4x ADC pin for Wemos D1 Mini
Vin(d5,d6) = 0.1 to 7 V (power)
Vin(d7,d8) = 0.25 to 0.75 V (resistance)
material 4x ADC-multiplex ~ 0,40€
2x BS170 N-Mosfet
2x Resistor 680k
2x Resistor 1k (optional)
2x N4001 Diode
1x LDR 100k (analog light sensor)
1x NTC 3950 (analog temperature sensor)
A0-pin builtin voltage divider 220k / 100k
GPIO = LOW (GND) internal voltage
D5 = HIGH (3V) solar power 0.1-0.7V ~ 1-7V
D6 = HIGH (3V) battery power 0.1-0.7V ~ 1-7V
D7 = HIGH (3V) light 0.25-0.75V ~ 1k-10M
D8 = HIGH (3V) light 0.25-0.75V ~ 1k-10M
Messure battery + solar + light + temperature
internal: 2.7 Vadc × 1.22 = 3.3 V analog
external: 0.37 Vadc × 10 = 3.7 V battery
external: 0.42 Vadc × 10 = 4.2 V battery
external: 0.60 Vadc × 10 = 6.0 V solar
external: 0.752 Vadc = 500 Ohm resistor
external: 0.750 Vadc = 1 kOhm resistor
external: 0.730 Vadc = 10 kOhm resistor
external: 0.652 Vadc = 50 kOhm resistor
external: 0.575 Vadc = 100 kOhm resistor
external: 0.185 Vadc = 1 MOhm resistor
external: 0.025 Vadc = 10 MOhm resistor
There is only one ADC-pin at ESP8266. With mosfet's and diodes you can extend multiple ADC's to messure voltage of power supply and resistance of analog sensors.
GND *---* (-Battery)
BS170.1-(D) *---[680kOhm]---* (+Battery)
BS170.1-(G) *---[1kOhm]---* (D5.ESP)
BS170.1-(S) *---* (A0.ESP)
GND *---* (-Solar)
BS170.2-(D) *---[680kOhm]---* (+Solar)
BS170.2-(G) *---[1kOhm]---* (D6.ESP)
BS170.2-(S) *---* (A0.ESP)
ESP.D7 *---[LightSensor]---* Diode *--- A0.ESP
ESP.D8 *---[TempSensor]---* Diode *--- A0.ESP
