In this short article, we describe how to bit-bang a DS18B20 or DS18S20 temperature sensor device using PIC firmware written in ‘C’, and output the temperature values to the RS232 port, for logging on a PC, all using the PIC18Flash Development Board published last month.
 The PIC18Flash development board described in Elektor Electronics January 2005 includes a header ‘K8’ that delivers the appropriate processor pins for SPI / Microwire, I2C and 1-Wire communications to external devices. The SPI/Microwire and I2C protocols are supported by dedicated PIC hardware modules, and are quite easy to use as the hardware can be accessed using standard C18 library functions.