feat(firmware): scaffold setup

Signed-off-by: Mumtahin Farabi <[email protected]>

1 files changed, 19 insertions, 0 deletions

diff --git a/firmware/boards/walter_esp32s3_procpu.overlay b/firmware/boards/walter_esp32s3_procpu.overlay
new file mode 100644
index 0000000..e500c05
--- /dev/null
+++ b/firmware/boards/walter_esp32s3_procpu.overlay
@@ -0,0 +1,19 @@
+/*
+ * Walter-specific application-level DT additions.
+ *
+ * Walter has a MOSFET on GPIO0 (active-low) that gates the on-board 3.3V
+ * output rail. The rail is OFF at reset; any external sensor wired to V3.3
+ * is unpowered until something asserts this GPIO. Modeled as a regulator-fixed
+ * with regulator-boot-on so Zephyr's regulator framework enables it during
+ * kernel init, before driver init runs.
+ */
+
+/ {
+	v3_3_regulator: v3_3-regulator {
+		compatible = "regulator-fixed";
+		regulator-name = "walter-3v3-output";
+		enable-gpios = <&gpio0 0 GPIO_ACTIVE_LOW>;
+		regulator-boot-on;
+		regulator-always-on;
+	};
+};