Solar Powered Soil Moisture Sensor

[flopp]

@Huczas said:

Could you show better scetch how you connect electicaly everything? how you sending data from arduino pro mini to Domoticz?

In your scetch I see only power->battery->step-up->MCU

Electric connection as the attached schematic and NRF you connect according to MySensors instruction.
Data is sent through the NRF with attached sketch

[flopp]

@AWI
Ok I will try to put it somewhere else and also with some delay before reading analog.
Thanks

[flopp]

@AWI said:

@flopp I had exactly the same problem with a solar powered node. I solved it by moving the battery measurement around in the sketch. The analog measurement is sensitive..
Do you use voltage divider or direct from battery to analog input?
I use direct from battery.

[flopp]

Updated electric sketch with Connectors. This is useful if the battery gets empty then you need to disconnect Arduino so the battery can get charged.

[AWI]

@flopp a voltage divider as I use a rechargeable Li -cell (3.7 v)

[pettib]

@flopp Maybe i miss something but I think the connector should be mounted between the battery and the Vin on the step-up. You mounted it on the A0, it´s just the voltage check port.

In the original lamp there was what i think is a charge regulator between the solar cell and the batteri, did you keep that one or you just put the solar cell to the battery ?

Thanks for a nice idé to use this lamp.

[flopp]

@pettib said:

@flopp Maybe i miss something but I think the connector should be mounted between the battery and the Vin on the step-up. You mounted it on the A0, it´s just the voltage check port.

Thanks, I was to quick when adding the connectors

In the original lamp there was what i think is a charge regulator between the solar cell and the batteri, did you keep that one or you just put the solar cell to the battery ?

I removed the small IC, YX8108. Below is a schematic for YX8108

[pettib]

@flopp Is it the led or the solar cell that is working as light sensor ? If i remove the led and measure on the pins there is always power, even if it´s in daylight. So it should be possible to get the power to the step-up Vin from the LED pin, This way we can keep the on/off switch and the (YX8018) Mine is marked HW012.

[flopp]

@pettib said:

@flopp Is it the led or the solar cell that is working as light sensor ?

Solar.
First I used the YX8108 but I noticed as long as there is power out from solar(sunshine) the LED doesn't get any power, when the power is low(~0,3V) the LED gets power.

[pettib]

@flopp I found this link. https://ez.analog.com/community/university-program/blog/2014/11/14/hacking-an-led-solar-garden-light
The strange thing is that i can´t get the power on the led pin to go low. But i will remove the IC anyway. I made one light 2 days ago but the battery was empty just the day after and i was not able to get it fully charged again. Maybe some bad connection. I will try a new one today.

[flopp]

@pettib
Did you remove the power from battery to Arduino when you tried to charge it again?
I tried to charge r battery for 1-2 days when I had arduino connected, didn't work. After I removed it and out the "lamp" in the sun for 5 hours I could connect the Arduino again and then I was on track again.

[pettib]

@flopp I think it´s was some bad connections. The new one is working very good.

[flopp]

@pettib
Nice

[doug]

@flopp

Hi I know its a bit off topic but what controller are you using to create the graph?

[AWI]

@doug Not my turn :blush: but the Graphs are std. Domoticz..

[punter9]

side thought

why not write your sleep setting as a variable on the arduino side that is dependent on battery voltage?

if v>(full charge) sleep x hours
if v>(half charge) sleep for y hours
if v<(close to terminal voltage) sleep for z hours/days

[flopp]

@punter9 said:

side thought

why not write your sleep setting as a variable on the arduino side that is dependent on battery voltage?

if v>(full charge) sleep x hours
if v>(half charge) sleep for y hours
if v<(close to terminal voltage) sleep for z hours/days
I don't see that it is needed. It will be no problem to send data every 30 min even when the sun is not shining. During a grey day I had vintage around 1.0-1.2.

The idea is useful if you think/know that the solar will not charge your battery

[punter9]

@flopp
sure is, It looks like this sketch already has already picked a set single point sleep time that achieved the discharge gradient being less than the charge gradient looking at the angles on the 7 day graph.

My question is why wouldn't you write an algorithm for your sleep setting so you don't have to mess with it if you get a cloudy week etc? You have variable charge gradients depending on weather so why not have a simple variable discharge gradient?

A simple one would be case A - sunny day discharge gradient B- very cloudy day discharge gradient C- emergency charge/top off battery

you could write an equation based off your existing data but honestly you probably wouldn't get much out of it past the simple set listed above that cover 99% of conditions you will see.

[flopp]

@punter9 said:

@flopp
sure is, It looks like this sketch already has already picked a set single point sleep time that achieved the discharge gradient being less than the charge gradient looking at the angles on the 7 day graph.

My question is why wouldn't you write an algorithm for your sleep setting so you don't have to mess with it if you get a cloudy week etc? You have variable charge gradients depending on weather so why not have a simple variable discharge gradient (or complex if you want to make an algorithm off the charted data) ?

At the moment I don't need it. But if I see that the battery gets drained to much, because of bad weather, I may be use your idea.

[punter9]

ha you are on it! caught me editing!

anyways I love your idea, I can guarantee I am looking for these little lights to be on sale every time I go out. This maxes out the clever scale.