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The frame

I designed the PCB to mount in a frame that I also designed. It was to be milled out of Medium-density fiberboard (MDF). MDF is smooth, easy to cut and shape, and paints well. I have a friend, Denny, who is a retired cabinet maker who agreed to make the frame for my project free of charge! I was going to hire him to make more if I decide to start selling the clocks. That was becoming a real possibility since the clock was generating a lot of interest in those that I showed it to. However, after Denny made the frame for the Senior Project clock, he said Continue reading The frame

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The board has been assembled

I assembled the board. Whew, that’s a lot of LEDs to solder! I adjusted the code for the test circuit to work on the new clock. However many of the LEDs refused to light!

At first, I thought I had a bad connection on one of the I/O lines, but then discovered what the actual problem was. Early on, I realized that the processor’s RA4 output was not suitable for driving the LEDs. This pin could only sink current, but not source it. The LED matrix required pins that could both source and sink current. Therefore, I had assigned this pin to drive the buzzer. All the buzzer needed Continue reading The board has been assembled