Sunday, 22 September 2013

Three reasons why I like teensy 3.0

I've just been experimenting with the Teensy 3.0, and it's fantastic.

The teensy 3.0 is the latest member of Paul Stoffregen's teensy family. The teensy boards are USB-based micro-controller development environments, like the Arduino but teensy :)

Three reasons why I like teensy 3.0
  • ARM Hardware
  • Arduino Software
  • It's breadboard-friendly
ARM Hardware with lots of extra functionality

Early versions of the teensy used Atmel AVR chips, like the Arduino, but the teensy 3.0 uses an ARM processor.

The  teensy 3.0's CPU is a 32-bit MK20DX128 Cortex-M4 from Freescale. You can run it at up to 96 MHz. That's six times faster than the clock on a typical Arduino, and the speed is matched by plenty of memory for program and data. There's space for 128K bytes of program in flash and 16K bytes of data in RAM. As an added bonus, teensy 3.0 has plenty of pins, both general-purpose and specialised: 34 general-purpose GPIO pins, of which 12 can be used as analogue inputs.

The teensy 3.0 has too many pins to connect to its headers; the extras are brought out to solder pads on the underside of the board.

Arduino Software

These days it's easy to find inexpensive ARM-based development boards with their own development environments, but the teensy 3.0 is different: you develop software for it using the Arduino IDE. Almost  all the Arduino libraries are supported, as are many third-party libraries. I've had a quick play with the LiquidCrystalFast library, which is an improved version of the standard Arduino Text LCD driver; it works really well, and I'll write up the experiment next week.

Teensy Tips

I've found the teensy easy to work with, but I did hit a couple of minor snags which you'll want to avoid.

The first was entirely my fault. By default the teensy comes without header pins. I soldered mine in at an angle, and when I tried to repair my mistake I managed to make a solder bridge between the pins of the processor which was fiddly to remove.  The small form factor of the teensy means that you need to be very careful when soldering the headers.

The second problem was easy to fix. I'm running the Arduino software on a workstation with Linux Mint 15. I'd installed the Arduino environment from the appropriate repository, and had difficulty  in installing the teensy enhancements.

I might have been OK if I had run the installer as root, but instead I decided to remove the sightly outdated version of the Arduino environment and install an up-to-date zip file downloaded form the Arduino website. Once I'd done that, the teensy software installer worked perfectly and I had no trouble programming the device.

Overall the teensy 3.0, like its predecessors, is a well-thought-out product that's great value.

If you're looking for a product that combines the processing power of an ARM CPU with Arduino's ease of use, the teensy 3.0 is a great buy.

You can get it for $19 from Paul Stoffregen's PJRC store; UK customers can buy it for around £19.80 including VAT from a range of local sources, including SK Pang.