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Microprocessor I/O Test Jig
Designed by Mark Little
This Microporcessor I/O Test Jig is designed to provide an easy means to test digital and analogue I/O pins when developing projects. There are nine (9) green LEDs that can are extended to Connector 1 (the 23-pin connector at the rear), along with twelve (12) switches that connect to earth.

No pull-up resistors are provided for these switches for the sake of flexibility. A pull-up board will be made if it becomes necessary to provide pull-up resistors.
In addition to the digital I/O, three (3) pre-set potentiometers are provided to test analogue inputs. The wipers of those pots are connected to Connect 1 in the foreground of the image. The potentiometers are connected directly across the power rails.
Pin Connection
1 Earth
2 Supply (+5Vor +3.3V)
3 Switch 1
4 Switch 2
5 Switch 3
6 Switch 4
7 Switch 5
8 Switch 6
9 Switch 7
10 Switch 8
11 Switch 9
12 Switch 10
13 Switch 11
14 Switch 12
15 LED Column 1 Row 1
16 LED Column 1 Row 2
17 LED Column 1 Row 3
19 LED Column 2 Row 1
19 LED Column 2 Row 2
20 LED Column 2 Row 3
21 LED Column 3 Row 1
22 LED Column 3 Row 2
23 LED Column 3 Row 3
Pin Connection
1 Earth
2 Potentiometer 1
3 Potentiometer 2
4 Potentiometer 3
Connector 1
Connector 2