Another PCB

Published on 2017-10-31 in µGame.

Today I received a big batch of PCBs from OSHpark, and one of those was the next revision of the µGame PCB. There is a number of improvements there:

• The PCB is wider (42x50mm) giving me more room, but still fits in the 5x5cm limit of many board houses.

• The buttons are spaced a little wider.

• I used non-clicking buttons this time.

• The only parts on the back side are the battery and the speaker.

• I used a smaller reset button.

• The active part of the display is centered on the PCB.

• There are footprints for 2 different battery holders.

• An analog pin connected to the battery through a voltage divider, for monitoring charge levels.

• Two of the button pins are swapped (left and down).

Immediately after assembling the board I realized one more change: the USB 5V rail is connected directly to GND. Oops. That happened when I moved the button pads around, and made one of them touch the 5V trace. Fortunately cutting the trace and replacing it with a wire fixed it, and there was no damage.\

But that means I need yet another version soon. To not waste my OSHpark coupons, I quickly tested the last feature of the board — sound. This one has a piezo speaker directly connected to the DAC pin. As you can expect, it’s really quiet. Hmm, ok, that means that the next version will need a magnetic speaker and an amplifier. But where can I fit them?

After taking some measurements of the new boards, I found a solution. I moved the fire buttons further from the edge (they aren’t very comfortable they way they are now), and put the audio circuit in the freed space. It’s not even very cramped — each component has lots of space around it. Of course the tiny 4mm speaker won’t have great quality, but should be better than the piezo, and now I only have the battery on the back!

I need to finish a couple of other boards, and then I’m making another order.