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We have several projects that have low pin counts and require some form of connectivity. We found the DFRobot Beetle BLE to be a great fit for those projects (some of the builds will be documented; we’ll update this post as the build posts are updated).
It’s basically an Uno with a reduced pin count, so you get the expected functionality, just less of it:
- Digital: 4
- Analog: 4
- PWM: 2
- UART: 1
- I2C: 1
- Micro USB: 1
- ~ 29mm x 33mm
There are also dual ICSP interfaces (unpopulated), one for the 328P, and one for the CC2540 BLE chip.
The docs state it’ll take up to 8V (although we’ve only ever used USB or a reasonable 5V supply).
The I2C (SCL/SCA) and UART (TX/RX) pins are also broken out on the bottom of the board as pads: you’ll need to tweak your normal dev process if you plan on utilizing that functionality.
Using The Beetle BLE
It shows up as an Uno–doesn’t get much easier than that! Under OS X the port shows up as a USB modem as you’d expect, with the additional “Arduino/Genuino Uno” tag. Since it’s an Uno, all default Uno sketches (that respect the Beetle BLE’s limited IO) should work right out of the box.
What is it not for?
- IO-heavy projects
- Forget standard headers and breadboarding 🙁
- Trivially mounting: it’s an odd shape (wearables, anyone?)
- TODO 3D Printed Simple Mount
We’re writing up a complete review with some tips for getting started and simple starter apps. We’re also using the board to power a tracked smart car chassis–both the chassis and build project will have their own posts.
There are a lot of similar boards these days, our favorites are products from the Adafruit Feather line:
Those are larger boards with a full complement of IO, and a wide variety of add-ons (“Feather Wings” in Adafruit-speak). For demanding projects they’re probably a better choice. (Quick and full reviews coming, naturally.) They’re also more expensive (by about $10-15), so if you don’t need the additional power for a specific project, the Beetle BLE is a great little board.