks like the figure below:

Connections are made by the Net tool, and points at intersections are automatically placed.

You can also do this with the Wire tool. In this case, you must put a dot at the intersection with the connection. And if the intersection is without a connection, then it must be pulled through the intersection and end the line there, otherwise there will be a crosshair that is not immediately visible. And this is an error that will appear in the finished device, after wiring the board.

You can drag objects using the Move operation, and you can rotate them by right-clicking. To drag multiple objects, there is the Group tool, which can be used to select either a frame or by poking along the drawing to outline an outline. To drag multiple objects, after selecting a group, you need to press Ctrl and hold it while holding down right button mouse, drag. It’s not very convenient and I keep swearing about it, but that’s how it is. Group operations are also done in the PCB editor.

Now let’s install our USB connector on the board and get acquainted with the principle of connection via Net names.
The USB connector can be found in the con-berg.lbr library and I recommend installing PN61729-S this standard USB-B connector
His pinout is like this:

• 1 Vcc
• 4 GND

We will clone Earth and Nutrition, but we will simply extend the lines for D+ and D- a few cells and leave them like that. And then, selecting the Label tool, we pierce each of these wires. Text labels with names like N$2 will appear, which is the name of this conductor. But this name doesn’t mean anything to us, so we need to rename them. Take the Name tool and rename the postings from pin 2 to DM, and the postings from pin 3 to DP.

Now do the same with the FT232RL chip. Draw lines from the USBDP and USBDM pins and name them DP and DM respectively. Eagle will ask each time whether the nodes can be merged. Say what you can, and note this fact in your head. Because This is a good mechanism for checking that you connected the nodes without errors or typos.

What happened now is that the connector doesn’t seem to be connected visually, there are no communication lines. But in reality, according to the netlist of connections, there is a connection! This is very convenient when you are drawing a large diagram; it is enough to write down the general points and not create a web of lines in which the devil himself will break his leg.

Instead of tags, you can make tags, as in this picture. The same thing, highlight the name and end with a label with the name of the connection:

So, we've already drawn enough, it's time to start drawing. Go to PCB. To do this, press the Board button. Eagle will ask you if it is possible to make a board from the current circuit, say yes. The Board window will open.

Now it’s time to customize the PCB editor a little for yourself. First, let's turn on the grid again. Here everything very much depends on the grid settings.

My grid settings:

• Size = 0.0025 in This is the total size of the grid along which the movement occurs. Moderately small.
• Multipler = 5 in Display multiplier. So that the grid does not flicker in your eyes. In reality the grid will be smaller than it looks.
• Alt = 0.00125 in Alternate grid size, enabled by pressing and holding the ALT button on the keyboard. I made it smaller so that I could correct something very precisely. You can make it even more precise by pressing the Finest button.

I also went to Options - User Interface and made the background color Colored. He became so beige and yellowish. Much nicer than black.

Now we need to place the components so that the connection lines intersect as little as possible. After all, they should then become paths. Here, move and think about how you will get around all this. Also keep in mind that lines will also come from the other legs later, so spread them out so that there is a margin left. You need to drag and drop elements onto the outlined work field. This is a limitation of our demo; if you don’t place a part outside of this rectangle, it will result in swearing. Move objects with the Move command, while right-clicking rotates them, and clicking on the wheel throws them to the opposite side of the printed circuit board.
We immediately transfer our microcircuit to the bottom side, and its contacts become blue - the color of the bottom layer. The top color is red, but this can be customized.

