scottjames / accutemp

wemos d1 shield - accurate thermometer using four sensors, oled 128x64, LDR/CdS, button, RG LED

AccuTemp

wemos d1 shield - accurate thermometer using four sensors, oled 128x64, LDR/CdS, button, RG LED

Accurate temperature measurement wemos d1 shield.

• Wemos D1 Mini shield (ESP8266)
• Uses 4 high precision sensors from different manufacturers (STS35, MCP9804, Si7051, MAX31889)
• Sensors arranged within 11x11 mm square, to share common heat sink (heat source).
• pins D1,D2 for SCL,SDA i2c.
• Button for input (D0)
• CdS LDR sensor (200K) on A0 -- Vdd(3v)
• Red/Green 2 color LED (RG 3-wire CAC leads)
• Pads available for open-drain sensor outputs
• Pads available for several wemos GPIO (solder jumpers as needed)
• OLED 128x64 support with swapable Vcc/Gnd pins to handle different pin styles.

PCB at OSH Park

AccuTemp PCB

BOM at DigiKey

• See XLSX file
• ** NOTE: BOM is sensors and LDO Regulator only **
• other passives are 0603 resistors, 0805 capacitor
• CdS LDR from ebay (200k ohm in dark)
• Red/Green LED (CAC leads) from ebay