Zoul: generic servo driver

2016-08-22 12:36:12 +02:00 · 2016-08-22 12:36:12 +02:00 · 8cc1870663
commit 8cc1870663
parent 6947fc7381
7 changed files with 393 additions and 8 deletions
--- a/platform/zoul/dev/servo.c
+++ b/platform/zoul/dev/servo.c
@ -0,0 +1,132 @@
+/*
+ * Copyright (c) 2016, Zolertia - http://www.zolertia.com
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ */
+/*---------------------------------------------------------------------------*/
+/**
+ * \addtogroup zoul-servo
+ * @{
+ *
+ * \file
+ *  Driver for a generic Servo driver
+ *
+ * \author
+ *         Antonio Lignan <alinan@zolertia.com>
+ */
+/*---------------------------------------------------------------------------*/
+#include "contiki.h"
+#include "dev/pwm.h"
+#include "dev/gpio.h"
+#include "servo.h"
+/*---------------------------------------------------------------------------*/
+#define DEBUG 0
+#if DEBUG
+#define PRINTF(...) printf(__VA_ARGS__)
+#else
+#define PRINTF(...)
+#endif
+/*---------------------------------------------------------------------------*/
+int
+servo_position(uint16_t gptab, uint8_t port, uint8_t pin, uint16_t pos)
+{
+  uint8_t gpt_num;
+  uint8_t gpt_ab;
+  uint32_t count = 0;
+
+  if((gptab < SERVO_CHANNEL_1) && (gptab > SERVO_CHANNEL_7)) {
+    PRINTF("Servo: invalid servo channel\n");
+    return SERVO_ERROR;
+  }
+
+  /* CC2538 has 4 ports (A-D) and up to 8 pins (0-7) */
+  if((port > GPIO_D_NUM) || (pin > 7)) {
+    PRINTF("Servo: Invalid pin/port settings\n");
+    return SERVO_ERROR;
+  }
+
+  if(pos > SERVO_MAX_DEGREES) {
+    PRINTF("Servo: invalid position (max %u)\n", SERVO_MAX_DEGREES);
+    return SERVO_ERROR;
+  }
+
+  count = (SERVO_MAX_VAL - SERVO_MIN_VAL) * pos;
+  count /= SERVO_MAX_DEGREES;
+  count += SERVO_MIN_VAL;
+
+  gpt_num = (uint8_t)(gptab >> 8);
+  gpt_ab =  (uint8_t)(gptab & 0x00FF);
+
+  PRINTF("Servo: F%uHz GPTNUM %u GPTAB %u --> %uº (%lu)\n", SERVO_DEFAULT_FREQ,
+                                                            gpt_num, gpt_ab,
+                                                            pos, count);
+  /* Use count as argument instead of percentage */
+  if(pwm_enable(SERVO_DEFAULT_FREQ, 0, count, gpt_num,gpt_ab) != PWM_SUCCESS) {
+    PRINTF("Servo: failed to configure the pwm channel\n");
+    return SERVO_ERROR;
+  }
+
+  /* Start the PWM as soon as possible, keep the pulses to lock the servo in the
+   * given position
+   */
+  if(pwm_start(gpt_num, gpt_ab, port, pin) != PWM_SUCCESS) {
+    PRINTF("Servo: failed to initialize the pwm channel\n");
+    return SERVO_ERROR;
+  }
+
+  return SERVO_SUCCESS;
+}
+/*---------------------------------------------------------------------------*/
+int
+servo_stop(uint16_t gptab, uint8_t port, uint8_t pin)
+{
+  uint8_t gpt_num;
+  uint8_t gpt_ab;
+
+  if((gptab < SERVO_CHANNEL_1) && (gptab > SERVO_CHANNEL_7)) {
+    PRINTF("Servo: invalid servo channel\n");
+    return SERVO_ERROR;
+  }
+
+  /* CC2538 has 4 ports (A-D) and up to 8 pins (0-7) */
+  if((port > GPIO_D_NUM) || (pin > 7)) {
+    PRINTF("Servo: Invalid pin/port settings\n");
+    return SERVO_ERROR;
+  }
+
+  gpt_num = (uint8_t)((gptab & 0xFF00) >> 8);
+  gpt_ab =  (uint8_t)(gptab & 0x00FF);
+
+  if(pwm_disable(gpt_num, gpt_ab, port, pin) != PWM_SUCCESS) {
+    PRINTF("Servo: unable to disable the pwm channel\n");
+    return SERVO_ERROR;
+  }
+
+  return SERVO_SUCCESS;
+}
+/*---------------------------------------------------------------------------*/
+/** @} */