ESP8266 Community Forum

- Wed Jul 22, 2020 2:16 am #88002 Have you got a window nearby where you can put a solar panel?

Levels from a small 5V solar panel powering a ESP-12F, 2x temp sensors, 2x soil sensors and a light sensor. It is summer which helps and I have a four battery lipo pack. WIFI turns on and off to transmit every 15min.

- Wed Jul 22, 2020 3:20 am #88004 I think I’ll try to make the circuit work on 2.8v and see what happens.

Do you have a 2.8v buck converter to recommend?

Thanks so much. You’ve been extremely helpful.

- Wed Jul 22, 2020 5:33 pm #88013 I'm actually still looking round - found a few but always interested in new units. What we're looking for in order of importance is:
- Vout 2.8V
- Iout >300mA but >500mA is better
- efficiency as high as possible in the operating current band >90% if possible in range 20mA - 120mA
- lowest EMI you can find since it's a Wifi radio chip
- pass thru/100% duty cycle capable
- Vin (min) 2.5V
- Vin (max) dependent but could be up to 12V if you want to use for both powered and battery, but 5V if you're looking at USB and battery/solar

and a minimum of external components. You prob also want cheap too, but weigh up total cost of design and build.

- Wed Jul 22, 2020 5:35 pm #88014

I think I’ll try to make the circuit work on 2.8v and see what happens.

Do you have a lab power supply unit? That was the best investment I ever made in this space. It's fantastic to be able to dial up a fixed voltage and a maximum current draw and then alter those to simulate a draining battery or to see the effect of different voltage levels on sensors, data bus etc.