Merge pull request #320 from brentru/fix-servo-bug-esp32s2

Fix servo not working on ESP32-S2

library.properties

@@ -1,5 +1,5 @@
 name=Adafruit WipperSnapper
-version=1.0.0-beta.47
+version=1.0.0-beta.48
 author=Adafruit
 maintainer=Adafruit <[email protected]>
 sentence=Arduino client for Adafruit.io WipperSnapper

src/Wippersnapper.h

@@ -67,7 +67,7 @@
 #endif
 
 #define WS_VERSION                                                             \
-  "1.0.0-beta.47" ///< WipperSnapper app. version (semver-formatted)
+  "1.0.0-beta.48" ///< WipperSnapper app. version (semver-formatted)
 
 // Reserved Adafruit IO MQTT topics
 #define TOPIC_IO_THROTTLE "/throttle" ///< Adafruit IO Throttle MQTT Topic

src/components/ledc/drivers/ws_ledc_servo.cpp

@@ -62,7 +62,8 @@ void ws_ledc_servo::setLEDCDriver(ws_ledc *ledcManager) {
 uint8_t ws_ledc_servo::attach(int pin, int minPulseWidth, int maxPulseWidth,
                               int servoFreq) {
   // Attempt to attach a pin to ledc channel
-  uint8_t chan = _ledcMgr->attachPin((uint8_t)pin, (double)servoFreq);
+  uint8_t chan =
+      _ledcMgr->attachPin((uint8_t)pin, (double)servoFreq, LEDC_TIMER_WIDTH);
   if (chan == 255) // error!
     return chan;
   // configure the servo object and assign it to a pin
@@ -101,7 +102,6 @@ bool ws_ledc_servo::attached() { return _servo.Pin.isActive; }
 void ws_ledc_servo::writeMicroseconds(int value) {
   // are we attached to a pin?
   if (!attached()) {
-    Serial.println("NOT ATTACHED TO PIN!");
     return;
   }
 
@@ -111,12 +111,12 @@ void ws_ledc_servo::writeMicroseconds(int value) {
   if (value > _maxPulseWidth)
     value = _maxPulseWidth;
 
-  // formula from
+  // formula from ESP32Servo library
   // https://github.com/madhephaestus/ESP32Servo/blob/master/src/ESP32Servo.cpp
   // count = (pulse_high_width / (pulse_period/2**timer_width))
   // 50Hz servo =  20ms pulse_period
-  // count = pulse_high_width /((20000/65536))
-  uint32_t count = ((double)value / 0.30517578);
+  uint32_t count =
+      ((double)value / ((double)20000 / (double)pow(2, LEDC_TIMER_WIDTH)));
   _ledcMgr->setDuty(_servo.Pin.nbr, count);
 }
 #endif // ARDUINO_ARCH_ESP32

src/components/ledc/drivers/ws_ledc_servo.h

@@ -25,8 +25,13 @@
 #define MAX_PULSE_WIDTH 2400 ///< The longest pulse sent to a servo
 #define INVALID_SERVO 255    ///< Flag indicating an invalid servo index
 
-#define DEFAULT_SERVO_FREQ 50    ///< default servo frequency
-#define MAX_SERVOS MAX_LEDC_PWMS ///< Maximum number of servo instance
+#define DEFAULT_SERVO_FREQ 50 ///< default servo frequency
+#define LEDC_TIMER_WIDTH                                                       \
+  12 ///< timer width to request from LEDC manager component, in bits (NOTE:
+     ///< While ESP32x can go up to 16 bit timer width, ESP32-S2 does not work
+     ///< at this resolution. So, for the purposes of keeping this library
+     ///< compatible with multiple ESP32x platforms, the timer width has been
+     ///< scaled down to 10 bits and the calculation adjusted accordingly)
 
 /** Defines a servo attached to a pin */
 typedef struct {

src/components/ledc/ws_ledc.cpp

@@ -46,20 +46,21 @@ ws_ledc::~ws_ledc() {
 /*!
     @brief  Allocates a timer + channel for a pin and attaches it.
     @param  pin  Desired GPIO pin number.
-    @param  freq Desired timer frequency, in Hz.
+    @param  freq Desired LEDC timer frequency, in Hz.
+    @param  resolution Desired LEDC timer resolution, in bits.
     @return The channel number if the pin was successfully attached,
             otherwise 255.
 */
 /**************************************************************************/
-uint8_t ws_ledc::attachPin(uint8_t pin, double freq) {
+uint8_t ws_ledc::attachPin(uint8_t pin, double freq, uint8_t resolution) {
   // have we already attached this pin?
   for (int i = 0; i < MAX_LEDC_PWMS; i++) {
     if (_ledcPins[i].pin == pin)
       return 255;
   }
 
   // allocate chanel
-  uint8_t chanNum = _allocateChannel(freq);
+  uint8_t chanNum = _allocateChannel(freq, resolution);
   if (chanNum == 255)
     return chanNum;
 
@@ -96,12 +97,13 @@ void ws_ledc::detachPin(uint8_t pin) {
 /**************************************************************************/
 /*!
     @brief  Allocates a channel and timer.
-    @param  freq Desired timer frequency, in Hz.
+    @param  freq Desired LEDC timer frequency, in Hz.
+    @param  resolution Desired LEDC timer resolution, in bits.
     @return The channel number if the timer was successfully initialized,
             otherwise 255.
 */
 /**************************************************************************/
-uint8_t ws_ledc::_allocateChannel(double freq) {
+uint8_t ws_ledc::_allocateChannel(double freq, uint8_t resolution) {
   // attempt to allocate an inactive channel
   uint8_t chanNum = 255;
   for (int i = 0; i < MAX_LEDC_PWMS; i++) {
@@ -116,7 +118,7 @@ uint8_t ws_ledc::_allocateChannel(double freq) {
     return 255;
 
   // attempt to set up a ledc_timer on the free channel
-  double rc = ledcSetup(uint8_t(chanNum), freq, 16);
+  double rc = ledcSetup(uint8_t(chanNum), freq, resolution);
   if (rc == 0)
     return 255;
 

src/components/ledc/ws_ledc.h

@@ -24,8 +24,6 @@
 #define MAX_LEDC_PWMS                                                          \
   16 ///< maximum # of LEDC channels (see: LEDC Chan to Group/Channel/Timer
      ///< Mapping)
-#define LEDC_RESOLUTION 10 ///< max LEDC resolution
-#define MAX_TIMER_WIDTH 20 ///< max LEDC esp32 timer width
 
 /** Defines a pin attached to an active LEDC timer group */
 typedef struct {
@@ -51,12 +49,12 @@ class ws_ledc {
 public:
   ws_ledc();
   ~ws_ledc();
-  uint8_t attachPin(uint8_t pin, double freq);
+  uint8_t attachPin(uint8_t pin, double freq, uint8_t resolution);
   void detachPin(uint8_t pin);
   void setDuty(uint8_t pin, uint32_t duty);
 
 private:
-  uint8_t _allocateChannel(double freq);
+  uint8_t _allocateChannel(double freq, uint8_t resolution);
   ledcPin_t _ledcPins[MAX_LEDC_PWMS]; ///< Pool of usable LEDC pins
 };
 extern Wippersnapper WS;