Norwegian software developer Andreas Eriksen has put together a laptop, of sorts, which boasts "a battery life measured in years" — and is programmed in Lisp for good measure: the PotatoP.
"The word 'Potato' is often used to describe an underpowered/poorly performing device. 'This video must have been filmed with a potato!' This device is intentionally underspecced to ensure long battery life," Eriksen explains of the project's unusual name. "The 'toP' suffix refers to the intended eventual laptop form factor. The suffix 'p' is used for LISP predicates — functions that return true or false, like '
evenp' or '
primep' for numbers. Is it a potato or not? It depends on your point of view!"
The PotatoP prototype, which is more of a luggable than a traditional laptop, is built using exclusively low-power parts. Its heart is a SparkFun Artemis module, which has a single low-power Arm Cortex-M4F core running at up to 96MHz and Bluetooth 5.0 Low Energy (BLE) connectivity. On this, Eriksen runs a modified port of uLisp, a Lisp designed specifically with microcontrollers in mind, dubbed PotatOS.
With portable computers, the display is often the most power-hungry component. To avoid draining too much power there, Eriksen has opted for a compact 4.4" SHARP Memory Display — a technology mid-way between ePaper and traditional liquid crystal displays (LCDs) that lacks a backlight and draws a minimum of power.
With a microcontroller heart and a low-power display, the resulting prototype is impressively energy efficient. With a 12Ah lithium-polymer battery inserted, and a small solar cell fitted to the right of the screen to top it up, Eriksen claims the prototype can run for "up to two years, depending on ambient light" — with a view to making the finished version operate indefinitely on ambient light harvesting alone.