Hi. I am planning to automate my greenhouse as learning project. My first goal is to control two sliding doors to open when temperature reaches value and close when it drops below value. Second, but not so important would be temperature logging. Now i am at plan stage. My plan is to use esp32, power it single 3,7 li-ion battery. Battery charging should be done via TP4056. Considering my power supply i should use 3v geared down DC motors. For motor control I thought to use relay module. My first concern is relay module option is best for lowest power consumption. Second, voltage drop during motor operation.
In one state the relay coil consumes power. Better to use MOSFET based motor drivers.
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Depending on the module, you either need 5V or 3.3V. 3.7V is not an option
Need a new plan!
Insignificant compared to the motors.
Most of the energy will be consumed by the motors.
That will mostly depend on the battery.
Note that mA-hr or A-hr is an indication of battery life. A 1 Amp-hour battery may not be "happy" supplying 1A. The voltage might drop, and of course it will drop as the battery discharges.
You might want to just test the battery and motors before you go too far. Do you have a multimeter to monitor voltage?
If you can increase battery voltage you can use a switchmode "buck" voltage regulator to bring-down the voltage to whatever you need, and the voltage should hold-up as long as the battery can supply enough voltage and current.
Swichmode regulators are highly efficient so when you are stepping-down voltage you'll pull less current from the battery than is going to the motors.
...Linear regulators are inefficient and they typically can't supply enough current for a motor, and with higher current they can overheat.
How much mechanical power will be required to move the door?
I build frame myself. And doors is yet to be made. But I plan to make light door frame with rollers and guide.
Yes
My initial thought was to do 2s battery with buck regulator to power esp32 and use 6v DC motors. But I couldn't find 2s solar charging module. I am thinking that if I try to charge two batteries simultaneously with 1s charger, battery won't last.
Well that's a new element to the original plan.
Maybe you should give us the entire overall picture before we go in circles with various suggestions.
Greenhouses normally use gas struts to open windows, not motors/batteries.
Leo..
Automatic greenhouse vent opener uses special wax, not gas. But this topic not about that.
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Well in my opinion both options 1s or 2s li-ion viable. With one battery I can use TP4056 solar charging module to Charge battery and LDO voltage regulator to power esp32. Motor control will be done via relays. I could power up 3v motors directly from batteries or use boost converter and 6v motors. This solution might create problem that during motor operation battery voltage might drop too low.
You won't find an LDO that will provide a regulated 3.3V out with only 3.7V in
https://randomnerdtutorials.com/power-esp32-esp8266-solar-panels-battery-level-monitoring/
What about this?
Nope
Nope for my application? Or that tutorial is entirely incorrect?
No for the voltage regulator.
Charging a single battery with the solar panel and TP4056 is OK.
I think a boost regulator to go from 3.7V to 5V for the ESP would be the best solution
However can you find 3.7V motors that will work for you?
Otherwise a two battery solution will get complicated.
I know that, but it looks like a car gas strut...
Did you consider a Seeed ESP32-C3 board. It has a low power single core ESP32, a LiPo battery connector and a built-in charger.
Leo..
Many tiny 5-pin smd regulators have a 0.1volt drop at 100mA.
Leo..
This board looks good. but I already have esp32 board. There is also deep sleep function.
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