And now let's start breeding;) Grab the Route tool and poke at the first one you come across that has a green line coming from it. You need to bring it to the end of the route without hitting anything. An exciting game:) With the right mouse button you can select the type of line break; clicking on the wheel moves the line to another layer, placing a transition hole. Shift-clicking simply places a transition hole, but does not make a transition to another layer. Our task now is to separate everything one layer at a time, so we’re spinning as best we can... To remove unsuccessfully routed tracks, there is the Ripup command. It traces both the entire route and parts of it. Ripupit, so to speak;)

At one point, a situation may arise that the track is in fact already connected, but the communication line has not disappeared. Like now:

Here the ground line is thrown through the metal housing of the connector, but the needle doesn’t know about it! And he thinks that the connector mounting pads need to be connected and requires a contact there. Moreover, he left the communication line in a completely inconvenient place. It's OK! Let's take the wire tool and along the top layer (it won't actually exist anyway, so why not?) we'll throw wires between the pads for fastening the USB connector casing. By shorting them. The communication line seems to be no longer needed, but it remains. No problem! We press the Ratsnest button and Eagle realizes that he was wrong in removing this connection.
Sometimes it doesn’t help and the connection doesn’t disappear, becoming an eyesore. Then we do it another way. We draw it immediately from the place where it goes to where we want to take it. I don’t care how, at least directly.

Then we rip it out, it disappears, but the communication line remains in the place we need! So we breed her as we need. It's a bit of a pain, but it's rarely needed.

The separated wires can be moved as we wish with the Move tool, and with Split we can bend it as we please. Adding new joints and correcting angles. Immediately line up the lines so that they are farther from each other and bend without forming dead ends. Otherwise, with LUT, you will be tempted to pick out the remains of the glossy layer from there.

Some of them have been dissolved, let's move on. Let's add the condensers and the rest of the harness - all sorts of LEDs and separate them. By the way, I have an LED in the form of smd 0805. I couldn’t find it in the kit, so I had to draw my own component. Later I will show how this is done. This is what happened.

Schematic diagram and already printed sign:

All that remains is to add a connector and a buffer. I’ll take the buffer in a SOIC case from the 74xx library (damn, just like the Chelyabinsk road code).

I add a buffer and connect the permission inputs. It should be noted that the buffer is made up of several elements. And we add them one by one, and they are written as A, B.

We combine their control pins 1 and 19. And then we install the connector and run the lines to it. The 74HC244 chip has four pass-through buffers in one direction and four in the opposite direction. Their input-output pins are practically opposite each other. So the wiring is very simple. But if you thoughtlessly connect the conclusions on the diagram,

then we end up with a web of lines:


you'll get tired of breeding. Here I usually do it as follows. I take a piece of paper and draw the body on it, and on top of it I draw the elements inside, as well as how they are routed to the pins. Helps you get your bearings. And select the necessary valves.

It turned out confusing in the diagram:


But very transparently on the board:

Then I separate the connections and forward them to FTDI. And here, too, you need to think with your head. We are making a Bitbang programmer, and the FTDI bitbang mode has a number of features. In particular, its pins suitable for banging (designated as IO0..7) are completely interchangeable and according to the FTDI manual, the following pins are suitable for this:

• IO0 - 1
• IO1 - 5
• IO2 - 3
• IO3 - 11
• IO4 - 2
• IO5 - 9
• IO6 - 10
• IO7 - 6

That is, we do not need, for example, that MOSI be on IO6, as I drew it in. We can put it on any of the legs listed above. The same goes for others. That's why I throw them as I please. Then I’ll configure everything programmatically, in the avrdude settings.

The GATE pin is on the edge of the chip, so I throw it on the farthest leg, which is 11 for us.


We register the ENABLE point on the FTDI and immediately trace it, making a small belly down to accommodate the remaining pins.


And then we start thinking again and looking at our feet. We take the outermost protruding point and drive it to FTDI; this will be pin 3 from the buffer. We will drive it into output 10 ftdi. Also everyone else.

Let's add a three-pin connector for USART - since it is there, why not use it? And the two-pin connector on CBUS4 - the fact is that FTDI can generate a clock signal, so why not use it to revive crookedly wired FUSEs?

Let's take him outside. But here’s the problem: there’s no way to forward one line from a three-pin connector directly.

You can put a jumper, you can don’t care (a resistor with zero resistance). And here comes out why I don’t like EAGLE - the impossibility of inserting a damn story with impunity. We have to go back to the schematic and insert another resistor there. And then place it the way we need it. We will do the same with the buffer power supply.

