The EFIS panel, now with the lower buttons added, wired up on the back side.
the DH/MDA and BARO rotaries(now actually pots) will be replaced by 2 co-axial rotaries with push button function similar to the ND Mode push button function.
the breadboard with PICkeymatrix64 (PIC16F628, 74LS138, and MAX232) in the 64 input matrix version built on it.
from top, a little fuzzy
closeup of the circuit. Front to back: PIC, LS138, MAX232
from the side, with the row and column (8x8 matrix) inputs/outputs raised up to the clips
on the left, wires going into the PIC (columns) inputs
on the right, wires coming out of the LS138 outputs, with diodes (to prevent ghosting)
the diodes
back of the panel, with all the wires hooked up (except the pots which will be replaced anyway)
again the back of the EFIS panel
The whole thing draws less than 20mA
range is set to 100mA, which means the lower scale is used (0-10) with the pointer at about 2
...Yes, I know this thing is OLD... :-)
screenshot of the PICkeymatrix64 output in a terminal program.
with no interaction from the host, PICkeymatrix64 sends only changed states:
format: row/column:[0|1]CRLF
eg: 3/0:1\r\n
