One of the functions for my RV monitoring project includes a “power pole” monitor. It would monitor the temperature of the actual power plug. (we had one burn up before, and the plug on the side of the RV too!).
So, the plan is to use a suitable battery (enough power for about two “cloudy days”, a solar panel that would keep said battery charged, and a XIAO ESP32-C3 that reads a DS18B20 temperature sensor and then transmits that back to another inside unit (via ESP-NOW), then goes to sleep. Starts over on wake after about 5 minutes.
So far, the sleep and everything is working just fine.
But now I’m not so sure about the optimum place to put power.
I have a solar panel, supplies nothing but power. A battery. And a solar charger. This one from Adafruit (or one similar) ADA390, and another very similar (Aideepen MCP73871).
The question is, I guess, is where would you power the XAIO board? Tap off the battery, onto the “battery” terminals on the XAIO board? Or just connect the battery (after the solar charger) to the “power” (5V) terminals on the XIAO board? Apply “power” to the XIAO board, and the battery to the battery connection?
I’m not sure if the XIAO board has an actual battery charger, an if that charger circuit would have a problem with the solar charger. I don’t want them fighting each other.
GENERALLY, you would have a battery charging board. Solar into charging board, battery into charging board, and then there would be an output, that goes to the XIAO. Aliexpress has a bunch of all sizes. I would think you don’t need much power for a few days.
HIJACK. Why can’t I post a new topic? I just got a XIAO EE05 display kit, and the bugger won’t give me a pair code. Can’t find any topics about troubleshooting, or on the forums. Blah.
So , it’s a Bot spam protection thing, Just post another reply or two and You will have enough forum credz to get the New Topic button.
One quick note, "
This is a Chinese companies Product Support forum, 'RESPECT is Paramount. I’m sure you’ll have no problems here.
HTH
GL PJ
BTW I would agree with you on the Logic in the answer, should be more of this on the seeed radar.IMO
So far… what I have done is run the solar cell (about 5V out) to the VBus pin on the XIAO board, and the battery to the charge output. There’s a voltage divider (well, two) connected the cell input and the battery + supply.
Seems to work pretty well. The battery holds up a couple of days with no sunshine. (The ESP32 goes to sleep, wakes about every 15 minutes, transmits temp and and both battery and cell voltage then goes back to sleep)
I had one of those solar chargers that maximize output, but the ESP32 didn’t seem to like it. So I decided to bypass it.
As I said, works pretty good so far. I need to seal the ESP32 from moisture and close it up.
I used a cheap solar powered spotlight, like you would find to stake in the ground and put a decorative type spotlight on your house. Not sure of the battery size. Not an 18650, larger than a single AA.
(Ah! HIJACK, hijacking the thread! I get it now, I wasn’t sure at first. Hijack away my friend…
I think for the sealing purpose, you can get an idea from this Solar Powered WiFi Weather Station V3.0 project. This is quite close to what you are doing. It features and ESP32 and several sensors. The whole device is solar powered. It stays outdoor and protected by a 3D printed enclosure.
If only I had a 3-D printer… My wife already worries about never seeing me again when I start working on a new “project”.
I have the old solar light enclosure. I don’t use the light at all, everything fits in the panel for the solar cell. So I’m thinking just “paint” it with wax or parts of it with a UV curing epoxy I have. Protect it from the elements.
My wife was too Until I started Printing things she could use, Watch stand, Fit-bit charge holder, LIDs, Etc.
The win was I printed a Statue of her from a 2D picture.
Truth is She got me the first one for my birthday, and that was 6-7 ears ago, Next to my 2nd Amendment Gear they will need to come heavy and 100 ninja’s DEEP, to take it from me NOW!
The Last one is the S1 it prints Carbon fiber nylon CF-PLA.
what come off of it is nothing Short of Amazing!
Me too. I’m also curious about the optimum way to power the XIAO in this setup. I’d want to avoid any conflict between the solar charger and the XIAO’s charging circuit. The low-power sleep cycle sounds like a good approach for this type of RV monitoring project. And This post I’ve also worked on projects involving an Arcana Calculator, so I’m interested in how similar lightweight applications could work with battery-powered hardware.
PJ 
One will turn into 5 …