Now we look and understand that something is missing. Power pins of the buffer chip. They are not on the diagram! This means they are not connected.
Where can I get them? After all, they were not installed when we installed the buffer. That's right, they go separately. Take the Invoke tool and poke it into the 74HC244 chip, a dialog will appear from which you need to select the power contacts and plug them into the circuit, connecting them accordingly.

Moreover, looking at the wiring, you understand that it is better to connect the power after the figistor, then the routing will go where it needs to go. And you won't have to circle around.

Now let's outline the board and fill all the unused space with earth. We outline directly on the printed circuit board with the Wire tool, selecting the Dimension layer.

Then we take the Polygon tool, select the layer on which this polygon should be placed (we have Bottom) and draw it somewhere next to the board. If you draw it on the board, it will be difficult to highlight it; all sorts of details will come into focus. If anyone knows how to select an element by name, please let me know.

So, you draw a polygon somewhere. So that it becomes so marked with a dotted line. Then you grab the Info tool and point at the newly created polygon. Set fill parameters:

• Polygon Pour - can be made into a mesh, the mesh pitch is indicated below
• Isolate — distance from the polygon to the tracks. It is set based on the technical process.
• Spacing - the distance between fill lines. If we fill it with a mesh and not a solid polygon.
• Orphans - pouring also isolated pieces of copper. Those. there may just be pieces of the polygon not connected to anything.
• Thermals - make thermal transitions between the polygon and contacts. Definitely turn it on, otherwise you'll be tortured to solder.

The rest is okay, who knows, tell me :)

Then grab the Name tool and name the polygon GND (or whatever your zero points are called). That's it, now he is part of this network. All that remains is to put it on the board. You take the Move tool and pull it by the corners onto our board. All that remains is to press the Ratnest button and the polygon will be filled, ending up with the necessary pins itself. Beauty!

Silkscreen printing
All that's left is to clean up the mess a little. Turn off the copper layers so they don't interfere. This is done through the Display button

Cutting out a layer is done by poking the green field next to its name. Turn off Bottom and Top, also turn off the tValue and bValue layers. You should get a picture like this:

If you don’t have the habit of sculpting symbols on the board from the front side (and with loot they also turn out great, and if you fill it with varnish, the beauty is indescribable - even black letters!), then you can skip this stage. I've been falling in love lately :) So, now we have a mess - all the inscriptions are climbing on top of each other and I don't even understand what. We need to fix it. Select the Smash tool and poke at all the elements in a row. At the same time, they fall apart into their component parts - the element itself and its inscription. All that remains is to grab the Move tool and drag out all the inscriptions by the crosses as you please. Yes, they can be rotated, like other elements. The main thing is not to move any of the details, only the inscriptions!

If you are going to make a board in production, with inscriptions and masks, then I strongly recommend turning on the tStop/bStop mask layers and spreading out the inscriptions so that they do not fall on the mask areas (shaded). Otherwise, the production workers don’t care, they will do as you send, and then you will tear the hair out of your ass - because. You will have to climb the inscriptions onto the mask and have to peel them off.

It should look something like this:

Layers
I mentioned more than once or twice above about some layers. Now it's time to sort this information out in my head. The fact is that the eagle is like Photoshop :) in it all the elements go in layers. And they are also imported (printed). Each layer has its own purpose and it is strongly recommended not to confuse them. Now I will give a brief introduction to layers, why they are needed and how they are used. I could be wrong, but generally true. If something is wrong, correct it :))))

Layers are hidden under the Display button

There are just a ton of them, there may be leftists, but there are a number of main ones and I will describe them.

