diff --git a/.gitignore b/.gitignore
index fb133f3a..e0ce0887 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,3 +7,4 @@ __pycache__
 78e43b91-b6a2-4e0a-99c2-3f6f74828063_ExportBlock-935e0d48-7286-4b74-aa60-ccd18217ac01
 node_modules/
 CLAUDE.md
+.build/
diff --git a/.husky/commit-msg b/.husky/commit-msg
index f6f2ce3f..9dc7802a 100644
--- a/.husky/commit-msg
+++ b/.husky/commit-msg
@@ -1,2 +1,6 @@
 #!/usr/bin/env sh
+if [ ! -d node_modules ]; then
+	echo "Error: node_modules is missing. Run 'make setup' or 'npm install' first."
+	exit 1
+fi
 npx --no-install commitlint --edit "$1"
diff --git a/.husky/pre-commit b/.husky/pre-commit
index 1d606c6e..64edfee0 100644
--- a/.husky/pre-commit
+++ b/.husky/pre-commit
@@ -1,2 +1,6 @@
 #!/usr/bin/env sh
+if [ ! -d node_modules ]; then
+	echo "Error: node_modules is missing. Run 'make setup' or 'npm install' first."
+	exit 1
+fi
 npx --no-install validate-branch-name && npx --no-install git-precommit-checks && npx --no-install lint-staged
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 53d74824..f3bc0a18 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -92,6 +92,8 @@ test(mcp23009e): Add mock scenarios for mcp23009e driver.
 5. Commit — the git hooks will automatically check your commit message and run ruff on staged files
 6. Push your branch and open a Pull Request
 
+If git hooks fail because `node_modules/` is missing (for example on a fresh clone or after `make deepclean`), run `make setup` or `npm install` before committing.
+
 ## Continuous Integration
 
 All pull requests must pass these checks:
@@ -122,6 +124,26 @@ make bump PART=minor   # minor: v1.0.1 → v1.1.0
 make bump PART=major   # major: v1.1.0 → v2.0.0
 ```
 
+## Firmware build and deploy
+
+The drivers are "frozen" into the MicroPython firmware for the STeaMi board. The Makefile automates cloning, building, and flashing:
+
+```bash
+make firmware       # Clone micropython-steami (if needed), link local drivers, build
+make firmware-update # Refresh the MicroPython clone and board-specific submodules
+make deploy         # Flash firmware via OpenOCD
+make run SCRIPT=lib/steami_config/examples/show_config.py      # Run with live output
+make deploy-script SCRIPT=lib/.../calibrate_magnetometer.py    # Deploy as main.py for autonomous use
+make run-main       # Re-execute the deployed main.py
+make firmware-clean # Clean firmware build artifacts
+```
+
+The firmware source is cloned into `.build/micropython-steami/` (gitignored). A symbolic link replaces the submodule `lib/micropython-steami-lib` with your local working directory, so the firmware always includes your latest changes — even uncommitted ones.
+
+Use `make firmware` for normal rebuilds from the existing local clone. Use `make firmware-update` only when you want to refresh the `micropython-steami` checkout itself or resync the board-specific submodules before rebuilding.
+
+**Requirements**: `arm-none-eabi-gcc` toolchain, OpenOCD for flashing, and `mpremote` for running scripts on the board.
+
 ## Notes
 
 * Keep implementations simple and readable
diff --git a/Makefile b/Makefile
index 9f06d607..69fed4c7 100644
--- a/Makefile
+++ b/Makefile
@@ -79,6 +79,61 @@ ci: lint test test-examples ## Run all CI checks (lint + tests + examples)
 .PHONY: build
 build: lint test ## Build (lint + test)
 
+# --- Firmware ---
+
+$(MPY_DIR):
+	@echo "Cloning micropython-steami into $(CURDIR)/$(MPY_DIR)..."
+	@mkdir -p $(dir $(CURDIR)/$(MPY_DIR))
+	git clone --branch $(MICROPYTHON_BRANCH) $(MICROPYTHON_REPO) $(CURDIR)/$(MPY_DIR)
+	cd $(CURDIR)/$(MPY_DIR)/ports/stm32 && $(MAKE) BOARD=$(BOARD) submodules
+
+.PHONY: firmware
+firmware: $(MPY_DIR) ## Build MicroPython firmware with current drivers
+	@echo "Linking local drivers..."
+	rm -rf $(CURDIR)/$(MPY_DIR)/lib/micropython-steami-lib
+	ln -s $(CURDIR) $(CURDIR)/$(MPY_DIR)/lib/micropython-steami-lib
+	@echo "Building firmware for $(BOARD)..."
