{"id":2829,"date":"2024-10-08T16:16:35","date_gmt":"2024-10-08T15:16:35","guid":{"rendered":"https:\/\/www.robertprice.co.uk\/robblog\/?p=2829"},"modified":"2024-10-08T16:16:36","modified_gmt":"2024-10-08T15:16:36","slug":"rc2024-part-5-building-and-testing-the-pcb","status":"publish","type":"post","link":"https:\/\/www.robertprice.co.uk\/robblog\/rc2024-part-5-building-and-testing-the-pcb\/","title":{"rendered":"RC2024 – Part 5 – Building And Testing The PCB"},"content":{"rendered":"\n

My prototype PCBs from JLCPCB has arrived!<\/p>\n\n\n\n

\"Rotary<\/a><\/figure>\n\n\n\n

The parts I needed to solder onto the board have also arrived from AliExpress and CPC Farnell.<\/p>\n\n\n\n

I found one very annoying mistake try to solder up the board. I had forgotten to add a sensible spoke width to my copper ground plane. This means the ground plane is soaking up the heat from my soldering iron anytime I try to solder any pin connected to ground. I was able to solder up the board, but those pins took between 10 and 20 seconds to solder. I’m not confident the connection will last.<\/p>\n\n\n\n

In the next iteration of the board I will set the spoke width in the EasyEDA CopperArea properties to 0.3mm. This should still give a good ground connection, but also be easy to solder.<\/p>\n\n\n\n

I’m not happy with the position of some of the text on the board. Once wired up, pins obscure the Port 1 and Port 2 text. The debug port is also obscured. I will move these so they are visible when connected.<\/p>\n\n\n\n

The debug port is a bit too high so the pins are clear of the top of the board. I will move them down.<\/p>\n\n\n\n

I also realised that Spencer calls all his PCBs “modules”, so I will call mine “Rotary Encoder Module”.<\/p>\n\n\n\n

\"Rotary<\/a><\/figure>\n\n\n\n

It was with great excitement I plugged the module into my RC2014 and turned it on. The LEDs for Port 1 were all off, but the LEDs for Port 2 were all on. That didn’t seem right, but then I realised I had only plugged a rotary encoder into Port 1. As Port 2 is returning logic 0, the 74HCT14 was inverting this to logic 1 so the LEDs lit. So it was working as expected. Adding another rotary encoder to Port 2 fixed that.<\/p>\n\n\n\n

The address was set to 0 on the address switches. This meant I could use the same BASIC program I used before to test the rotary encoders<\/a>.<\/p>\n\n\n\n

Turning the encoders the LEDs were flashing in the expected order. The BASIC program was returning “Left” and “Right” depending how I turned the encoder. It was working!<\/p>\n\n\n\n

I decided to test the address switches and so set it them to 01111011, which is hex DE, and decimal 222.<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

I modified the BASIC program to read address DE instead of 0.<\/p>\n\n\n\n

30 LET IN = INP(&HDE)<\/code><\/pre>\n\n\n\n
Running the BASIC program, the module now responds to address DE as expected.<\/p>\n\n\n\n
One final test was to plug in my RC2014 Digital IO module<\/a>. This is set to address 3. I modified the BASIC program so the OUT statement used address 3.<\/p>\n\n\n\n
40 OUT 3,2^COUNTER<\/code><\/pre>\n\n\n\n
I can now use my rotary encoder module to successfully move the LEDs on the Digital I\/O module.<\/p>\n\n\n\n
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