Merge pull request #8 from EmbeddedMan/master

Add support for PIC32 architecture (fixes issue #7)

3 files changed, 207 insertions, 26 deletions

diff --git a/AFMotor.cpp b/AFMotor.cpp
index 8ac0c08..c1f6482 100644
--- a/AFMotor.cpp
+++ b/AFMotor.cpp
@@ -4,11 +4,14 @@
 
 
 #if (ARDUINO >= 100)
- #include "Arduino.h"
+  #include "Arduino.h"
 #else
- #include <avr/io.h>
- #include "WProgram.h"
+  #if defined(__AVR__)
+    #include <avr/io.h>
+  #endif
+  #include "WProgram.h"
 #endif
+
 #include "AFMotor.h"
 
 
@@ -22,6 +25,7 @@ uint8_t microstepcurve[] = {0, 25, 50, 74, 98, 120, 141, 162, 180, 197, 212, 225
 #endif
 
 AFMotorController::AFMotorController(void) {
+    TimerInitalized = false;
 }
 
 void AFMotorController::enable(void) {
@@ -75,7 +79,6 @@ void AFMotorController::latch_tx(void) {
 
 static AFMotorController MC;
 
-
 /******************************************
                MOTORS
 ******************************************/
@@ -94,10 +97,47 @@ inline void initPWM1(uint8_t freq) {
     TCCR1A |= _BV(COM1A1) | _BV(WGM10); // fast PWM, turn on oc1a
     TCCR1B = (freq & 0x7) | _BV(WGM12);
     OCR1A = 0;
+#elif defined(__PIC32MX__)
+    #if defined(PIC32_USE_PIN9_FOR_M1_PWM)
+        // Make sure that pin 11 is an input, since we have tied together 9 and 11
+        pinMode(9, OUTPUT);
+        pinMode(11, INPUT);
+        if (!MC.TimerInitalized)
+        {   // Set up Timer2 for 80MHz counting fro 0 to 256
+            T2CON = 0x8000 | ((freq & 0x07) << 4); // ON=1, FRZ=0, SIDL=0, TGATE=0, TCKPS=<freq>, T32=0, TCS=0; // ON=1, FRZ=0, SIDL=0, TGATE=0, TCKPS=0, T32=0, TCS=0
+            TMR2 = 0x0000;
+            PR2 = 0x0100;
+            MC.TimerInitalized = true;
+        }
+         // Setup OC4 (pin 9) in PWM mode, with Timer2 as timebase
+        OC4CON = 0x8006;    // OC32 = 0, OCTSEL=0, OCM=6
+        OC4RS = 0x0000;
+        OC4R = 0x0000;
+    #elif defined(PIC32_USE_PIN10_FOR_M1_PWM)
+        // Make sure that pin 11 is an input, since we have tied together 9 and 11
+        pinMode(10, OUTPUT);
+        pinMode(11, INPUT);
+        if (!MC.TimerInitalized)
+        {   // Set up Timer2 for 80MHz counting fro 0 to 256
+            T2CON = 0x8000 | ((freq & 0x07) << 4); // ON=1, FRZ=0, SIDL=0, TGATE=0, TCKPS=<freq>, T32=0, TCS=0; // ON=1, FRZ=0, SIDL=0, TGATE=0, TCKPS=0, T32=0, TCS=0
+            TMR2 = 0x0000;
+            PR2 = 0x0100;
+            MC.TimerInitalized = true;
+        }
+         // Setup OC5 (pin 10) in PWM mode, with Timer2 as timebase
+        OC5CON = 0x8006;    // OC32 = 0, OCTSEL=0, OCM=6
+        OC5RS = 0x0000;
+        OC5R = 0x0000;
+    #else
+        // If we are not using PWM for pin 11, then just do digital
+        digitalWrite(11, LOW);
+    #endif
 #else
    #error "This chip is not supported!"
 #endif
-    pinMode(11, OUTPUT);
+    #if !defined(PIC32_USE_PIN9_FOR_M1_PWM) && !defined(PIC32_USE_PIN10_FOR_M1_PWM)
+        pinMode(11, OUTPUT);
+    #endif
 }
 
