From af115a1b706f88a381875be3e617c01b7ffa8636 Mon Sep 17 00:00:00 2001
From: bigalex <bigalex@gmx.de>
Date: Sat, 6 Jun 2020 00:59:34 +0200
Subject: [PATCH] provide PWM control for motors

---
 src/app_httpd.cpp           | 12 +++++-------
 src/esp32-cam-webserver.cpp | 23 ++++++++++++++---------
 src/robot_pins.h            | 16 +++++++++++-----
 3 files changed, 30 insertions(+), 21 deletions(-)

diff --git a/src/app_httpd.cpp b/src/app_httpd.cpp
index 308b169..741e394 100644
--- a/src/app_httpd.cpp
+++ b/src/app_httpd.cpp
@@ -446,14 +446,12 @@ void startCameraServer(){
 }
 
 
-// set motor directions and toggle motors on/off
-// TODO: control motor speed with PWM
+// set motor directions and speed 
 // TODO: fix bad SoC, this routine has nothing to do with the web server
 void updateMotors(){
-    // motor is switched on if the speed is >0.5 or <-0.5, else motor off
-    abs(current_speed_left)>0.5 ? digitalWrite(MOTOR_L_PWM, HIGH) : digitalWrite(MOTOR_L_PWM, LOW);
-    abs(current_speed_right)>0.5 ? digitalWrite(MOTOR_R_PWM, HIGH) : digitalWrite(MOTOR_R_PWM, LOW);
+    ledcWrite(MOTOR_L_PWM_CHAN, abs(current_speed_left)*1023);
+    ledcWrite(MOTOR_R_PWM_CHAN, abs(current_speed_right)*1023);
     // directions depends on whether speed is negative or positive
-    current_speed_left > 0 ? digitalWrite(MOTOR_L_DIR, HIGH) : digitalWrite(MOTOR_L_DIR, LOW);
-    current_speed_right > 0 ? digitalWrite(MOTOR_R_DIR, HIGH) : digitalWrite(MOTOR_R_DIR, LOW);
+    current_speed_left > 0 ? digitalWrite(MOTOR_L_DIR_PIN, HIGH) : digitalWrite(MOTOR_L_DIR_PIN, LOW);
+    current_speed_right > 0 ? digitalWrite(MOTOR_R_DIR_PIN, HIGH) : digitalWrite(MOTOR_R_DIR_PIN, LOW);
 }
diff --git a/src/esp32-cam-webserver.cpp b/src/esp32-cam-webserver.cpp
index 631d3f3..3c9d770 100644
--- a/src/esp32-cam-webserver.cpp
+++ b/src/esp32-cam-webserver.cpp
@@ -60,12 +60,14 @@ char myVer[] PROGMEM = __DATE__ " @ " __TIME__;
   int lampVal = -1; // disable Lamp
 #endif         
 int lampChannel = 7;     // a free PWM channel (some channels used by camera)
+                        // according to https://esp32.com/viewtopic.php?t=11379 those are channel 1 and 2
 const int pwmfreq = 50000;     // 50K pwm frequency
 const int pwmresolution = 9;   // duty cycle bit range
 // https://diarmuid.ie/blog/pwm-exponential-led-fading-on-arduino-or-other-platforms
 const int pwmIntervals = 100;  // The number of Steps between the output being on and off
 float lampR;                   // The R value in the PWM graph equation (calculated in setup)
 
+
 void startCameraServer();
 void flashLED(int flashtime);
 
@@ -154,15 +156,18 @@ void setup() {
 #endif
 
   // Mötör init
-  pinMode(MOTOR_L_PWM, OUTPUT);
-  digitalWrite(MOTOR_L_PWM, LOW); //off
-  pinMode(MOTOR_R_PWM, OUTPUT);
-  digitalWrite(MOTOR_R_PWM, LOW); //off
-  pinMode(MOTOR_L_DIR, OUTPUT);
-  digitalWrite(MOTOR_L_DIR, LOW); 
-  pinMode(MOTOR_R_DIR, OUTPUT);
-  digitalWrite(MOTOR_R_DIR, LOW); 
-
+  pinMode(MOTOR_L_PWM_PIN, OUTPUT);
+  ledcSetup(MOTOR_L_PWM_CHAN, MOTOR_PWM_FREQ_HZ, MOTOR_PWM_RES_BIT);
+  ledcAttachPin(MOTOR_L_PWM_PIN, MOTOR_L_PWM_CHAN);
+  ledcWrite(MOTOR_L_PWM_CHAN, 0); //off
+  pinMode(MOTOR_R_PWM_PIN, OUTPUT);
+  ledcSetup(MOTOR_R_PWM_CHAN, MOTOR_PWM_FREQ_HZ, MOTOR_PWM_RES_BIT);
+  ledcAttachPin(MOTOR_R_PWM_PIN, MOTOR_R_PWM_CHAN);
+  ledcWrite(MOTOR_R_PWM_CHAN, 0); //off
+  pinMode(MOTOR_L_DIR_PIN, OUTPUT);
+  digitalWrite(MOTOR_L_DIR_PIN, LOW); 
+  pinMode(MOTOR_R_DIR_PIN, OUTPUT);
+  digitalWrite(MOTOR_R_DIR_PIN, LOW); 
 
   // Feedback that hardware init is complete and we are now attempting to connect
   Serial.println("");
diff --git a/src/robot_pins.h b/src/robot_pins.h
index c9451be..1448161 100644
--- a/src/robot_pins.h
+++ b/src/robot_pins.h
@@ -1,4 +1,4 @@
-// Pin definitions for robot peripherals (actuators, LEDs, ...)
+// Pin and PWM definitions for robot peripherals (actuators, LEDs, ...)
 
 // TB6612FNG with 
 // GPIO 12 - PWM A left motor
@@ -6,8 +6,14 @@
 // GPIO 14 - DIR A 
 // GPIO 15 - DIR B
 
-#define MOTOR_L_PWM  12
-#define MOTOR_R_PWM  13
-#define MOTOR_L_DIR  14
-#define MOTOR_R_DIR  15
+#define MOTOR_L_PWM_PIN  12
+#define MOTOR_R_PWM_PIN  13
+#define MOTOR_L_DIR_PIN  14
+#define MOTOR_R_DIR_PIN  15
 
+#define MOTOR_L_PWM_CHAN 3
+#define MOTOR_R_PWM_CHAN 4
+// PWM resolution
+#define MOTOR_PWM_RES_BIT 10
+// PWM frequency
+#define MOTOR_PWM_FREQ_HZ 10000