RAREblog

In this short article you'll learn how to make and use a compact, inexpensive adapter that will allow you to connect a Raspberry Pi Pico/PicoW to Grove I2C peripherals. With a Grove to Stemma QT/Kwiic adapter cable, you can also connect your Pico/PicoW to Adafruit and Sparkfun I2C devices. You'll laso learn a useful hack that lets you connect the 2mm spaced Grove adapters to a 0.1" spaced (2.54mm) pcb. Grow with Grove Regular readers will know I love breakout boards. One of the projects that I've been working on is a Raspberry Pi Locator. It reads updates from the @rpilocator RSS feed, and it tells you when and where Raspberry Pi stock is available. The Pico W will sound a buzzer when there's stock around, but it would be great if it could tell you which stores had the Pis. On OLED display would keep things compact, and I thought I'd hook one up. Seeed studios have a great range of Grove breakouts with an easy-to-use connection system, and I knew...

babelboard bonnet Adafruit's protoBoards lets you make a bread-boarded design permanent, and Seeed Studio's Grove system lets you wire up a prototype really quickly. In this half-day project I combined the two to create a simple, cheap, flexible prototyping system for the Raspberry Pi and Jetson Nano The Grove system is based on standard 4-way connectors which can be used to connect digital, analogue and I2C-based components. I've focused on I2C since most of the robots I build use I2C to interact with their environment. I mentioned the Jetson Nano - a hot topic at the moment, as NVIDIA have just announced a low-cost 2 GB version of the Nano which will be available at the end of the month. One of the clever features of the Nano is that it has a Pi-compatible header, so the bonnet will work on the Nano without modification. Fritzing the design I started by laying out an Adafruit bonnet design using Fritzing. The design is really simple. All it does is connect the pins of the...

Grove RTC The DS1307 RTC (Real Time Clock) is widely available, but adding one to a Raspberry Pi turned out to be a bit of a Yak shave. I'm gradually adding code and wiring instructions to my babelboard hardware and software projects, and I thought it was time to cover an RTC. I had a Grove RTC board from years ago and decided I'd document connecting that to a Raspberry Pi. The need for Battery Power First Yak Shave moment: RTCs normally use a coin battery to maintain power so they can keep time when their host is off, and the battery in my Grove board was way past its use-by date. This happened on Sunday evening, and the local supermarkets were shut, but the local convenience store was open. No CR1220, though, so I had to wait until the next day to get started. While I was waiting I read the data sheet for the DS1307 chip and realised I had another problem. Don't connect this chip directly to your Pi! Seeed Studios describe the DS1307 breakout as P...

micro:bit Keypad using I2C+ MC23008 For some reason there's not a lot on the web about using I2C and SPI with the BBC micro:bit. The I2C and SPI protocols allow single board computers like the micro:bit, the Raspberry Pi and Jetson Nano to drive hundreds of different types of useful peripheral chips. There are lots of widely available drivers for the Raspberry Pi, the Arduino and  Adafruit boards. I've seen fewer for the micro:bit, and I have started writing some more as part of my babelboard project . I am also building a babelboard for the micro:bit. The babelboard project Babelboards allow you to connect a range of I2C and SPI devices to several popular single board computers. The image on the right shows an mcp23S08 reading a hex keypad driven by a micro:bit using SPI. The micro:bit babelboard allows you to connect Grove I2C devices and the Quick2Wire port expander and analog boards. You can get adapters that connect Grove to Qwiik , so you can also con...