TrH Meter kits are back in stock at Tindie
TrH Meter is a DIY digital room thermometer plus hygrometer that displays temperature and relative humidity on 4 large (1 inch) seven segment LED displays which adjust their brightness level according to the surrounding illumination. It consists of a closed loop system that continuously assesses ambient light condition using an inexpensive light-dependent resistor (LDR) and uses that information to adjust the brightness of the display. An inexpensive DHT11 sensor is used to measure temperature and relative humidity. You can buy a complete TrH Meter kit with a preprogrammed PIC microcontroller for $26.00.