ESP8266 π LDR 0..900 mV for ADC 0..1V

*** Light Sensor --- ESP8266: ADC max. 1 V !!! V1 = low current 0.36 mA | V2 = low budget -- LDR Light Resistor / ADC Voltage Light high ~ ADC high Volt = LDR low Ohm Light low ~ ADC low Volt = LDR high Ohm dark light ~ very high resistor (>1 MOhm) low light ~ high resistor (100 kOhm) sun light ~ low resistor (1 kOhm) flash light ~ very low resistor (100 ohm) -- V1: 0.36 mA (100%) .. 0.20 mA (0%) low current version (outdoor usage) R1=6.7k, R2=10k,R3=3.3k,LDR=10..100k 100% flash ~ ADC 0.892 V = LDR 10 Ohm 98% light ~ ADV 0.700 V = LDR 2 KiloOhm 15% light ~ ADC 0.070 V = LDR 85 KiloOhm 0% dark ~ ADC .007 V = LDR 1 MegaOhm Designed by me to use for a solar powered sensor and low current. -- V2: 2.13 mA (100%) .. 0.007 mA (0%) low cost version (flash light damage the adc!) R1=470, LDR=1.08k..500k 100% flash ~ ADC 3.23 V !!! = LDR 10 Ohm 99% light ~ ADV 1.000 V = LDR 1.08 KiloOhm 1% dark ~ ADC 0.007 V = LDR 500 KiloOhm The ESP8266 WittyCloud board use V2 and it works at most environments. If you use the controler outdoor at low temperatures (lower than 5'C) and use a flash light (camera), the ADC / ESP8266 will be damaged!

published 9 years ago