After tweaking some settings it's actually charging πŸ₯³ only a beat-up lead acid battery so I don't start any fires, and off a tiny solar panel, but I still can't quite believe this actually works 😬

Next step: adapt the firmware to that thing. The instructable this is based on used a normal LCD, but that's too bulky for the lamp. So need to adjust it to work with the OLED screen. Again a bit fiddly, the libraries are only somewhat compatible. But we got text now 😬

Ok, on to the charge controller. This little display seems to have a non standard I2C address configured, but after some fiddling around, I managed to get it to work πŸŽ‰

Put together the battery pack with its battery management system. Only populated one side for now, but it looks like it's working πŸ’ͺ

Working on some hardware prototyping while listening to The talks at @ohsummit

I need to tackle my twitter bookmarks on of these days πŸ™ˆ

Also would be great to have some sort of debugging device πŸ€” does anyone know of a small serial monitor that just connects to the FTDI "port"?

Installed a TTN node to monitor an off-grid solar setup, but it turns out I hit a coverage dead spot πŸ™ˆ I guess I'll have to bring a bigger antenna next time.a

I don't seem to have any P-channel MOSFETs, and neither does the parts library at @munichmakerlab. So I guess I'll have to order a bunch of stuff again, which will take a week. Damn πŸ˜•

I decided on using instructables.com/ARDUINO-SOLA as a reference, but I'll change quite a few things around probably. I don't have the exact same MOSFETs, the voltage dividers don't work for what I'm doing, and I want an OLED display. And who knows what else. So let's do some sketching

How do we charge these? I would've liked to go with one of those cheapo PWM solar chargers from China (got of few around like this one), but while you can dial in their cut-off voltages a bit, they won't adjust far enough for Li-Ion 3S. So DIY it is (for now).

While that's drying, there's some electronics work to do. I don't want to build my own battery pack quite yet, but use these battery holders instead. I can sandwich two of them together for a 3S2P battery, so there are two cells in parallel, and three of these pairs in series.

Probably a good idea to give it a rinse and come back to it later🚿

That whole thing pops out of the base, including the battery connector in the base, and that leaves me with a quite dirty piece of plastic

First side is off, the back side slides out easily now as well. This pole in the middle here has two LEDs in the top part, one of each side. That's the light you see usually. There's another LED (I think) down below and a photodiode to figure out when it gets dark.

Let's take this this apart a bit more. Take off the lenses first, which has just a few regular screws.

Severin boosted

The screw holding that thing together is a funny one. Should be a hex thing on the front, but I didn't have anything that fit, so it's this hack instead πŸ˜†

They normally run on these big chunky 6V batteries, but I'll try to replace them with 18650 Li-Ion batteries, probably 3S for now

My project for this week: turn this warning lamp thing in a small solar charger / battery pack combo. Let's see if I find a way to make that happen...

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