The I2C-It uses the really convenient I2C / TWI protocol to link several sensors to a single I/O pin, and with many new microcontrollers supporting this feature out-of-the-box, it’s a great way to get many sensors onto your device. We’ve made it even simpler by having a custom Y-cable harness that lets you link two I2C-It modules to any I2C/TWI master device.

This cable features

• A 5-position Master plug (Devantech standard), branching to…
• Two 4-position slave plugs designed to the I2C-It pinout
• Each branch of the “Y” measures 30cm (12″)
• AWG28x8C wire

The slave plug is on standard 0.1″ spacing, with the pinout matching the I2C-It sensor (Vcc / SDA / SCL / Ground). The master plug is also on standard 0.1″ spacing, but with 5 positions to match the Devantech I2C cable standard (Vcc / SDA / SCL / (not used) / Ground).

You’re not limited to using this cable only for your I2C-It. If your device doesn’t use the I2C-It or Devantech I2C / TWI connection standards, it’s quite simple to lift the latch fingers in the plug holder, slide the sockets out, and re-arrange the pinout to whatever you prefer. For instance, you can easily modify it to use the “BlinkM” wiring standard of:

Note: You may have to decrease the size of your I2C / TWI pull-up resistors when using this cable. Our experiments show 4.7k on the SCL / SDA lines work well enough for slaving from one slave port to the other connected to Freeduino SB / Arduino (that’s 24 inches total).