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Harness tester challenge

commaai·harness_tester_challenge·kicad_files/hardware_challenge.kicad_pcb

Harness tester challenge PCB layout, top view — open source NXP board by commaai

About the Harness tester challenge PCB

Harness tester challenge is an open source NXP PCB design by commaai, published on GitHub under the MIT license. It is a 4-layer board measuring 61 × 71 mm, with 25 components from 21 distinct parts.

Its main chip is the Teensy4.1, from the NXP family. Other key parts include the L7805, NEO-M8N, CY8C9560A-24AXIT and MAX2679. By type, the board carries 7 capacitors, 5 ICs, 4 resistors, 3 diodes, 2 connectors and 1 transistor.

From the project

We designed a simple harness testing PCB and wrote some firmware for it. Can you figure out everything wrong with it?

We (mock) designed a simple harness testing PCB and wrote some firmware for it. Unfortunately, this board was designed and firmware was written on a Monday morning.

As a simple wiring harness, we expect them to have a near-zero failure rate, so good testing is critical. This tester is designed to be capable of quickly verifying which pins are connected to which other pins.

Harness tester challenge, from the project README
From the project README

Main components on the Harness tester challenge

L7805Teensy4.1NEO-M8NCY8C9560A-24AXITMAX2679

Harness tester challenge bill of materials (BOM)

25 components, 21 distinct parts.

QtyPartRefs
1
L7805
U1
1
Teensy4.1
U2
1
NEO-M8N
U3
1
CY8C9560A-24AXIT
U4
1
MAX2679
U5
1
SiSS27DN
Q1
1
12V INPUT
J1
1
Cable header
J3
1
ANT-GNSSCP-TH25L1
AE1
1
TEST BUTTON
SW1
1
SMAJ16A
D1
1
PMEG10020ELR
D2
1
ASMB-KTF0-0A306
D3
1
12n
L1
1
1u
C1
4
100n
C2, C3, C4, C5
1
1n
C6
1
10u
C7
1
1k
R1
2
4k7
R2, R3
Show 1 more
QtyPartRefs
1
10k
R4

Harness tester challenge design files

The KiCad project lives in the commaai/harness_tester_challenge repository on GitHub; these links point at the commit this page was built from.

Harness tester challenge: common questions

What microcontroller does the Harness tester challenge use?

The Harness tester challenge is built around the Teensy4.1, from the NXP family.

How big is the Harness tester challenge PCB?

The Harness tester challenge measures 61 × 71 mm, has 4 copper layers and is 1.625 mm thick.

How many components are on the Harness tester challenge?

25 components, from 21 distinct parts. The full bill of materials is listed on this page.

Where can I download the Harness tester challenge design files?

From the commaai/harness_tester_challenge repository on GitHub, which has the KiCad layout and the schematic; the links under Design files point to each one.

Can I use the Harness tester challenge design in my own project?

Yes, under the terms of its MIT license, which commaai chose for the repository.

Can I test firmware for the Harness tester challenge without the hardware?

Yes. HardLabs builds a simulation of the board from its netlist and BOM, so you can run and debug NXP firmware against it before you order a PCB.

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