The “W” signifies that the board includes wireless. Interestingly, the wireless chip is an Infineon CYW43439) which is itself a microcontroller running its own ARM Cortex chip (M3). The Pico’s USB device includes another ARM microcontroller. So, with the dual Cortex (or Hazard) chips that are user programmable, and the 8 PIOs, these devices really pack a punch.

As a result of adding the wireless (microcontroller) chip to the Pico, the Pico W’s on-board LED is accessible only through the CYW43439. Yeah, weird but it makes for an interesting solution.

I’ve been working through Google’s Comprehensive Rust and, for the past couple of weeks, the Bare Metal Rust standalone course that uses the (excellent) micro:bit v2 that has a Nordic Semiconductor nRF52833 (an ARM Cortex-M4; interestingly its USB interface is also implemented using an ARM Cortex M0).

There’s a wealth of Rust tutorials for microcontrollers and I bought an ESP32-C3-DevKit-RUST-1 for another tutorial and spent some time with my favorite Pi Pico and a newly-acquired Debug Probe.