6 ms·
I use mine all the time for experiments. They're super useful for doing quick one-off experiments to see if something will work. Sometimes I'll keep using them,
by peckrob 5y ago
I use mine all the time for experiments. They're super useful for doing quick one-off experiments to see if something will work. Sometimes I'll keep using them, other times I'll switch to a different platform.
Friday I was trying to figure out if I could remotely read realtime usage off my power meter. I've tried using a SDR for it but it uses some proprietary frequency hopping system that is difficult to understand and I don't have enough domain knowledge to reliably implement. But it had a debug port on it with what looked like an IR transmitter in it, and some reading online indicated that it might be flashing at a rate that indicates usage. It was too weak (and it was too bright outside) to see it with my phone, so I decided ot just try it out.
30 minutes later I had a Raspi with a IR receiver and lirc and I could confirm that it was pulsing at a rate of 1 pulse per watt-hour (1000 pulses per kWh).
The actual reader implementation I will probably do on esp32 because Raspi is overkill for this, it just needs to read the pulses and broadcast messages to MQTT, and I'll 3D print an enclosure so it's not just taped to the side of the meter. But the Raspi made it really easy to just try this idea out without making any commitments to it. That alone is worth keeping a few around.
- irq-1 5y agoThere is also the $4 Raspberry Pico: https://www.raspberrypi.com/products/raspberry-pi-pico/ https://www.raspberrypi.com/products/raspberry-pi-pico/
- mypastself 5y agoUnless you have embarrassingly poor soldering skills like I do, in which case you have to pay a little extra for pre-soldered pins. But it’s a great little device, and with Thonny and MicroPython, you can get small projects up and running with a really quick turnaround.
- peckrob 5y agoYeah, this is me too. I have essential tremor, so soldering anything takes a great amount of effort. I'll always pay extra for the ease of using the pins.
- markoman 5y agoThis project will make a great blogpost once you complete it. I for one would be interested to hear more. My power meter was replaced a couple of years ago (to a more modern remote-read version) and I would definitely like to directly access usage information in real time.
- yissp 5y agoDo you worry you might get in trouble if a technician sees some strange device attached to your meter? I know you're not actually doing anything wrong, but I feel like it could be awkward trying to explain that to some angry representative of the utility company.
- peckrob 5y agoI do. That's why I was trying every possible way to do this using SDR or some other non-noticeable way. FWIW it's not even really attached to the port, because the port itself is behind the glass, it's just that the IR LED inside the port is visible. So really it's kind of sitting on top of the glass bubble. I also checked the local municipal code (my utility is city-owned) and there doesn't seem to be anything in the code that says I can't do it. That said, I intend to put a notice next to it that says something along the lines of "This is a non-contact measuring device that counts IR pulses. Please call XXX with any questions."