• Top - copper on top.
• Bottom - copper on the bottom.
• Vias - transition holes.
• Pads - snouts.
• Unrouted - lines of connections that have not yet been routed.
• Dimension — dimensions fees.
• tPlace/bPlace—seats for parts that do not cover contacts. Can be applied to silk screen printing. t for the Top layer b for the Bottom layer.
• tOrigin/bOrigin — crosses of the centers of parts.
• tName/bName - layer with part names. Silkscreen printing that can be applied to the board. Even at home, with the same LUT.
• tValue/bValue - layer with detail values. For example, resistor values. Sometimes it’s useful, you print it and get a ready-made installation layout.
• tStop/bStop is an important layer. Solder mask boundary. The solder mask is the same brilliant green that is used to cover the boards at the factory and hides everything except the spots and pads. If you don’t make sure that the mask is where it is needed and not where it is not needed, then you can get powerful hemorrhoids by ordering a board from production. Peeling off the mask is still a task. Moreover, there will be untinned copper waiting for you under it and soldering it will be a chore. It is better to make sure that the mask is positioned correctly. Especially when you draw the components yourself. At home it is almost not needed. Although some individuals make a solder mask from photoresist at home. IMHO it's perverted.
• tCream/bCream — Mask for solder paste. A special mask is made over this layer, over which solder paste is applied during automated installation. You can try cutting it out and applying the paste with a squeegee, and then bake the board in the oven. Some people do it at home.
• tFinish/bFinish - ХЗ
• tGlue/bGlue - glue mask. Those. A special mask is made over this layer, on which glue is applied for gluing SMD parts before installation. Most likely useless for you. Needed, perhaps, only for automated installation.
• tTest/bTest - ХЗ
• tKeepOut/bKeepOut - overall area of ​​parts. Those. a certain technological distance closer than which parts cannot be placed. Those. Keep Out zones must not overlap. For example, if you place resistors too close, the machine will not be able to place them. Or a transistor radiator that will not allow you to install anything else. In general, it helps to determine the boundaries of parts on the board.
• tRestrict/bRestrict — wiring restriction zone. If you fence off a section of the board with a polygon on Restrict, then the autorouter will not fit there.
• Drill - Drilling points.
• Holes - holes in the board
• Milling - I'm not sure exactly, but it looks like scribing.
• Document - HZ
• Reference - HZ
• tDocu/bDocu - contacts and pin locations. Purely for clarity.

Or look for its broken version on file hosting services. The diagram that we will create is presented below. So let's get started.

Let's launch Eagle. The control panel will open.
Click on Projects to expand the directory tree.

We have two folders: eagle and projects. eagle – located in the “My Documents” folder. projects – in the folder where the Eagle program itself is installed. Right-click on the eagle folder and select New Project from the menu that opens.

We give the project a more meaningful name - right-click on the project folder and select Rename from the menu that opens. I called the project AVR-Board.

Right-click on the project folder and select New > Schematic from the menu that opens

The Schematic Editor will open. Let’s save our diagram right away – menu File > Save As...

Like most other programs, Eagle allows you to perform the same action in several ways - using the top menu, the toolbar (located on the left side), command line and hotkeys. I'm more used to using the toolbar.

How to add components

First, let's add a format to our future diagram.
Left-click on the ADD button

A window will open with a list of used libraries. The list is quite large, and when you don’t know where everything is located, finding the right component is quite a task. Components can be searched in two ways - by sequentially going through all libraries or using the search function.

Formats are located in the frames library. We look for it in the list, open it and select A4L-LOC. Click OK.

Clicking the left mouse button will add a format to the diagram. Right-clicking will rotate the format 90 degrees. By rotating the mouse wheel, we can change the scale of the diagram.

Add a format to the diagram and press Esc twice. Let's save the diagram again. The date of the last save will be displayed in the lower right corner of the format.

Let's add the ATmega8 microcontroller to the circuit.
With the left mouse button click on the ADD button.
AVR microcontrollers are located in the atmel library. Let's try using the search function. Components are searched by name and description. We write mega8* in the search bar and press Enter. The window will display all components that match this request.

Select the ATmega8 microcontroller in a DIP package and click OK. Left-click to add a component to the circuit and press Esc. A list of libraries will open, but it will only show the results of the previous search. We delete mega8* in the line, press Enter - the list of libraries is complete again.

