ConnivingPigeon's reef-pi build

[ConnivingPigeon]

Hi all!

I wanted to share my in-progress reef-pi build. I have a small fluval evo 13 gallon tank, so this is certainly overkill, but I enjoy the challenge. I currently have a very simple setup on a breadboard, with a Ph probe, temp sensor, float switch and a relay to turn on/off an ATO pump. I wanted to make something more permanent, and also learn some more about basic PCB designing, so I came up with the following PCB in KiCad.

It supports an Atlas Scientific Ph probe, 3 temp probes, 4 digital GPIOs, two 12v pump relays, and has some additional headers for extensibility -- I pull out two additional I2C headers and an SPI header for output, as well as some voltage pins so I can expand later if I want to.

I sent off the board to be printed, so hopefully in a few weeks I'll have more pics.

 

[theatrus]

Very nice - glad to see more custom boards showing up :)

 

[Sral]

very nice indeed !
I would recommend testing the 4.7k pull-up on the temperature sensors though. I think I have read on an official manufacturer document about stable OneWire buses that they recommend lower resistance when operating on 3.3V

 

[theatrus]

very nice indeed !
I would recommend testing the 4.7k pull-up on the temperature sensors though. I think I have read on an official manufacturer document about stable OneWire buses that they recommend lower resistance when operating on 3.3V

Also, you can generally power the sensors on 5V and use a 3.3V pull-up. Remember most of the sensors don't use real DS18B20 chips so behavior can be pretty puzzling and inconsistent

 

[ConnivingPigeon]

I got the boards!

.... but I didn't get the size of the vias for the spring terminals right :( I'm going to just hack it with some M-F dupont connectors for now while I get a new batch printed

 

[theatrus]

Oh no!

Thats the worst feeling with footprints. Board looks nice.

 

[Orbela]

3D print a mock up or even do a print out and check layout on paper

 

[theatrus]

3D print a mock up or even do a print out and check layout on paper

I've 3d printed PCBs, and for through hole parts this actually works for fit checks (assuming pins are not tiny). Can recommend it.