Try using installable Preferences library

.github/workflows/build.yml

@@ -29,6 +29,13 @@ jobs:
       run: sed -i 's/^#define WIFI_ENABLED 1$/#define WIFI_ENABLED 0/' flix/flix.ino && make
     - name: Check c_cpp_properties.json
       run: tools/check_c_cpp_properties.py
+    - name: Build for Black Pill F411CE (STM32)
+      run: |
+        arduino-cli config set board_manager.additional_urls https://github.com/stm32duino/BoardManagerFiles/raw/main/package_stmicroelectronics_index.json
+        arduino-cli core install STMicroelectronics:stm32
+        arduino-cli board listall STMicroelectronics:stm32
+        arduino-cli lib install "Preferences"
+        make BOARD=STMicroelectronics:stm32:GenF4:pnum=BLACKPILL_F411CE
 
   build_macos:
     runs-on: macos-latest

flix/motors.ino

@@ -25,13 +25,15 @@ const int MOTOR_FRONT_LEFT = 3;
 
 void setupMotors() {
 	print("Setup Motors\n");
-
-	// configure pins
+#ifdef ESP32
 	ledcAttach(MOTOR_0_PIN, PWM_FREQUENCY, PWM_RESOLUTION);
 	ledcAttach(MOTOR_1_PIN, PWM_FREQUENCY, PWM_RESOLUTION);
 	ledcAttach(MOTOR_2_PIN, PWM_FREQUENCY, PWM_RESOLUTION);
 	ledcAttach(MOTOR_3_PIN, PWM_FREQUENCY, PWM_RESOLUTION);
-
+#else
+	analogWriteResolution(PWM_RESOLUTION);
+	analogWriteFrequency(PWM_FREQUENCY);
+#endif
 	sendMotors();
 	print("Motors initialized\n");
 }
@@ -45,10 +47,10 @@ int getDutyCycle(float value) {
 }
 
 void sendMotors() {
-	ledcWrite(MOTOR_0_PIN, getDutyCycle(motors[0]));
-	ledcWrite(MOTOR_1_PIN, getDutyCycle(motors[1]));
-	ledcWrite(MOTOR_2_PIN, getDutyCycle(motors[2]));
-	ledcWrite(MOTOR_3_PIN, getDutyCycle(motors[3]));
+	analogWrite(MOTOR_0_PIN, getDutyCycle(motors[0]));
+	analogWrite(MOTOR_1_PIN, getDutyCycle(motors[1]));
+	analogWrite(MOTOR_2_PIN, getDutyCycle(motors[2]));
+	analogWrite(MOTOR_3_PIN, getDutyCycle(motors[3]));
 }
 
 bool motorsActive() {

flix/util.h

@@ -6,8 +6,10 @@
 #pragma once
 
 #include <math.h>
+#ifdef ESP32
 #include <soc/soc.h>
 #include <soc/rtc_cntl_reg.h>
+#endif
 
 const float ONE_G = 9.80665;
 extern float t;
@@ -37,7 +39,9 @@ float wrapAngle(float angle) {
 
 // Disable reset on low voltage
 void disableBrownOut() {
+#ifdef ESP32
 	REG_CLR_BIT(RTC_CNTL_BROWN_OUT_REG, RTC_CNTL_BROWN_OUT_ENA);
+#endif
 }
 
 // Trim and split string by spaces