ESP8266 4x ADC Multiplex Wemos

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

published 8 years ago