DHT22 to serial ASCII converter.
This converter reads the output from a DHT22 temperature and humidity and converts it to serial ASCII. On the first line it desplays the raw data from the DHT22 as 10 hexidecimal digits. (80 bits) On the second line it displays the humidity and temperature in degrees centigrade. (I have not tested it with negative temperatures yet.) Each reading is initiated by pressing the push button. (The code could be modified to send a reading at regular intervals.
This is the schematic of the converter. (NOTE The labels on the symbol for the PIC12F1822 are wrong as there was no synbol for it in the Eagle library. I used the symbol for a PIC12F629)
This is the schematic of the converter. (NOTE The labels on the symbol for the PIC12F1822 are wrong as there was no synbol for it in the Eagle library. I used the symbol for a PIC12F629)
The output is at a 5 volt TTL level so it will need to be converted to RS232 levels with a MAX232 or similar to connect to a serial port. It could also be connected to a USB port by using a serial to USB converter such as the FTDI FT232RL (These modules are quite cheap on ebay.) Yet another alternative would be to use a Bluetooth module. The information can be displayed on a PC using a terninal emulator program such as "Tera Term"
Source and HEX files.
Source and HEX files.