added basic stepper support

git-svn-id: https://svn.spreadspace.org/avr/trunk@119 aa12f405-d877-488e-9caf-2d797e2a1cc7

1 files changed, 85 insertions, 0 deletions

diff --git a/usb-i2c-sl018/stepper.c b/usb-i2c-sl018/stepper.c
new file mode 100644
index 0000000..868fff0
--- /dev/null
+++ b/usb-i2c-sl018/stepper.c
@@ -0,0 +1,85 @@
+/*
+ *  spreadspace avr utils
+ *
+ *
+ *  Copyright (C) 2013 Christian Pointner <equinox@spreadspace.org>
+ *                     Othmar Gsenger <otti@wirdorange.org>
+ *
+ *  This file is part of spreadspace avr utils.
+ *
+ *  spreadspace avr utils is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  any later version.
+ *
+ *  spreadspace avr utils is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with spreadspace avr utils. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <avr/sfr_defs.h>
+#include <avr/interrupt.h>
+
+#include "stepper.h"
+
+uint8_t step_table [] = 
+{
+  10, // 1010
+  8,  // 1000
+  9,  // 1001
+  1,  // 0001
+  5,  // 0101
+  4,  // 0100
+  6,  // 0110
+  2,  // 0010
+};
+
+#define STEPPER_PORT PORTF
+#define STEPPER_DDR DDRF
+#define STEPPER_FIRST_BIT 4
+#define STEPPER_ENABLE_BIT 1
+#define LENGTH_STEP_TABLE (sizeof(step_table)/sizeof(uint8_t))
+#define STEPPER_OUTPUT_BITMASK (~(0xF << STEPPER_FIRST_BIT ))
+
+volatile uint16_t step_cnt = 0;
+static uint16_t step_cnt_max = LENGTH_STEP_TABLE*20;
+stepper_direction_t step_direction = dir_open;
+
+void handle_step(void)
+{
+  if(step_cnt < step_cnt_max)
+  {
+    step_cnt++;
+    uint8_t stepper_output=step_table[step_cnt % LENGTH_STEP_TABLE];
+    stepper_output<<=STEPPER_FIRST_BIT;
+    STEPPER_PORT = (STEPPER_PORT & STEPPER_OUTPUT_BITMASK ) | stepper_output;
+  } else {
+    stop_stepper();
+  }
+}
+
+void init_stepper(void)
+{
+  STEPPER_PORT &= ~(0xF << STEPPER_FIRST_BIT | 1<<STEPPER_ENABLE_BIT);
+  STEPPER_DDR |= (0xF << STEPPER_FIRST_BIT) | (1<<STEPPER_ENABLE_BIT);
+}
+
+void start_stepper(stepper_direction_t direction)
+{
+  step_cnt = 0;
+  step_direction = direction;
+  STEPPER_PORT |= 1<<STEPPER_ENABLE_BIT;
+  //start timer here
+}
+
+void stop_stepper(void)
+{
+  // stop timer here
+  STEPPER_PORT &= ~(0xF << STEPPER_FIRST_BIT | 1<<STEPPER_ENABLE_BIT);
+}
+
+