A project log for A Tile Based MacroPad

Using "magic" tiles to assign keystrokes to this MacroPad's keys.

michael-gardiMichael Gardi 09/28/2023 at 17:230 Comments

The first thing I did was to trim the leads on the SS49E sensors and spread them out a bit for easier access.

Then I wired the power connections to all the sensors and the buttons. Obviously a lot of care was taken not to introduce shorts, especially with the tiny hall effect sensors. The perfectionist in me cringes a bit looking at this, but I am determined to keep the BOM down so point-to-point wiring it is.

Next I wired the outputs of the 16 sensors and power to the multiplexer (left below). Finally I connected the pro Micro (right below) to the buttons, multiplexer, and project power.

Here are all the connections.

Arduino pro MicroCD4067BE MultiplexerWire ColorOther
VCC+5VDark OrangeAlso powers the sensors.
GNDGNDBlackProject Ground
A0Common Input (Read the channel selected by S0-S3)White
I/O Pin 2-9Light OrangeButton 1-8
I/O Pin 15S0 (These four outputs select which of the 16 analog channels to read.)Yellow
I/O Pin 14S1Yellow
I/O Pin 16S2Yellow
I/O Pin 10S3Yellow
I0 - I15GreenSensors 1-16
GNDE (This is an inverted chip select pin.)Black

I wrote a quick and dirty test program and discovered a couple of bad solder joints, but everything seems to be working as expected now. Software time.