+	cd $(CURDIR)/$(MPY_DIR)/ports/stm32 && $(MAKE) BOARD=$(BOARD)
+	@echo "Firmware ready: $(CURDIR)/$(MPY_DIR)/ports/stm32/build-$(BOARD)/firmware.hex"
+
+.PHONY: firmware-update
+firmware-update: $(MPY_DIR) ## Update the MicroPython clone and board-specific submodules
+	@echo "Updating micropython-steami..."
+	rm -rf $(CURDIR)/$(MPY_DIR)/lib/micropython-steami-lib
+	cd $(CURDIR)/$(MPY_DIR) && git fetch origin && git checkout $(MICROPYTHON_BRANCH) && git checkout -- lib/micropython-steami-lib && git pull --ff-only
+	@echo "Updating required submodules for $(BOARD)..."
+	cd $(CURDIR)/$(MPY_DIR)/ports/stm32 && $(MAKE) BOARD=$(BOARD) submodules
+
+.PHONY: deploy
+deploy: $(MPY_DIR) ## Flash firmware to the board via OpenOCD
+	cd $(CURDIR)/$(MPY_DIR)/ports/stm32 && $(MAKE) BOARD=$(BOARD) deploy-openocd
+
+.PHONY: run
+run: ## Run a script on the board with live output (SCRIPT=path/to/file.py)
+	@if [ -z "$(SCRIPT)" ]; then \
+		echo "Error: SCRIPT is required. Usage: make run SCRIPT=lib/.../example.py"; exit 1; \
+	fi
+	mpremote connect $(PORT) run $(SCRIPT)
+
+.PHONY: deploy-script
+deploy-script: ## Deploy a script as main.py for autonomous execution (SCRIPT=path/to/file.py)
+	@if [ -z "$(SCRIPT)" ]; then \
+		echo "Error: SCRIPT is required. Usage: make deploy-script SCRIPT=lib/.../example.py"; exit 1; \
+	fi
+	mpremote connect $(PORT) cp $(SCRIPT) :main.py
+	mpremote connect $(PORT) reset
+	@echo "Script deployed as main.py and board reset."
+
+.PHONY: run-main
+run-main: ## Re-execute main.py on the board and capture output
+	mpremote connect $(PORT) exec "exec(open('/flash/main.py').read())"
+
+.PHONY: firmware-clean
+firmware-clean: ## Clean firmware build artifacts
+	@if [ -d "$(MPY_DIR)/ports/stm32" ]; then \
+		cd $(MPY_DIR)/ports/stm32 && $(MAKE) BOARD=$(BOARD) clean; \
+	fi
+
 # --- Hardware ---
 
 .PHONY: repl
@@ -141,8 +196,9 @@ clean: ## Remove build artifacts and caches
 	find . -type d -name .mypy_cache -exec rm -rf {} + 2>/dev/null || true
 
 .PHONY: deepclean
-deepclean: clean ## Remove everything including node_modules
+deepclean: clean ## Remove everything including node_modules and firmware
 	rm -rf node_modules
+	@if [ -d "$(BUILD_DIR)" ]; then rm -rf "$(BUILD_DIR)"; fi
 
 .PHONY: help
 help: ## Show this help
@@ -159,4 +215,4 @@ printvars:
 # Affiche toutes les cibles disponibles dans le Makefile
 .PHONY: list
 list:
-	@LC_ALL=C $(MAKE) -pRrq -f $(firstword $(MAKEFILE_LIST)) : 2>/dev/null | awk -v RS= -F: '/(^|\n)# Files(\n|$$)/,/(^|\n)# Finished Make data base/ {if ($$1 !~ "^[#.]") {print $$1}}' | sort | grep -E -v -e '^[^[:alnum:]]' -e '^$@$$'
\ No newline at end of file
+	@LC_ALL=C $(MAKE) -pRrq -f $(firstword $(MAKEFILE_LIST)) : 2>/dev/null | awk -v RS= -F: '/(^|\n)# Files(\n|$$)/,/(^|\n)# Finished Make data base/ {if ($$1 !~ "^[#.]") {print $$1}}' | sort | grep -E -v -e '^[^[:alnum:]]' -e '^$@$$'
diff --git a/env.mk b/env.mk
index 61b7103d..88de225d 100644
--- a/env.mk
+++ b/env.mk
@@ -1,2 +1,9 @@
 export PATH := $(CURDIR)/node_modules/.bin:$(PATH)
 PORT ?= /dev/ttyACM0
+
+# Firmware build configuration
+MICROPYTHON_REPO ?= https://github.com/steamicc/micropython-steami.git
+MICROPYTHON_BRANCH ?= stm32-steami-rev1d-final
+BOARD ?= STEAM32_WB55RG
+BUILD_DIR ?= .build
+MPY_DIR ?= $(BUILD_DIR)/micropython-steami