PWM Using NE 555 (PCB with EAGLE. College Paper in French TEC 585)

The PIC Programmer project is out the window (for now), as I was busy with many things (college related, mainly).

The main reason I wanted to do a PIC programmer was to make som PCBs, and to get to program a PIC. The teacher told me that there is everything I need (including parts, programmers and chemicals (reactives) to do that..).

So I’m taking care of college stuff, doing something I wanted to do, for free.

For those of you who don’t know me, people around the world should celebrate the fact I attend classes this year, with kumbayas and all the stuff.

The TEC 585 teacher (A class with boards, circuits, practical stuff as a main focus.. PIC programming, etc..) gave us a circuit which got no indication (parts values, or names, etc…).

So I had to “figure it out” so to speak..

The circuit is to be transformed into a PCB in the Lab, as a “learning by doing” thing, a month or so from now, with the teacher showing us all the stuff, a month or so from now (Things move really slow)

Meanwhile, I did the layout on EAGLE. I’m not very good at it, but it’s respectable. I issued a paper which can be found here:

http://docs.com/GH41

It shows the different steps of the board, ripping routes, and creating ground planes, copper pours, etc…

It’s in french, though, as we don’t study in english at the university.

TP1 TEC 585   Ingénieur Instrumentation (électronique)

U.S.T.H.B

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How To Make A PIC Programmer From Scratch, The Newbie Way

So I had a flu… Wouldn’t go out.. Couldn’t anyway… And decided to learn CadSoft Eagle.

I opened a thread about Microcontrollers recently on the great Electro-tech-online.com , and I wanted to build a PIC Programmer … I’ll eventually buy  a “real” one (PICKit 2 or something), I just wanted to lose my PCB virginity with this project.

Anyway, I wanted something simple, so I exluded de facto clones with microcontrollers which have to be programmed in the first place inside them  (The ones I found had a PIC18 inside, like PICKit2 clones).

Anyway… Eagle thingy..

The project I chose is a JDM Serial PIC Programmer… (JDM stands for Jens Dyekjaer Madsen) which I found here :

http://webspace.webring.com/people/jl/leon_heller/pic.html

And which the author found here :

http://www.jdm.homepage.dk/newpics.htm

He substituted the 25 pin connector with a 9 pin connector ( DB25 – DB9 … RS-232) .. I like the DB9 more.

I worked with the schematic from the original page. Have in mind though that pins like TxD (2) or GND (7) refer to the DB25 Pinout, while I’m going to do a DB9 version.

To get the corresponding pins in a DB9, you can search for something like « RS232 pinout » or « DB9 pinout » or something like that..

Or you can find it directly here :  http://pinouts.ru/SerialPorts/Serial9_pinout.shtml

Anyway … Here are schematics I did…

Notice how angles are « rounded », it’s called « Mitering », there’s a button for it on the left panel.

Here’s ultimately the « Board », revision 4…

I drew a rectangle on the whole surface on vRestrict layer, I didn’t want any Vias in there. I’m a beginner, so I didn’t want to  bother with that just  yet.

I drew two small rectangles under the PIC microcontroller, on two layers tRestrict and bRestrict, they coincide, so you only see one.

I didn’t want any routing under the PIC, because I thought it would be better (Less heat influencing its functionning, and I wanted to diminish the influence of a field that would be created by the the current in a hypothetical route. I know, I know.. Actually, I don’t. I asked questions about this on the forum, if I’m overthinking or not.)

I had a problem as shown in the image, where these rectangles crossed over the pads, and it showed errors when I hit DRC (Design Rules Check), here’s a zoom in:

Note how tiny it is, the pads crossed over the restricted surface, and this provoked an error. Amazing software.

I couldn’t draw accurate enough rectangles to include the whole chip, or “just” the chip. i.e : It was either too small, or a little bit too big.. So I increased the Grid resolution by chosing 5 mils in « Size ». I could draw  my rectangles with more precision.

I managed to have a single sided board before (drawing a rectangle in the tRestrict Layer over the whole board), but NOT with that disposition, and it was a LOT of gymnastic. This one is very symmetrical as you can see here :

Here it is with Dimension, Top, Pads, tNames, tPlaces…

It’s a relatively small board  1.8’’ by 2.135’’.

Here’s an image with all layers..

I asked some questions about design faults on the forum mentionned, if you don’t know it, well you should check it out.