Arduino IC Tester

Test 74xx (TTL) and 4xxx (CMOS) logic ICs using an Arduino UNO. Sends test vectors over serial from a Python script, the Arduino applies them to the chip under test and reports back whether outputs match expectations.

Based on the work done by JorBi.

Requirements

• Arduino UNO
• PlatformIO (for building/flashing the firmware)
• Python 3 with pyserial
• 680 Ohm resistors between the Arduino pins and the IC under test

Setup

1. Flash the firmware to the Arduino:

   cd firmware
   pio run -t upload

2. Install the Python dependency:

   pip install pyserial

Pin mapping

The IC pins are mapped to Arduino pins as follows. The mapping shifts based on IC package size (14-pin or 16-pin) so the IC is always centered.

IC pin (14-pin)	IC pin (16-pin)	Arduino pin
-	1	6
1	2	7
2	3	8
3	4	9
4	5	10
5	6	11
6	7	12
7	8	GND
8	9	5
9	10	4
10	11	3
11	12	2
12	13	13
13	14	A0
14	15	A1
-	16	A2

Usage

python3 test.py <serial-port> <test-file>

Test files are in the data/ directory, named as <pin-count>-<chip-number>.dat (e.g. 16-74139.dat). Over 170 chips are included.

The script exits with code 0 if all tests pass, or 1 if any output mismatch is detected.

Example

A chip that fails (mismatched outputs shown with X: prefix):

$ python3 test.py /dev/ttyACM0 data/16-74139.dat
RST
-> 101HHHHGHHHH011V
<- O:101HHHHGHHHH011V
-> 110HHHHGHHHH101V
<- X:110LHHHGHHHH101V
-> 000LHHHGHHHL000V
<- O:000LHHHGHHHL000V
-> 010HLHHGHHLH010V
<- X:010LLHHGHHLH010V
RST

Test vector format

Each character in a test vector represents one IC pin:

Symbol	Meaning
0	Drive pin LOW (input)
1	Drive pin HIGH (input)
C	Clock pulse (LOW-HIGH-LOW trigger)
L	Expect LOW output
H	Expect HIGH output
X	Don't care (output ignored)
G	GND (fixed by hardware)
V	VCC (supply voltage)

License

Unlicense - public domain.