Tag Archives: I2C

How to talk to I2C sensors, displays from… Linux

T’other week, I wrote about my work on building a Raspberry Pi RP2040-based I²C host device and some macOS client software to control it. I mentioned that I might get the latter running under Linux too. I now have, and it does.

The matrix display client and the CPU activity display example running on a Raspberry Pi 400
The matrix display client and the CPU activity display example running on a Raspberry Pi 400
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How to talk to I2C sensors, displays from a Mac

This post was originally going to be about building a tool to access I²C devices on a Mac, reaching them via USB and an Excamera Labs I2CMini adaptor board. But then I accidentally snapped the pins and board traces off my I2CMini, so I had to go back to the drawing board. Now it’s about accessing I²C devices on a Mac using a Raspberry Pi Pico, or any other RP2040-based board, as the adaptor.

An I2C matrix display showing my Mac's CPU utilisation graphically
I2C antics: a CPU utilisation readout using an RP2040-based board as an I2C bridge to a matrix LED
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Review: the GrovePi+ Starter Kit

When it comes to hacking hardware there’s an easy way and there’s a hard way.

The hard way involves connecting peripherals direct to one of the standard buses supported by your Raspberry Pi, Arduino, Beaglebone or whatever. Buses like I²C, SPI, UART and 1-Wire. You’ll need to take care with your wiring: have you got the right pull-up or pull-down resistor? Is there too much capacitance in the line?

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(Retro) Review: Raspberry Pi B+

Better late than never. An edited version of this review appeared in The Register in August 2014. I intended to reproduce the original here, but never got round to it. At long last – and a tad late now the Pi 2 is out, of course – here for the record…

You might think that were you a purveyor of a nifty compact computer selling by the millions, you’d consider two years after the debut of your first offering that it was high time you tempted back buyers with a go-faster, more capacious and shinier model. Heck, Apple and others don’t even wait that long: they upgrade products year in, year out.

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