Copy, delete, move and select components

Let's add ceramic capacitors to the circuit. Capacitors, resistors and inductors are located in the library - rcl. Components in two graphic versions - European and American. Select C_EU > C-EU050-025X075 (C-EU), add it to the diagram, and then press Esc twice.
Our circuit should have 6 ceramic capacitors. Let's use the copy function to add the missing ones. Click on the Copy button, hover the cursor over the capacitor and click the left mouse button to copy the element. You can delete unnecessary elements using the Delete button, and move them using the Move button

Sometimes you need to perform some operation on a group of components, for example, remove several capacitors at once. Here's how it's done. Click on Delete button, and then to the Group button. Press and hold left button Use your mouse to select the required components.

Place the cursor over the selected components, right-click and select Delete: Group from the menu that opens.

The components will be removed.
You can select components in another way. Click on the Group button, place the cursor in the desired place in the diagram and click on the left mouse button. Now a straight line stretches behind the cursor from this point. Draw a closed contour with these lines and press the right mouse button. The components included in this contour will be highlighted.

You can replace one component with another using the Replace button. Click on it, look for the required component in the list that opens, click OK. Place the cursor over the corresponding component and click with the left mouse button.

Add the rest of the circuit components yourself. To make your task easier, I list the names of the libraries in which they are all located.

Resistors – rcl > R_EU_
Electrolytic capacitors – rcl > CPOL_EU
Diodes
LEDs – led >LED
Connectors type PLS, PLD – con-lstb
Quartz resonators crystal > CRYSTAL
Voltage stabilizers – linear > 78*
Power connectors – con-jack
Power supply circuits +5V, GND – supply1

The end result should look something like this.

How to connect components together

The components have been added, now they need to be connected to each other.
Click the Wire button on the toolbar
A new panel will appear under the menubar - it allows you to select the desired diagram layer, “line behavior” when drawing, rounding radius, line width and line type.

We won't need these settings now.

Click the left mouse button on the output of any element. Now from this point a green line will stretch behind the mouse - an electrical circuit. We connect it with the component we need and make double click– elements are connected. If you click on the right mouse button while laying/drawing a circuit, the behavior of the circuit will change. In the first case, the chain will be drawn only at angles of 90 degrees, in the second, at 90 and 45 degrees, and so on. Try it and everything will immediately become clear.

When connecting two nets, Eagle does not automatically draw a point; it must be placed manually. Press the Junction button and click the left mouse button to set the points in the desired location.

Each chain is assigned a unique name - N$X, where X is a serial number. If you try to connect two nets with different names, Eagle will display a message.

In the Resulting name field, you need to select a name for the new circuit, if this matters.

You can connect remote (far away) circuits by assigning them the same names. In our circuit, for example, the reset pin must be connected to the programming connector, but it is located near port B. In order not to pull the conductor through the entire circuit, we will do this. Let's extend a small circuit from the reset pin. Let's rename it - click on the Name button, left-click on our circuit and in the window that opens, enter the new name of the circuit - RESET.

To display the name of the circuit on the diagram, press the Label button and left-click on our circuit.

Add a circuit to the programming connector and follow the same steps. When we rename a net, Eagle will ask if we want to connect this net to the RESET net.

Click Yes, now the Reset pin is connected to our connector. To verify this, the circuit can be “illuminated”. Click on the Show button and left-click on the desired chain - it will turn bright green.
Chains can also be moved, deleted and copied.

Drawing a tire

Let's connect one of the ports of the ATmega8 microcontroller to the connector using a bus. Click on the Bus button in the toolbar and just like electrical circuit, draw a bus in the right place in the diagram.

All conductors suitable for the bus must have addresses. They are set in the bus properties. Click on the Info button on the panel, hover the cursor over the bus and left-click. The Properties window opens.

We are interested in the Name field - we must enter the addresses of the conductors in it. Conductor addresses can be specified in two ways: by enumeration - ADC0, ADC1, ADC2, ADC3, ADC4, ADC5 or by array - ADC (the lower index must be less than the higher index, ADC is incorrect). In our case, it is more convenient to specify addresses in an array. Let's ask them.
We connect the microcontroller pins to the bus - press the Net button, left-click on the desired pin and pull the circuit to the bus. We left-click on the bus and select the desired address in the menu that opens - the conductor will be assigned this name.