chipKIT Uno32 and uC32

After some time with the Arduino, I faced with insufficient resources, either memory or processing power.

The Arduino Mega might have been an option, but it's based on the ATmega2560 which remains an 8-bit processor. Price comparison was also a factor.

I went for the 32-bit board chipKIT Uno32 designed by Digilent and built around the Microchip® PIC32MX320F128. The chipKIT uC32 was released later on, with the PIC32MX340F512H.

Main specifications of the Uno32 include 80 Mhz 32-bit MIPS, 128 kB of Flash, 16 kB of RAM, Arduino™ Uno form factor and 42 available I/Os. The uC23 comes with more memory, 512 kB of Flash and 32 kB of RAM.

The programming IDE is exactly the same as for the Arduino, except it handles both AVR and PIC32-based environments through the selection of the board. It is called mpide for multi-platform IDE.

Claiming a 100% compatibility with Arduino may seem misleading since an 80 MHz 32-bit platform doesn't act as a 16 MHz 8-bit one.

Find here how to cope with the compatibility issues.

The IDE or integrated development environment is called MPIDE for Multiple Platform IDE. It comes in two versions, one compatible with the Wiring / Arduino 0023 framework and another with the 1.5 framework.

As Processing-based Wiring-derived Arduino-like, both are platform-agnostic and run on Windows, Mac OS X or Linux.

Looking for more features, I designed embedXcode, a template I could use with Xcode.

Three chipKIT Uno32 Customisations

Here are three customisations for the chipUNO32:

A built-in real time clock,
A shield with an I²C to serial bridge, with 2 I²C connectors and 1 serial connector,
Another shield with a prototype area and 1 serial connector for Serial1.

Conclusion

I like the many GPIOs available, the fast MCU and the large memory, especially on the uC32.

The Uno32 is listed at USD27 while the uC32 goes for USD35. The larger memory is worth the extra USD8, especially when used with the WiFi shield.

The chipKIT WiFi shield is based on the MRF24WG0MA, which unfortunately requires a software TCP/IP stack. There is still a quantified overhead for the libraries provided by Microchip and Digilent, albeit optimised for a light footprint. For example, the WiFiScan sketch weights 80 kB.

Whatever the choice, both boards offer unparalleled value and performance when compared with the Arduino Uno board.

Pros

A 32-bit micro-controller
Lost of I/Os, large memory, fast micro-controller, a second hardware UART port
An Arduino form-factor
Processing-based Wiring-derived Arduino-like MPIDE

Cons

Sketches require some adaptation due to high speed and 32-bit
Two releases of MPIDE, 0023 and 1.5

Wrap-Up

A 32-bit micro-controller at the price of an 8-bit
Early compatibility issues have been solved