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Open-Acidification / AlkalinityTitrator-KiCad

KiCad files for pcb design for Open Acidification Alkalinity Titrator unit
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Switch Raspberry Pi to Arduino Serial from USB to TX/RX lines #7

Open KonradMcClure opened 3 years ago

KonradMcClure commented 3 years ago

Currently the serial connection between the arduino and Raspberry Pi is done over the USB ports. This is a bit silly, considering both have serial TX and RX pins, so this can all be done without the USB connection taking up space and ports. Coincidentally, the last two GPIO pins on the raspberry pi that aren't being used are the TX and RX lines, so nothing even needs to be moved.

If these move, the code in the Alkalinity Titrator repo will need to be updated to use them

KonradMcClure commented 3 years ago

According to this source the Arduino Nano operates at 5V and the Raspberry Pi operates at 3.3V. This means a level-shifter will need to be used to connect the serial lines.

One option, if we want to stick with our various Adafruit components is this level shifter breakout board (which can be found on Digikey here) There should still be room on the PCB right above the Arduino Nano for it. level shifter breakout

KonradMcClure commented 3 years ago

I created a footprint and symbol in kicad for this and started adding it to the PCB. However, there's a bit of a solid wall of traces between the Raspberry Pi TX/RX pins and the A1/A2 pins on here. I didn't feel like rearranging things right now so I'll finish those later.