Since my last update, there were a 19 new guides published to the Adafruit Learning System! There were 6 new product guides, a crazy DIY Darksaber build, a Guitar Hero MIDI Controller, an RGB Matrix Portal CO2 monitor, and so much more!
Favorite New Guide
Use neural signals from your brain’s visual cortex to control electronics. This guide will show you how to use the Nextmind Dev Kit, Unity game development software, and an Adafruit Feather microcontroller board to control a servo motor with your mind & visual focus. This example project translates area of visual focus into the physical position of a servo with attached pointer, but it is just that – an example. You’ll likely think of a million more awesome applications after experimenting a bit.
The Nextmind Dev Kit offers an unusually reliable method for converting neural activity to user input. The device’s sensors measure tiny electrical signals from the visual cortex located at the back of the brain. So, it essentially reads what you’re visually focussing on. This may seem less magical compared to other brain-computer interfaces, but it seems to make the Nextmind much more practical, dependable than other brain-computer interfaces I’ve experimented with.
ALS Deep Cut
With so many guides on the Adafruit Learning System, some amazing guides of years past get buried and lost. ALS Deep Cuts brings these guides back up to the surface.
Not a week goes by in the Adafruit Forums that someone isn’t heartbroken to discover that the NeoPixel and Servo libraries won’t work together in the same Arduino sketch. Fear not, help is on the way!
Rather than just leave you with a “mysterious black box” workaround (an Arduino library), it also seemed a good opportunity to introduce some advanced Arduino programming concepts. If you just want a fix and aren’t interested in a lengthy technical explanation, that’s totally fine! You can skip ahead to the third page, “The TiCoServo Library” and get started.
New Product Guides Week!
This week Adafruit published SIX new product guides!
The Raspberry Pi foundation changed single-board computing when they released the Raspberry Pi computer, now they’re ready to do the same for microcontrollers with the release of the brand new Raspberry Pi Pico. This low-cost microcontroller board features a powerful new chip, the RP2040, and all the fixin’s to get started with embedded electronics projects at a stress-free price.
The Pico is 0.825″ x 2″ and can have headers soldered in for use in a breadboard or perfboard, or can be soldered directly onto a PCB with the castellated pads. There’s 20 pads on each side, with groups of general purpose input-and-output (GPIO) pins interleaved with plenty of ground pins. All of the GPIO pins are 3.3V logic, and are not 5V-safe so stick to 3V! You get a total of 25 GPIO pins (technically there are 26 but IO #15 has a special purpose and should not be used by projects), 3 of those can be analog inputs (the chip has 4 ADC but one is not broken out). There are no true analog output (DAC) pins.
One of our favorite Feathers, the Feather M4 Express, gets a glow-up here with an upgrade to the SAME51 chipset which has built-in CAN bus support! Like its SAMD51 cousin, the ATSAME51J19 comes with a 120MHz Cortex M4 with floating point support and 512KB Flash and 192KB RAM. Your code will zig and zag and zoom, and with a bunch of extra peripherals for support, this will for sure be your favorite new chipset for CAN interfacing projects.
This breakout is for a fascinating chip – it looks like an SPI Flash storage chip (like the GD25Q16) but its really an SD card, in an SMT chip format. What that means is that you wire up like an SD card breakout, and use the SD card libraries you already have for your microcontroller. For example, you can use the built in SD library in Arduino, or for CircuitPython we have an sdcard library. The breakout will act just like a 512 MB sized card with FAT formatting (it’s pre-formatted).
Sensirion Temperature/Humidity sensors are some of the finest & highest-accuracy devices you can get. And finally, we have some that have a true I2C interface for easy reading. The SHT40 sensor is the fourth generation (started at the SHT10 and worked its way up to the top!). The SHT40 has an excellent ±1.8% typical relative humidity accuracy from 25 to 75% and ±0.2 °C typical accuracy from 0 to 75 °C.
Sometimes you’ll find yourself with an I2C bus controller on one side, and an I2C bus device on the other and you gotta keep em (electrically) separated. Maybe because one is Earth-grounded, maybe because you’ve got some funky power monitoring setup, maybe you want to reduce noise.
Whatever it is, you can use the Adafruit ISO1540 Bidirectional I2C Isolator to add full electrical isolation between two sides of an I2C bus. The chip we use, the TI ISO1540 is fully bi-directional, supports up to 1 MHz clock rates, supports clock-stretching, works with 3 to 5V DC power or logic (separate on either side of course), with 2500 V-RMS isolation.
Expand your project possibilities, with the Adafruit AW9523 GPIO Expander and LED Driver Breakout – a cute and powerful I2C expander with a lot of tricks up it’s sleeve.
GPIO expanders work like this: you have a board with some number of GPIO but not enough for your project – maybe you need more buttons or LEDs. You could upgrade to a board with massive number of GPIO like the Grand Central, or you could pop on one of these boards. Connect it over I2C and then you can send/receive I2C commands to control the GPIO pins to write and read them. It’s going to be slower than direct GPIO access, but maybe that doesn’t matter if it takes a millisecond instead of a microsecond. You only need the two I2C pins, and you can even share the I2C port with other sensors and devices. Heck, you can even add more expanders for massive I/O control!