We have ported our BASIC compiler for ARM to the Seeed XIAO SAMD21, RP2040 and NRF52840 boards. That BASIC has a set of runtime routines that are resident on the ARM to handle floating point, string, printf type functions and of course program download. That runtime is written in C.
And that C is compiled with gnuarm’s arm-none-eabi-gcc. To launch that compiler we use a home grown development environment called MakeItC that is written in Tcl. It is a very light weight set of routines totalling less than 2 MB ( NOT GB ) and runs on WIndows, Linux or Rasberry Pi. It includes an automated process to chase down compile and link all #include’d header files looking for .c or .cpp files to compile or .o files to link in.
All running on bare metal. Give it a try, we’d love feedback – even negative.
If I can scrounge up a modern Mac I’ll port it there too.
https://www.coridium.us/coridium/blog/the-big-release
One of our BASIC examples treats BLE as another serial port and can communicate with nRF Connect app on your phone.
Oh yeah, downloads are FREE.
GNUarm gcc using the MakeItC now supports the XIAO nRF54L15
“Light C” via the same MakeItC compiler,
with firmware runtime support for the complex stuff (printf, strings, flash write, etc.) so you’re not fighting a bare-metal build from scratch.
The XIAO nRF54L15 now boots, runs console I/O, GPIO, and onboard flash storage normally under this. Flashing is via the board’s onboard SWD probe
A factory-fresh board may report a flash error the very first time (known APPROTECT unlock quirk, not a bad board) — just retry once.
Also a BASIC compiler is also available. ARMbasic is a small, free toolchain for these boards — write in BASIC (compiled on your PC, not interpreted) and downloaded via serial link, no bootloader mode to enter.
Known limitation: Bluetooth LE isn’t working yet on this chip — the SoftDevice boots and advertises, but real BLE connectivity has an open
bug we’re actively chasing (with Nordic’s own support team involved). Everything else on the board works normally. Will update here once it’s resolved.
Free download at https://coridium.us.