 inline void setPWM1(uint8_t s) {
@@ -111,6 +151,24 @@ inline void setPWM1(uint8_t s) {
 #elif defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
     // on arduino mega, pin 11 is now PB5 (OC1A)
     OCR1A = s;
+#elif defined(__PIC32MX__)
+    #if defined(PIC32_USE_PIN9_FOR_M1_PWM)
+        // Set the OC4 (pin 9) PMW duty cycle from 0 to 255
+        OC4RS = s;
+    #elif defined(PIC32_USE_PIN10_FOR_M1_PWM)
+        // Set the OC5 (pin 10) PMW duty cycle from 0 to 255
+        OC5RS = s;
+    #else
+        // If we are not doing PWM output for M1, then just use on/off
+        if (s > 127)
+        {
+            digitalWrite(11, HIGH);
+        }
+        else
+        {
+            digitalWrite(11, LOW);
+        }
+    #endif
 #else
    #error "This chip is not supported!"
 #endif
@@ -131,6 +189,18 @@ inline void initPWM2(uint8_t freq) {
     TCCR3A |= _BV(COM1C1) | _BV(WGM10); // fast PWM, turn on oc3c
     TCCR3B = (freq & 0x7) | _BV(WGM12);
     OCR3C = 0;
+#elif defined(__PIC32MX__)
+    if (!MC.TimerInitalized)
+    {   // Set up Timer2 for 80MHz counting fro 0 to 256
+        T2CON = 0x8000 | ((freq & 0x07) << 4); // ON=1, FRZ=0, SIDL=0, TGATE=0, TCKPS=<freq>, T32=0, TCS=0; // ON=1, FRZ=0, SIDL=0, TGATE=0, TCKPS=0, T32=0, TCS=0
+        TMR2 = 0x0000;
+        PR2 = 0x0100;
+        MC.TimerInitalized = true;
+    }
+    // Setup OC1 (pin3) in PWM mode, with Timer2 as timebase
+    OC1CON = 0x8006;    // OC32 = 0, OCTSEL=0, OCM=6
+    OC1RS = 0x0000;
+    OC1R = 0x0000;
 #else
    #error "This chip is not supported!"
 #endif
@@ -149,6 +219,9 @@ inline void setPWM2(uint8_t s) {
 #elif defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
     // on arduino mega, pin 11 is now PB5 (OC1A)
     OCR3C = s;
+#elif defined(__PIC32MX__)
+    // Set the OC1 (pin3) PMW duty cycle from 0 to 255
+    OC1RS = s;
 #else
    #error "This chip is not supported!"
 #endif
@@ -170,6 +243,18 @@ inline void initPWM3(uint8_t freq) {
     TCCR4B = (freq & 0x7) | _BV(WGM12);
     //TCCR4B = 1 | _BV(WGM12);
     OCR4A = 0;
+#elif defined(__PIC32MX__)
+    if (!MC.TimerInitalized)
+    {   // Set up Timer2 for 80MHz counting fro 0 to 256
+        T2CON = 0x8000 | ((freq & 0x07) << 4); // ON=1, FRZ=0, SIDL=0, TGATE=0, TCKPS=<freq>, T32=0, TCS=0; // ON=1, FRZ=0, SIDL=0, TGATE=0, TCKPS=0, T32=0, TCS=0
+        TMR2 = 0x0000;
+        PR2 = 0x0100;
+        MC.TimerInitalized = true;
+    }
+    // Setup OC3 (pin 6) in PWM mode, with Timer2 as timebase
+    OC3CON = 0x8006;    // OC32 = 0, OCTSEL=0, OCM=6
+    OC3RS = 0x0000;
+    OC3R = 0x0000;
 #else
    #error "This chip is not supported!"
 #endif
@@ -187,6 +272,9 @@ inline void setPWM3(uint8_t s) {
 #elif defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
     // on arduino mega, pin 6 is now PH3 (OC4A)
     OCR4A = s;
+#elif defined(__PIC32MX__)
+    // Set the OC3 (pin 6) PMW duty cycle from 0 to 255
+    OC3RS = s;
 #else
    #error "This chip is not supported!"
 #endif
@@ -210,6 +298,18 @@ inline void initPWM4(uint8_t freq) {
     TCCR3B = (freq & 0x7) | _BV(WGM12);
     //TCCR4B = 1 | _BV(WGM12);
     OCR3A = 0;
+#elif defined(__PIC32MX__)
+    if (!MC.TimerInitalized)
+    {   // Set up Timer2 for 80MHz counting fro 0 to 256
+        T2CON = 0x8000 | ((freq & 0x07) << 4); // ON=1, FRZ=0, SIDL=0, TGATE=0, TCKPS=<freq>, T32=0, TCS=0; // ON=1, FRZ=0, SIDL=0, TGATE=0, TCKPS=0, T32=0, TCS=0
+        TMR2 = 0x0000;
+        PR2 = 0x0100;
+        MC.TimerInitalized = true;
+    }
+    // Setup OC2 (pin 5) in PWM mode, with Timer2 as timebase
+    OC2CON = 0x8006;    // OC32 = 0, OCTSEL=0, OCM=6
+    OC2RS = 0x0000;
+    OC2R = 0x0000;
 #else
    #error "This chip is not supported!"
 #endif
@@ -227,6 +327,9 @@ inline void setPWM4(uint8_t s) {
 #elif defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
     // on arduino mega, pin 6 is now PH3 (OC4A)
     OCR3A = s;
+#elif defined(__PIC32MX__)
+    // Set the OC2 (pin 5) PMW duty cycle from 0 to 255
+    OC2RS = s;
 #else
    #error "This chip is not supported!"
 #endif
@@ -289,7 +392,7 @@ void AF_DCMotor::run(uint8_t cmd) {
     MC.latch_tx();
     break;
   case RELEASE:
-    latch_state &= ~_BV(a);
+    latch_state &= ~_BV(a);     // A and B both low
     latch_state &= ~_BV(b); 
     MC.latch_tx();
     break;
@@ -332,8 +435,8 @@ AF_Stepper::AF_Stepper(uint16_t steps, uint8_t num) {
     digitalWrite(3, HIGH);
 
