Raspberry Pi Zero,
BME280 to read the temperature humidity and barometric pressure
RV3208 Real time clock
And three 0.96 inch 160 x 80 color LCD’s
The LCD’s are connected to SPI1 and each have their own chip select wired to the Pi.
The code is a modified Pimorni Enviro+ all-in-one-mini.py file.
The temperature and humidity values are plotted every 5 seconds for about 13 minutes of plots across the screen.
Any faster and its hard to see a trend up or down. Any slower and the graph gets jerky and disconnected.
The pressure is plotted every 45 seconds for 2 hours of plots across the screen.
The pressure changes so slowly you need a long plot to see a trend.
The display show 5.5 c change in temp, 5.5% change in humidity and a 5.5mb change in pressure.
80 pixels minus the 25 for the header at the top. And each pixel is 0.1 so 55 x 0.1 for 5.5 units vertically.
The button in front of the Pi is to command a shutdown. The one behind is for boot up. And the switch by the power in turns the three screens backlights off.
I see I got a couple of likes. This was a very fulfilling project. It looks kind of prototype ish, but it is fully functional. I don’t have access to a 3D printer so its make do with what’s at hand.
I love the tidy wiring. Have you ever thought about designing a custom PCB for it? It could make it a bit more compact, if you cared about that.
I usually go all color coded but decided to go with mostly white on white this time.
I was thinking a custom board would be nice / cool. That’s a fair sized board but it still ends up being a bit cramped wiring wise. Having the header / GPIO breakout for the Pi on one end was a big plus though.
Bigger displays would be my next upgrade. Something like the PICO 1.14” 240x135 pixel IPS LCD screen. Or even a little bigger. Stacked vertically instead of side by side.
I’ll likely poke around Adafruit for something at some point. My projects like this never seem to be “finished”. After i use them for a while I have a “this would be nice” or “I need to change that” moment lol.
Would you even go for something larger like a ~3" TFT screen, and just have all of the graphs on a single screen? It’s a bit expensive, but I love Pimoroni’s Hyperpixel, which still leaves I2C pins exposed. You can cram a surprising amount of data onto it.
If I go with bigger SPI displays its minimal code change, hopefully. If I switch to a hyperpixel I’m into big changes, Not sure I have those skills?