I2c Wiring Harness?

APA#2: Hardware Pentesting
1

I’d like to know where one can purchase the i2c harness, I dont have one included with my tigard and i’d like to look at an EEPROM that is embedded on a device but connecting by hand to those pins is gonna make me sad, can anyone suggest where I can get one?

Cheers!
Andrew

2

There’s a few choices for I2c. Photos in this twitter thread: https://twitter.com/securelyfitz/status/1461388618346291203

First, make sure the JTAG-SPI/I2C-SWD switch is in the I2C-SWD mode. That connects an input and output together to make a bidirectional SDA

  1. You can use the JTAG harness on the jtag header to directly connect to devices that have .1" headers
  2. You can use the SPI connector with a SOIC-8 clip, and the wires should be pinned correctly to clip right on to most SOIC-8 I2C EEPROMS as well as many other I2C devices that follow the same convention and put the i2c lines on pins 5&6
  3. You can use the I2C header with STEMMA-QT or QWIIC devices and harnesses from adafruit, sparkfun, and others: What is STEMMA QT? | Adafruit STEMMA & STEMMA QT | Adafruit Learning System

For making your own devices, you can find cheaper sources for “JST SH 1.0-4 Pin Connectors”. The SH 1.0 indicates it’s 1mm pitch compact connectors, not the more common JST 1.27, 2, and 2.54 mm pitch connectors. I have a bunch of premade pigtails from aliexpress, they’re also available cheap on ebay and amazon. Even the ones from sparkfun/adafruit are cheaper than the parts to make them yourself.

-joe

3

Thanks Joe, thats exactly what I am looking for!