     // use PWM for microstepping support
-    initPWM1(MOTOR12_64KHZ);
-    initPWM2(MOTOR12_64KHZ);
+    initPWM1(STEPPER1_PWM_RATE);
+    initPWM2(STEPPER1_PWM_RATE);
     setPWM1(255);
     setPWM2(255);
 
@@ -350,8 +453,8 @@ AF_Stepper::AF_Stepper(uint16_t steps, uint8_t num) {
 
     // use PWM for microstepping support
     // use PWM for microstepping support
-    initPWM3(1);
-    initPWM4(1);
+    initPWM3(STEPPER2_PWM_RATE);
+    initPWM4(STEPPER2_PWM_RATE);
     setPWM3(255);
     setPWM4(255);
   }
diff --git a/AFMotor.h b/AFMotor.h
index 3b954a5..0362211 100644
--- a/AFMotor.h
+++ b/AFMotor.h
@@ -2,25 +2,99 @@
 // copyright Adafruit Industries LLC, 2009
 // this code is public domain, enjoy!
 
+/*
+ * Usage Notes:
+ * For PIC32, all features work properly with the following two exceptions:
+ *
+ * 1) Because the PIC32 only has 5 PWM outputs, and the AFMotor shield needs 6
+ *    to completely operate (for for motor outputs and two for RC servos), the
+ *    M1 motor output will not have PWM ability when used with a PIC32 board.
+ *    However, there is a very simple workaround. If you need to drive a stepper
+ *    or DC motor with PWM on motor output M1, you can use the PWM output on pin
+ *    9 or pin 10 (normally use for RC servo outputs on Arduino, not needed for 
+ *    RC servo outputs on PIC32) to drive the PWM input for M1 by simply putting
+ *    a jumber from pin 9 to pin 11 or pin 10 to pin 11. Then uncomment one of the
+ *    two #defines below to activate the PWM on either pin 9 or pin 10. You will
+ *    then have a fully functional microstepping for 2 stepper motors, or four
+ *    DC motor outputs with PWM.
+ *
+ * 2) There is a conflict between RC Servo outputs on pins 9 and pins 10 and 
+ *    the operation of DC motors and stepper motors as of 9/2012. This issue
+ *    will get fixed in future MPIDE releases, but at the present time it means
+ *    that the Motor Party example will NOT work properly. Any time you attach
+ *    an RC servo to pins 9 or pins 10, ALL PWM outputs on the whole board will
+ *    stop working. Thus no steppers or DC motors.
+ * 
+ */
+// <BPS> 09/15/2012 Modified for use with chipKIT boards
+
+
 #ifndef _AFMotor_h_
 #define _AFMotor_h_
 
 #include <inttypes.h>
-#include <avr/io.h>
-
-//#define MOTORDEBUG 1
-
-#define MICROSTEPS 16         // 8 or 16
-
-#define MOTOR12_64KHZ _BV(CS20)  // no prescale
-#define MOTOR12_8KHZ _BV(CS21)   // divide by 8
-#define MOTOR12_2KHZ _BV(CS21) | _BV(CS20) // divide by 32
-#define MOTOR12_1KHZ _BV(CS22)  // divide by 64
-
-#define MOTOR34_64KHZ _BV(CS00)  // no prescale
-#define MOTOR34_8KHZ _BV(CS01)   // divide by 8
-#define MOTOR34_1KHZ _BV(CS01) | _BV(CS00)  // divide by 64
+#if defined(__AVR__)
