diff --git a/README.md b/README.md
index a2eaa27..e764f68 100644
--- a/README.md
+++ b/README.md
@@ -42,22 +42,27 @@ Keyboard based on standard teensy "Keypad" library for button scanning, standard
   - LED flashing = Caps Lock activated
   - LED on = Gui key lock activated
 
-## Build environment
+## Build environment TeensyLC
+C/C++, Teensy arduino framework
 
-- Platformio
-  - env: teensylc
-  - platform: teensy
-  - board: teensylc
-  - framework: arduino
+- Platformio (platformio.ini)
 - Flashing via Teensy USB bootloader
   - Pressing boot button on teensy
   - Pressing all four corners on the keyboard
 
+## Build environment rp2040 Zero
+Rust embedded, rp2040 HAL
+
+- Cargo (cargo.toml)
+- Flashing via rp2040 USB bootloader
+  - Pressing reset/boot button on rp2040 Zero board
+  - Pressing all four corners on the keyboard
+
 ## Hardware
 
 [Schematics](build/cmdr_mainboard_v1.pdf)
 
-- 1x TeensyLC MCU
+- 1x TeensyLC alt 1x rp2040 Zero
 - 36x Cherry MX compatible switches
 - 6x Kailh Choc low profile switches
 - 42x 1N4148 diodes