I’ve been experimenting with SPI and I2C on my Beaglebone lately. When I first tried using them at the beginning of the year, I found they required a level of Linux Kung Fu that was beyond me. However, both of these protocols are now supported from “userland” applications in both Angstrom and Ubuntu. A Google search turns up plentyofworkingexamples for SPI and I2C on the Beaglebone, along with some more advancedprojects. I think the water’s safe safe for the rest of us.
I’m going to begin with SPI. Ultimately I’ll be using a graphical LCD, specifically anAdafruit ST7565-based LCD, but in this article I’m going to use a simpler character LCD backpack, also from Adafruit, that uses the popular and well-documented 74HC595 SPI chip.
From the fine people who have brought us the Beagle Board, we now have a smaller, lighter, but powerful single board linux computer, Beagle Bone! We like this move to a more compact and integrated SBC. For example, there is onboard Ethernet and USB host, as well as a USB client interface (a FTDI chip for shell access). It even comes preloaded with Angstrom Linux on the 4 GB microSD card!
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, or even use Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for MakeCode, CircuitPython, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.