+    #include <avr/io.h>
+
+    //#define MOTORDEBUG 1
+
+    #define MICROSTEPS 16                       // 8 or 16
+
+    #define MOTOR12_64KHZ _BV(CS20)             // no prescale
+    #define MOTOR12_8KHZ _BV(CS21)              // divide by 8
+    #define MOTOR12_2KHZ _BV(CS21) | _BV(CS20)  // divide by 32
+    #define MOTOR12_1KHZ _BV(CS22)              // divide by 64
+
+    #define MOTOR34_64KHZ _BV(CS00)             // no prescale
+    #define MOTOR34_8KHZ _BV(CS01)              // divide by 8
+    #define MOTOR34_1KHZ _BV(CS01) | _BV(CS00)  // divide by 64
+    
+    #define DC_MOTOR_PWM_RATE   MOTOR34_8KHZ    // PWM rate for DC motors
+    #define STEPPER1_PWM_RATE   MOTOR12_64KHZ   // PWM rate for stepper 1
+    #define STEPPER2_PWM_RATE   MOTOR34_64KHZ   // PWM rate for stepper 2
+    
+#elif defined(__PIC32MX__)
+    //#define MOTORDEBUG 1
+    
+    // Uncomment the one of following lines if you have put a jumper from 
+    // either pin 9 to pin 11 or pin 10 to pin 11 on your Motor Shield.
+    // Either will enable PWM for M1
+    //#define PIC32_USE_PIN9_FOR_M1_PWM
+    //#define PIC32_USE_PIN10_FOR_M1_PWM
+
+    #define MICROSTEPS 16       // 8 or 16
+
+    // For PIC32 Timers, define prescale settings by PWM frequency
+    #define MOTOR12_312KHZ  0   // 1:1, actual frequency 312KHz
+    #define MOTOR12_156KHZ  1   // 1:2, actual frequency 156KHz
+    #define MOTOR12_64KHZ   2   // 1:4, actual frequency 78KHz
+    #define MOTOR12_39KHZ   3   // 1:8, acutal frequency 39KHz
+    #define MOTOR12_19KHZ   4   // 1:16, actual frequency 19KHz
+    #define MOTOR12_8KHZ    5   // 1:32, actual frequency 9.7KHz
+    #define MOTOR12_4_8KHZ  6   // 1:64, actual frequency 4.8KHz
+    #define MOTOR12_2KHZ    7   // 1:256, actual frequency 1.2KHz
+    #define MOTOR12_1KHZ    7   // 1:256, actual frequency 1.2KHz
+
+    #define MOTOR34_312KHZ  0   // 1:1, actual frequency 312KHz
+    #define MOTOR34_156KHZ  1   // 1:2, actual frequency 156KHz
+    #define MOTOR34_64KHZ   2   // 1:4, actual frequency 78KHz
+    #define MOTOR34_39KHZ   3   // 1:8, acutal frequency 39KHz
+    #define MOTOR34_19KHZ   4   // 1:16, actual frequency 19KHz
+    #define MOTOR34_8KHZ    5   // 1:32, actual frequency 9.7KHz
+    #define MOTOR34_4_8KHZ  6   // 1:64, actual frequency 4.8KHz
+    #define MOTOR34_2KHZ    7   // 1:256, actual frequency 1.2KHz
+    #define MOTOR34_1KHZ    7   // 1:256, actual frequency 1.2KHz
+    
+    // PWM rate for DC motors.
+    #define DC_MOTOR_PWM_RATE   MOTOR34_39KHZ
+    // Note: for PIC32, both of these must be set to the same value
+    // since there's only one timebase for all 4 PWM outputs
+    #define STEPPER1_PWM_RATE   MOTOR12_39KHZ
+    #define STEPPER2_PWM_RATE   MOTOR34_39KHZ
+    
+#endif
 
