Since the crystal is optional, I am reusing one of the crystal pins as GPIO RA4. I also "convinced" the .2"-spaced capacitors to squeeze into .1" spacing.
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Despite the mistakes with my PCB, it's salvageable for simple circuits. I'm abandoning one due to poor soldering (it would be a lot of work to repair), but the other two I received from OSH Park can be put to use. I will still spin a new version though.
Since the crystal is optional, I am reusing one of the crystal pins as GPIO RA4. I also "convinced" the .2"-spaced capacitors to squeeze into .1" spacing.
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Those USB FTDI modules work great as power supplies during testing! I'm not using the serial lines at all here.
The PIC16F1459 has a pin called VUSB3V3. An internal LDO generates 3.3V for use with USB. An external capacitor of 0.47uF should be placed between this pin and ground.
When I initially populated my board, and tried to get something going quickly, I thought this would only be necessary once I started using USB. However, without this, PICkit3 sees an ID of zero and fails to program the chip. Various web pages mention that an ID of zero usually means power issues, and sure enough, when I populated this capacitor, PICkit3 started seeing the correct ID. After getting the correct ID, I also had to remove the 100Ω resistors on the PGC/PGD paths to actually get programming going. Some sample circuits have these for protection, but others say to avoid these. I made mistakes with my PCB. For capacitors, I used DipTrace's CAP part from the Discrete library. This had a footprint with holes .1" apart. My capacitors needed .2" spacing. CAP200 from the Discrete library would've worked.
For the ferrite bead, I used IND from the Discrete library. The footprint's holes were too small for the ferrite bead's leads to go through. Hole sizes about same as for pin headers would've worked. I'll probably make a copy of the IND part (to take advantage of its symbol in Schematic view) and replace the footprint in the copy. Order sent to OSH Park on January 24; PCBs arrived February 3rd. Just 10 days! $17.25 for three PCBs.
I designed a general purpose, everyday workhorse PCB around the PIC16F1459. The boards are on their way back from OSH Park, and likely to arrive later today. Here are the DipTrace files on github, and below is a PDF of the schematic:
I wanted to design some PCB's using the PIC16F1459 and PIC18F45K50. I did not find DipTrace libraries for these, so I fired up the DipTrace Component and designed a library for the PIC16F1459 (20-pin DIP version).
This is my first ever DipTrace component library. The pin placements for the schematic few are spaced out quite a bit, but they're "optimized" for a PCB I built around it. I put this library up on github. For the PIC18F45K50, one can start with the built-in PIC18F4550_P component and just modify a few pins. On second thought, there is probably some other 20-pin DIP PIC microcontroller I could've based my PIC16F1459 part on, but I realized that after having done the work. I made my first PCB a few months back. It's a very simple breakout board for the AT26DF161A-SU, a serial flash IC that I'm hoping to experiment with.
Designed with DipTrace and fabricated by OSH Park, it was also a good end-to-end exercise for me. The board was under one square inch, so I thought I'd pay the minimum $5 fee to OSH Park (since they charge $5 per square inch). It turned out that they do not have a minimum, and they charged me the fractional price, $3.10! That's for 3 boards, with free shipping! They're just awesome! I put my DipTrace files on github, along with the rendered images from OSH Park (during submission, they show you the images before asking you to confirm). Here is a photo of two of the real boards I got back: Kuzyatech has a post on how to use DipTrace with OSH Park. It covers Design Rule Check and exporting of files. Based on that post, I made the following batch file to automate the renaming of files after export. @echo off if "%1" == "" goto error mkdir OSHPARK copy Top.gbr "OSHPARK\%1.GTL" copy Bottom.gbr "OSHPARK\%1.GBL" copy TopMask.gbr "OSHPARK\%1.GTS" copy BottomMask.gbr "OSHPARK\%1.GBS" copy TopSilk.gbr "OSHPARK\%1.GTO" copy BottomSilk.gbr "OSHPARK\%1.GBO" copy BoardOutline.gbr "OSHPARK\%1.GKO" copy Through.drl "OSHPARK\%1.XLN" @echo on @echo now go zip up the OSHPARK directory :end @exit /b :error @echo diptrace2oshpark ProjectName
To use: 1. Export files per Kuzyatech's post, but skip the renaming, and let DipTrace name the files as it wishes. Make sure all the files get saved to the same folder. 2. Copy batch script into same folder. 3. From the command shell, execute the script in its new location, giving it your project name as an argument. For example: C:\ExportedFiles> diptrace2oshpark MyPCB 4. There will be a new subfolder named OSHPARK that has the files that OSH Park requires, renamed appropriately.
5. From inside the OSHPARK folder, zip the files into a zip file named after your project. To verify, look inside the zip file and make sure that all the files are at the top level. 6. Submit zip file to OSH Park. |
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