Weather station

I built a small weather station (like everyone else) :slight_smile:

-D1 Mini (deepsleep)
-SI1145 UV sensor
-TP4050 charge controller
-Single cell LiPo harvested from a laptop battery
-6V solar panel
-Latching charge circuit, this circuit, once it gets a high signal from the 8266 uses current from the solar panel to hold it high till night time regardless if the high battery voltage has been met and the input turns low. The TP4050 protects from over charge.

The north country where I will return to doesn’t have tones of sunshine therefore I have oversized my solar panels and making use of a latching charge circuit. So every cycle the system checks if the battery is below 3.5V (that is not dead but gives me time to get through the night or till there is some sunshine) it changes the charge state to HIGH, also every cycle it checks if the charge state is high or low and triggers D7 accordingly.

If anyone is interested in the latching circuit let me know and I can post it here.

Yes please Dave.


Taken from the internet so a shout out to whoever owns it but I can’t remember right now…
-Removed C1 because it didn’t do what it was supposed to.
-Added a cap across the base and emitter on T1 so it didn’t trigger as easily. Could probably get by with less because this seems to take a cycle or two to latch, but in my case it isn’t fussy.
-Removed the diode and the relay and just hooked the TP4050 up direct.

R1 100K (I think if this was 10K it might unlatch with a negative but I am out of 10K resistors :frowning: but it also isn’t important for my purpose)
R2 10K
R3 100K
R4 10K

T1 BC547
T2 BC557

CAP 200uF

1 Like

Just got to thinking about it in the actual I totally removed the connection between T1 collector and Solar panels.