+// Bit positions in the 74HCT595 shift register output
 #define MOTOR1_A 2
 #define MOTOR1_B 3
 #define MOTOR2_A 1
@@ -30,11 +104,13 @@
 #define MOTOR3_A 5
 #define MOTOR3_B 7
 
+// Constants that the user passes in to the motor calls
 #define FORWARD 1
 #define BACKWARD 2
 #define BRAKE 3
 #define RELEASE 4
 
+// Constants that the user passes in to the stepper calls
 #define SINGLE 1
 #define DOUBLE 2
 #define INTERLEAVE 3
@@ -58,7 +134,7 @@
 #define SER_PORT PORTB
 */
 
-// Arduino pin names
+// Arduino pin names for interface to 74HCT595 latch
 #define MOTORLATCH 12
 #define MOTORCLK 4
 #define MOTORENABLE 7
@@ -71,12 +147,13 @@ class AFMotorController
     void enable(void);
     friend class AF_DCMotor;
     void latch_tx(void);
+    uint8_t TimerInitalized;
 };
 
 class AF_DCMotor
 {
  public:
-  AF_DCMotor(uint8_t motornum, uint8_t freq =  MOTOR34_8KHZ);
+  AF_DCMotor(uint8_t motornum, uint8_t freq = DC_MOTOR_PWM_RATE);
   void run(uint8_t);
   void setSpeed(uint8_t);
 
diff --git a/README.txt b/README.txt
index dfc5765..00cc0e9 100644
--- a/README.txt
+++ b/README.txt
@@ -1,4 +1,5 @@
 This is the August 12, 2009 Adafruit Motor shield firmware with basic Microstepping support. Works with all Arduinos and the Mega
+Updated in September 2012 for use on PIC32 architecture (chipKIT/MPIDE)
 
 For more information on the shield, please visit http://www.ladyada.net/make/mshield/