Media thread - 2 April 2024, 15:03

A photo of three small dark blue printed circuit boards, two are BME280 temperature/humidity/atmospheric pressure sensors and one is a splitter with little connectors on all four sides, plus a selection of cables.

Yessss, new (small) project time!

Posted on 2 April 2024, 15:03

A photo of a small blue circuit board that's hanging by its wires from a piece of wood that's attached to the side of our back room. Towards the end of the wood there's also a blue box with a little fan vent in it (a Plantower PMS5003 air quality sensor) and a small white plastic enclosure that houses the existing DHT22 temperature/humidity sensor. And at the VERY end is my extremely dodgy solution to avoiding getting the sensors wet: a plastic tupperware that I've screwed into the end of the wood so it shields the sensors.

And we're alive! That was quite straightforward, I found a MicroPython library for the BME280 (https://github.com/robert-hh/BME280) and updated my sensor code (https://github.com/VirtualWolf/esp32-sensor-reader-mqtt) so it can use either the DHT22 or the BME280. And as a fun additional point, the BME280 library also calculates the dew point based on the current temperature and relative humidity! I don't have it running "in production" yet, I've just got it hooked up to a spare ESP32 and it's sending its data to an MQTT broker running on our Mac mini so I can keep an eye on it for a while, but it's very interesting comparing the values between the two sensors... right now the DHT22 says it's 20.2˚C and 94% humidity outside, the BME280 says 19.9˚C but only 71% humidity. I also want to get a better enclosure for the whole setup as well, I'll think I'll ask a friend who has a 3D printer to print me out one of the multitude of Stevenson screens that seem to be out there.

our house diy darkroom esp32

Posted on 3 April 2024, 20:02

A photo of a small microcontroller board hanging from the side of my laptop, with four thin cables going from some of the pins on it into a single small connector that's connected to a very small square circuit board that is the temperature sensor. There's red heatshrink around where the cables are joined, and there's a second one of these connector-to-separate-cable, well, cables sitting unplugged on the desk as well.

Tonight I did a bit of soldering for the first time in a while! My shiny new BME280 temperature sensors have this very handy relatively standard four-pin connector on them for use with I2C, but ESP32 boards I'm using (the HUZZAH32 from Adafruit) don't have it and only have standard bare headers. So I took one of the cables with the new connector on both ends, chopped it in half, chopped four of the separate female "DuPont" connectors I already had in half as well, and soldered them together, and bam, easy connection!

our house diy darkroom esp32

Posted on 4 April 2024, 21:45

A screenshot from my Grafana dashboard showing two "gauge" type panels, one for the dew point and one for the atmospheric pressure.

I did a bunch more hacking on my ESP32 sensor reader code today, deployed the new BME280 into "production" outside, and got my Grafana dashboards updated! And I was able to do it completely successfully without needing to actually plug the ESP32s into my computer to update anything, the remote-updating code worked a treat. The new sensor is remarkably close to what the Bureau of Meteorology is reporting: the sensor says it's 17.5˚C, 95% humidity, dew point of 16.6˚C and atmospheric pressure of 1017hPa, versus the BoM that says the temperature is 17.8˚C, 94% humidity, dew point of 16.8˚C, and atmospheric pressure of 1019hPa.

diy screenshot nerd shit esp32 grafana

Posted on 5 April 2024, 21:50