CMSIS2000  0.0.7
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led.c
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1 /**
2  * Copyright (c) 2012, Roy van Dam <roy@vandam-innovations.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 are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright notice, this
9  * list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright notice,
11  * this list of conditions and the following disclaimer in the documentation
12  * and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
16  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
17  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
18  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
19  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
20  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
21  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
23  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25 
26 #include "led.h"
27 
28 void assert_param(bool value) {
29  if (value == false) {
30  // XXX: Debug on failed assertion.
31  }
32 }
33 
34 volatile unsigned long system_tick_count = 0;
35 
36 void SysTick_Handler(void) {
37  system_tick_count++;
38 }
39 
40 void SysTick_Delay(unsigned long ms) {
41  unsigned long target_tick_count = system_tick_count + ms;
42 
43  // Handle timer overflow
44  if (target_tick_count < system_tick_count)
45  while (system_tick_count > target_tick_count);
46 
47  // Wait for time to pass
48  while (system_tick_count < target_tick_count);
49 }
50 
51 void Led_Init(LedId led) {
52  GPIO_InitTypeDef GPIO_Context;
53 
54  RCC_APB2PeriphClockCmd(led_context[led].clock, ENABLE);
55 
56  GPIO_Context.GPIO_Pin = led_context[led].pin;
57  GPIO_Context.GPIO_Mode = GPIO_Mode_Out_PP;
58  GPIO_Context.GPIO_Speed = GPIO_Speed_50MHz;
59 
60  GPIO_Init(led_context[led].port, &GPIO_Context);
61 }
62 
63 void Led_Enable(LedId led) {
64  led_context[led].port->BSRR = led_context[led].pin;
65 }
66 void Led_Disable(LedId led) {
67  led_context[led].port->BRR = led_context[led].pin;
68 }
69 
70 int main(void) {
71  Led_Init(LED0);
72  Led_Disable(LED0);
73 
74  Led_Init(LED1);
75  Led_Disable(LED1);
76 
77  while(1) {
78  Led_Enable(LED1);
79  SysTick_Delay(500);
80  Led_Disable(LED1);
81  SysTick_Delay(500);
82  }
83 }