I have been fighting to get my dual display board to function. The first attempt was to use a 50-pin breakout board: FAIL; The second attempt was to pin the ICs to the connector which is an IDC male with a notch (upper-left 1, lower-left, etc.  FAIL; Third and final attempt worked! I said the heck with their number scheme. So I went with an old standard row 1 upper-left pin 1  - 15; lower-right pin  16 - 30 which is now over pin 1.   So without further eloquence here is the 30 pin header interface listed by IC pin number:

IC PinsUpper
Display
Lower
Display
ColorHeader

Pin

Mega256IC PinsUpper
Display
Lower
Display
Color Header PinsMEGA
Pins
1CLSGREEN92232A4A4ORANGE17I2C.A4.25
1CLSPURPLE235031A3A3WHITE14I2C.A3.24
2CLKORANGE272330A2A2BLUE.15I2C.A2.23
2CLKYELLOW264929A1A1GREEN13I2C.A1.22
3WR!WR!BROWN84028A0A0YELLOW16I2C.A0.21
4CE!ORANGE62427FL!GREEN427
4CE!BLUE244827FL!YELLOW545
5RST!RED2825No Pins 23 through 26
5RST!BLUE347
6RD!GREEN2526
6RD!RED746
No Pins 7 through 10
11D0D0RED18I2C.B0.122D7D7GRAY22I2C.B7.8
12D1D1GRAY12I2C.B1.221D6D6WHITE21I2C.B6.7
13D2D2PURPLE11I2C.B2.320D5D5BLACK20I2C.B5.6
14D3D3BROWN19I2C.B3.419D4D4BLUE10I2C.B4.5
15nana18GNDGNDBROWN
16VddVddRED
GRAY
1
2
17GNDGNDBLACK

Notes:

  • The third-time trough was the charm.

I will also use Arduino Mega pins 50, 49, 48, 47 53, 52, 51 for my two switches, using three-bit BCD code and pin 46 for the switch interrupt. I generate the interrupt by using a quad input or-gate Priority Encoder whose output EO goes to a Schmitt Trigger to actually signal for the interrupt. I got the 15 pins by 2 rows with Wire-Wrap tails from Samtec as samples.

Below are a few snaps of the test harness. Without the PanaVice with the PCB holders, this was a daunting task as you have to work on both sides at the same time. I also tried my 3M/AP Products TC-48 which never made contact with the pins, as it was made for plastic or ceramic parts that have different geometries but still fit the normal pin spacing.



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