Following on from my post Arduino based Solar PV and Hot water monitoring and logging we have designed and created the new PCB (printed circuit boards) for the MCP9801 temperature sensors and also a PCB to hold a mains relay for switching the solar water pump on and off via our mains inverter on the PV system.
The PCBs where designed using the free version of Diptrace and then the design transferred to some single sided pcb using iron transfer sheets. The temperature sensor chip has its internal address assigned by putting 3 of the pins to either 5V or ground so each board was designed to have a unique ID.
The boards were then etched and cleaned prior to being cut into the individual PCB's and the MCP9801 temperature sensor soldered in place.
The MCP9801 temperature sensor was soldered to the board and a strip of 4 way edge connector was added for the connecting cables.
Each board was then tested on the Arduino and using the custom shield with the RTC (real time clock) and new sets of connecting pins for each of the external sensors.
The completed PCB's were cleaned ready to be painted with a protective coat of high temperature silicone to protect them when fitted next to the water pipes and hot water cylinder.
The completed PCB tempature sensor boards.