From 6d66e5759cfd5f35a8177a7d2b8f981b09be486f Mon Sep 17 00:00:00 2001
From: "Michael D. M. Dryden" <mdryden@chem.utoronto.ca>
Date: Sat, 27 Jun 2015 21:28:05 -0600
Subject: [PATCH] Implements #3, timers for stepping.

---
 asf/common/boards/user_board/init.c | 15 +++++--
 config/conf_board.h                 | 35 ++++++++-------
 main.c                              | 66 ++++++++++++++++++-----------
 3 files changed, 74 insertions(+), 42 deletions(-)

diff --git a/asf/common/boards/user_board/init.c b/asf/common/boards/user_board/init.c
index fcf6247..c62d779 100644
--- a/asf/common/boards/user_board/init.c
+++ b/asf/common/boards/user_board/init.c
@@ -26,11 +26,20 @@ void board_init(void)
     ioport_set_pin_dir(PIN_DIR, IOPORT_DIR_OUTPUT);
 
     ioport_set_pin_level(PIN_EN, 0);
-    ioport_set_pin_level(PIN_MS1, 1);
-    ioport_set_pin_level(PIN_MS2, 1);
-    ioport_set_pin_level(PIN_MS3, 0);
     ioport_set_pin_level(PIN_RST, 1);
     ioport_set_pin_level(PIN_SLP, 1);
     ioport_set_pin_level(PIN_DIR, 1);
+    
+    // 8x microstepping
+    ioport_set_pin_level(PIN_MS1, 1);
+    ioport_set_pin_level(PIN_MS2, 1);
+    ioport_set_pin_level(PIN_MS3, 0);
+    
+    ioport_set_pin_dir(PIN_ZMIN, IOPORT_DIR_INPUT);
+    ioport_set_pin_sense_mode(PIN_ZMIN, IOPORT_SENSE_FALLING);
+    
+    #ifdef PIN_ZMIN_PULLUP_ENABLED
+    ioport_set_pin_mode(PIN_ZMIN, IOPORT_MODE_PULLUP);
+    #endif // PIN_ZMIN_PULLUP_ENABLED
 
 }
diff --git a/config/conf_board.h b/config/conf_board.h
index b11107a..7dc97ca 100644
--- a/config/conf_board.h
+++ b/config/conf_board.h
@@ -1,20 +1,25 @@
-/**
- * \file
- *
- * \brief User board configuration template
- *
- */
-
 #ifndef CONF_BOARD_H
 #define CONF_BOARD_H
 
-#define PIN_EN      IOPORT_CREATE_PIN(PORTD, 2)
-#define PIN_MS1     IOPORT_CREATE_PIN(PORTD, 3)
-#define PIN_MS2     IOPORT_CREATE_PIN(PORTD, 4)
-#define PIN_MS3     IOPORT_CREATE_PIN(PORTD, 5)
-#define PIN_RST     IOPORT_CREATE_PIN(PORTD, 6)
-#define PIN_SLP     IOPORT_CREATE_PIN(PORTD, 7)
-#define PIN_STEP    IOPORT_CREATE_PIN(PORTB, 0)
-#define PIN_DIR     IOPORT_CREATE_PIN(PORTB, 1)
+#define PIN_EN          IOPORT_CREATE_PIN(PORTD, 2)
+#define PIN_MS1         IOPORT_CREATE_PIN(PORTD, 3)
+#define PIN_MS2         IOPORT_CREATE_PIN(PORTD, 4)
+#define PIN_MS3         IOPORT_CREATE_PIN(PORTD, 5)
+#define PIN_RST         IOPORT_CREATE_PIN(PORTD, 6)
+#define PIN_SLP         IOPORT_CREATE_PIN(PORTD, 7)
+#define PIN_STEP        IOPORT_CREATE_PIN(PORTB, 0)
+#define PIN_DIR         IOPORT_CREATE_PIN(PORTB, 1)
+
+// Endstop
+#define PIN_ZMIN        IOPORT_CREATE_PIN(PORTB, 2)
+#define PIN_ZMIN_PULLUP_ENABLED
+
+// TWI
+#define PIN_SDA         IOPORT_CREATE_PIN(PORTC, 4)
+#define PIN_SCL         IOPORT_CREATE_PIN(PORTC, 5)
+
+// TC Settings
+#define TC1_DIV         0b00000011  // 1/64 CPU tick (4 us tick)
+#define TC1_TICK_US     4.0
 
 #endif // CONF_BOARD_H
diff --git a/main.c b/main.c
index ba88187..b8c114c 100644
--- a/main.c
+++ b/main.c
@@ -7,21 +7,24 @@
 
 #include "asf.h"
 #include <stdio.h>
-//#include <avr/stdint.h>
 #include <avr/io.h>
+#include <avr/interrupt.h>
 
 //Internal global variables
+bool current_dir = 1;
+uint16_t step_counter = 0;
 
 //Internal function declarations
+void single_step(void);
+void multi_step(bool dir, uint16_t steps, uint16_t steps_per_s)
 
-void single_step(bool dir);
-
-void single_step(bool dir){
+void single_step(void){
     static bool last_dir = 1;
     
-    if (last_dir != dir) {
-        ioport_set_pin_level(PIN_DIR, dir);
-        last_dir = dir;
+    if (last_dir != current_dir) {
+        ioport_set_pin_level(PIN_DIR, current_dir);
+        delay_us(10);
+        last_dir = current_dir;
     }
     
     ioport_set_pin_level(PIN_STEP, 1);
@@ -32,28 +35,43 @@ void single_step(bool dir){
     return;
 }
 
+void multi_step(bool dir, uint16_t steps, uint16_t us_per_step){
+    current_dir = dir;
+    step_counter = 0;
+    
+    TCCR1A = 0b00000000; // Disable compare
+    TCCR1C = 0b00000000; // Disable force output compare
+    
+    OCR1A = ceil(us_per_step/TC1_TICK_US);
+    TCCR1B |= (1 << WGM12); // CTC mode
+    
+    TIMSK1 |= (1 << OCIE1A); // Enable interrupt
+    TCNT1 = 0;
+    TCCR1B |= TC1_DIV; // Start Timer
+    
+    while (step_counter < steps); // wait until all steps done
+    
+    // stop timer
+    
+    TIMSK1 &= ~(1 << OCIEA1);
+    TCCR1B &= ~(0b00000111);
+}
+
 int main(void){
 	
 	board_init();
-
-	cpu_irq_enable();
-	sysclk_init(); //Disables ALL peripheral clocks D:
 	ioport_init();
+    cpu_irq_enable(); // enable interrupts
     
 	delay_ms(500);
-    bool dir = 1;
 	
-	program_loop:
-    
-        for (uint16_t i = 0; i < 100; i++) {
-            single_step(1);
-            delay_ms(5);
-        }
-    
-        for (uint16_t i = 0; i < 100; i++) {
-            single_step(0);
-            delay_ms(5);
-        }
-    
-	goto program_loop;
+    while (1) {
+        multi_step(1, 40, 2000);
+        multi_step(0, 40, 2000);
+    }
+}
+
+ISR(TIMER1_COMPA_vect){
+    single_step();
+    step_counter++;
 }
\ No newline at end of file
-- 
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