Makers Peter Mather, Geoff Graham, and Mick Ames has added another string to the Raspberry Pi Pico’s bow: A BASIC interpreter, largely Microsoft BASIC compatible, turning it into a tiny interactive microcomputer dubbed the PicoMite.
“The emphasis with MMBasic is on ease of use and development,” Graham explains of his custom firmware. “The development cycle is very fast with the ability to instantly switch from edit to run. Errors are listed in plain English and when an error does occur a single keystroke will invoke the built in editor with the cursor positioned on the line that caused the error.”
A blast from the past: PicoMite turns your Raspberry Pi Pico into a Microsoft GW-BASIC-style micro. (📷: Geoff Graham)
The PicoMite firmware’s implementation of MMBasic offers what Graham describes as “a large subset” of the functionality found in Microsoft’s classic GW-BASIC, and builds on Graham’s earlier work with the Micromite — an MMBasic implementation on Microchip PIC32 microcontrollers. “Most programs written for the Micromite can be run [on the PicoMite],” Graham promises, “with little or no change.”
On the Raspberry Pi Pico front, MMBasic includes support for all the standard features of the RP2040 microcontroller: digital general-purpose input/output (GPIO) pins, serial connectivity, I2C and SPI buses, the analog-to-digital converters (ADCs), adjusting the CPU clock, and even the programmable input/output (PIO) blocks. It also includes support for external hardware including SD Cards, various display panels and touchscreen panels, external battery-backed real-time clocks, infrared receivers, environmental sensor, the HC-SR04 ultrasonic distance sensor, numeric keypads, and WS2812 addressable RGB LEDs.
The software includes tools for creating graphical interfaces, complete with touchscreen support. (📷: Geoff Graham)
The PicoMite project isn’t the first alternative programming language to land on the Raspberry Pi Pico: Since the board’s launch we’ve seen block-based visual MicroPython environments, the Mecrisp-Stellaris port of Forth, a proof-of-concept Lua environment, and more.
A compiled PicoMite firmware for the Raspberry Pi Pico is available, along with an impressive 160-page user manual, for free download on Graham’s website; the source code, which in theory should be portable to other boards built around the same Raspberry Pi RP2040 microcontroller, is available on GitHub under a custom open source license.