Contiki-NG
servo.c
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1 /*
2  * Copyright (c) 2016, Zolertia - http://www.zolertia.com
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  * notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  * notice, this list of conditions and the following disclaimer in the
12  * documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the Institute nor the names of its contributors
14  * may be used to endorse or promote products derived from this software
15  * without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  */
30 /*---------------------------------------------------------------------------*/
31 /**
32  * \addtogroup zoul-servo
33  * @{
34  *
35  * \file
36  * Driver for a generic Servo driver
37  *
38  * \author
39  * Antonio Lignan <alinan@zolertia.com>
40  */
41 /*---------------------------------------------------------------------------*/
42 #include "contiki.h"
43 #include "dev/pwm.h"
44 #include "dev/gpio.h"
45 #include "servo.h"
46 /*---------------------------------------------------------------------------*/
47 #define DEBUG 0
48 #if DEBUG
49 #define PRINTF(...) printf(__VA_ARGS__)
50 #else
51 #define PRINTF(...)
52 #endif
53 /*---------------------------------------------------------------------------*/
54 int
55 servo_position(uint16_t gptab, uint8_t port, uint8_t pin, uint16_t pos)
56 {
57  uint8_t gpt_num;
58  uint8_t gpt_ab;
59  uint32_t count = 0;
60 
61  if((gptab < SERVO_CHANNEL_1) && (gptab > SERVO_CHANNEL_7)) {
62  PRINTF("Servo: invalid servo channel\n");
63  return SERVO_ERROR;
64  }
65 
66  /* CC2538 has 4 ports (A-D) and up to 8 pins (0-7) */
67  if((port > GPIO_D_NUM) || (pin > 7)) {
68  PRINTF("Servo: Invalid pin/port settings\n");
69  return SERVO_ERROR;
70  }
71 
72  if(pos > SERVO_MAX_DEGREES) {
73  PRINTF("Servo: invalid position (max %u)\n", SERVO_MAX_DEGREES);
74  return SERVO_ERROR;
75  }
76 
77  count = (SERVO_MAX_VAL - SERVO_MIN_VAL) * pos;
78  count /= SERVO_MAX_DEGREES;
79  count += SERVO_MIN_VAL;
80 
81  gpt_num = (uint8_t)(gptab >> 8);
82  gpt_ab = (uint8_t)(gptab & 0x00FF);
83 
84  PRINTF("Servo: F%uHz GPTNUM %u GPTAB %u --> %uÂș (%lu)\n", SERVO_DEFAULT_FREQ,
85  gpt_num, gpt_ab,
86  pos, count);
87  /* Use count as argument instead of percentage */
88  if(pwm_enable(SERVO_DEFAULT_FREQ, 0, count, gpt_num,gpt_ab) != PWM_SUCCESS) {
89  PRINTF("Servo: failed to configure the pwm channel\n");
90  return SERVO_ERROR;
91  }
92 
93  /* Start the PWM as soon as possible, keep the pulses to lock the servo in the
94  * given position
95  */
96  if(pwm_start(gpt_num, gpt_ab, port, pin) != PWM_SUCCESS) {
97  PRINTF("Servo: failed to initialize the pwm channel\n");
98  return SERVO_ERROR;
99  }
100 
101  return SERVO_SUCCESS;
102 }
103 /*---------------------------------------------------------------------------*/
104 int
105 servo_stop(uint16_t gptab, uint8_t port, uint8_t pin)
106 {
107  uint8_t gpt_num;
108  uint8_t gpt_ab;
109 
110  if((gptab < SERVO_CHANNEL_1) && (gptab > SERVO_CHANNEL_7)) {
111  PRINTF("Servo: invalid servo channel\n");
112  return SERVO_ERROR;
113  }
114 
115  /* CC2538 has 4 ports (A-D) and up to 8 pins (0-7) */
116  if((port > GPIO_D_NUM) || (pin > 7)) {
117  PRINTF("Servo: Invalid pin/port settings\n");
118  return SERVO_ERROR;
119  }
120 
121  gpt_num = (uint8_t)((gptab & 0xFF00) >> 8);
122  gpt_ab = (uint8_t)(gptab & 0x00FF);
123 
124  if(pwm_disable(gpt_num, gpt_ab, port, pin) != PWM_SUCCESS) {
125  PRINTF("Servo: unable to disable the pwm channel\n");
126  return SERVO_ERROR;
127  }
128 
129  return SERVO_SUCCESS;
130 }
131 /*---------------------------------------------------------------------------*/
132 /** @} */
Header file for the CC2538 PWM driver.
int servo_stop(uint16_t gptab, uint8_t port, uint8_t pin)
Fully stop a servo and reconfigures back the pin/port as GPIO.
Definition: servo.c:105
Header file with register and macro declarations for the cc2538 GPIO module.
int8_t pwm_start(uint8_t timer, uint8_t ab, uint8_t port, uint8_t pin)
Once configured, starts the PWM.
Definition: pwm.c:235
Header file for a Generic Servo driver.
#define SERVO_CHANNEL_7
GPT3-B.
Definition: servo.h:95
#define SERVO_DEFAULT_FREQ
50 Hz
Definition: servo.h:61
#define GPIO_D_NUM
GPIO_D: 3.
Definition: gpio.h:67
#define SERVO_CHANNEL_1
GPT0-B.
Definition: servo.h:89
int servo_position(uint16_t gptab, uint8_t port, uint8_t pin, uint16_t pos)
Configures and positions a servo in a given position (by degrees) The servo will lock its position as...
Definition: servo.c:55
int8_t pwm_enable(uint32_t freq, uint8_t duty, uint32_t count, uint8_t timer, uint8_t ab)
Configures the general purpose timer in PWM mode.
Definition: pwm.c:93
int8_t pwm_disable(uint8_t timer, uint8_t ab, uint8_t port, uint8_t pin)
Disables a previously PWM configured GPTn.
Definition: pwm.c:330