Filed under: Connecting Clock Components
After making the PCB’s the next stage was to connect the picaxe 18x project board to the main PCB using wire and solder. Then using ribbon cable I connected the main PCB to the display PCB. This was done using two connectors with IDC termination. Once the components were connected together and given power the display did not show anything.
In order to fault find it was necessary to use the oscilloscope. This is a type of electronic test equipment that allows signal voltage to be viewed as a two-dimensional graph (For more info on oscilloscope’s see link). To make the fault finding easier I disconnected the project board from the PCB and connected a protocircuit. It was easier to fault find using the wire switches connected to ground on the protocircuit. This enabled me to check each of the four inputs going into the 4511. Using a probe from the oscilloscope I was able to test the voltage going in and out of the 4511 BCD chip. A line going horizontally across the display registers how much voltage there is. Due to this closer inspection of the main PCB I was able to identify that one of the pins on the 4511 was not connected to ground. This was pin 5 the store input. Using a section of wire I connected pin 5 to ground, once this was connected the circuit and display were functional. I then wired the project board back to the main PCB and this was all functional. I can now start with the programming
