点个灯是为了上手,了解一些最基础的东西,比如程序框架,外设的一般操作方式。
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Alios即然是一个OS,程序框架必然和裸机操作不同,先看个简单的hello-world,代码如下$ c* U+ j' p7 S8 r% a0 B! }% r
- #include <aos/aos.h>$ _% c( U {" v" \
M: r; D& A Q1 [: |4 b- static void app_delayed_action(void *arg)) {) C% K& k+ d9 }6 F
- {
Y/ H+ W2 g1 ?' E3 i - LOG("helloworld %s:%d %s\r\n", __func__, __LINE__, aos_task_name());! k; k! {+ {1 e5 n' h
- aos_post_delayed_action(5000, app_delayed_action, NULL);
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# n4 d: U: Q7 @- int application_start(int argc, char *argv[])
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- LOG("application started.");
) h# O x! J" i$ a' V7 d7 H - aos_post_delayed_action(1000, app_delayed_action, NULL);4 p7 W3 E6 z7 r$ Y0 p5 H
- aos_loop_run();
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- return 0;( k& F1 Y' J$ S, Z. V7 o
- }
复制代码 头文件aos.h是alios动力的源头,先不管有多复杂,照抄就是了。
6 k) |' S: i; g& c% k5 iapplication_start是程序的入口点,硬件上电初始化后,要跳到这里来执行。
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, O; @2 T) I7 e# z R4 ]* ^aos_post_delayed_action(1000, app_delayed_action, NULL)的作用是延迟执行指定的代码,在1秒钟后执行app_delayed_action函数,这个用法有点和Android中的Handler.postDelay方法类似。
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然后在app_delay_action函数中,反复延迟调用自身,从而达到反复执行的目的。( c# n! x2 q0 F: R4 ~
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在入口函数中的aos_loop_run则是进入事件循环,该干啥就干啥。
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点灯用到GPIO,alios要忽略硬件之间的差异,必然得提供一份统一的API及差异化的硬件配置,统一的API提供了GPIO的初始化、读写操作,而差异化的硬件配置则针对特定的硬件平台。
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) n' S) E, `4 O+ Q: t& \这个差异化的配置文件位于board目录下,针对Alios Things Development Kit来说,该文件为/ p D* \1 ~( C C% A
- AliOS-Things\board\developerkit\hal\hal_gpio_stm32_l4.h
复制代码 中,部分代码摘录如下
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9 y3 S5 _' j: Y! Z- #include "stm32l4xx_hal.h"4 v6 U6 {! I# g ^8 u
- #include <string.h>
) E* u: Z. ~8 j - #include <stdlib.h>
$ I- U4 f9 s2 M& a" r, a - #include <stdio.h>' v7 X$ f: U- Z( S4 V% i0 k
- #include <stdbool.h> W1 U. v6 H) M" W
- #include "aos/kernel.h"
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- #define PINS_IN_GROUP 16
3 L/ K$ Q; ^# T6 f- I0 J S& U$ M - #define GROUP_GPIOA 03 P! O! j5 D, N7 S0 H& \* ?
- #define GROUP_GPIOB 1
; n6 Z3 n8 Z) t+ }% |# `8 J4 @ - #define GROUP_GPIOC 2
6 P8 N& Y: d; s! d A- s8 g - #define GROUP_GPIOD 3
O4 Q7 J6 j# s4 U: Y* X: N - #define GROUP_GPIOE 4
" Y% |0 k. v) }/ O/ w( g( m - #define GROUP_GPIOF 5
9 j$ K4 K5 g1 S" Y+ r( F - #define GROUP_GPIOG 60 ^, U# d& x, Y8 A& M
- #define GROUP_GPIOH 7
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- #define HAL_GPIO_0 ((uint8_t)0) /* represent GPIOA pin 0 */9 h7 `' n- i; C9 P" ?9 o
- #define HAL_GPIO_1 ((uint8_t)1) /* represent GPIOA pin 1 */
% v7 v/ X) [# c - #define HAL_GPIO_2 ((uint8_t)2) /* represent GPIOA pin 2 */
8 \: P7 @3 p$ D& f% R - #define HAL_GPIO_3 ((uint8_t)3) /* represent GPIOA pin 3 */
# B" S1 i9 P9 K - #define HAL_GPIO_4 ((uint8_t)4) /* represent GPIOA pin 4 */
. e/ n4 H: s8 P9 r5 a3 ^9 X - #define HAL_GPIO_5 ((uint8_t)5) /* represent GPIOA pin 5 */
1 q5 T4 [$ J$ D5 \ - #define HAL_GPIO_6 ((uint8_t)6) /* represent GPIOA pin 6 */+ l6 }9 a2 ^& A
- #define HAL_GPIO_7 ((uint8_t)7) /* represent GPIOA pin 7 */5 s5 G% i5 |9 v8 a1 [
- #define HAL_GPIO_8 ((uint8_t)8) /* represent GPIOA pin 8 */) b2 G6 A" U4 ?
- #define HAL_GPIO_9 ((uint8_t)9) /* represent GPIOA pin 9 */2 o4 @ N1 ]6 ] f
- #define HAL_GPIO_10 ((uint8_t)10) /* represent GPIOA pin 10 */
6 e. e9 _. |( {( k& z: z - #define HAL_GPIO_11 ((uint8_t)11) /* represent GPIOA pin 11 */1 `) m1 a3 h; Y0 O
- #define HAL_GPIO_12 ((uint8_t)12) /* represent GPIOA pin 12 */- Z$ R! \! w! R5 \9 N; j
- #define HAL_GPIO_13 ((uint8_t)13) /* represent GPIOA pin 13 */& G9 ~; N9 R: r/ B4 r
- #define HAL_GPIO_14 ((uint8_t)14) /* represent GPIOA pin 14 */
% T% [" C) ]! q+ G2 j - #define HAL_GPIO_15 ((uint8_t)15) /* represent GPIOA pin 15 */
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0 y; @- L& H! a8 X2 N& k8 h - #define HAL_GPIO_16 ((uint8_t)16) /* represent GPIOB pin 0 */ f0 v, v1 B. `. x+ z
- #define HAL_GPIO_17 ((uint8_t)17) /* represent GPIOB pin 1 */! m) I% h* U, t9 C/ y
- #define HAL_GPIO_18 ((uint8_t)18) /* represent GPIOB pin 2 */1 x. e5 i. |* F7 `7 Z& ~; T5 k
- #define HAL_GPIO_19 ((uint8_t)19) /* represent GPIOB pin 3 */
* `2 D7 s# P$ m2 N. l - #define HAL_GPIO_20 ((uint8_t)20) /* represent GPIOB pin 4 */
9 ~, t3 i6 R; C - #define HAL_GPIO_21 ((uint8_t)21) /* represent GPIOB pin 5 */" _( y2 H: `2 P% [
- #define HAL_GPIO_22 ((uint8_t)22) /* represent GPIOB pin 6 */; K8 H1 e; O) p( V# L0 s3 Q C
- #define HAL_GPIO_23 ((uint8_t)23) /* represent GPIOB pin 7 */
7 J N8 Y" U+ s/ n) ]8 v3 v - #define HAL_GPIO_24 ((uint8_t)24) /* represent GPIOB pin 8 */$ ]! @. E, A4 P/ K p( B, e
- #define HAL_GPIO_25 ((uint8_t)25) /* represent GPIOB pin 9 */
复制代码 这个倒是非常清楚,不过在官方的文档里却没有提到,需要用户自己去找,找了很久才找到!+ W( l# {1 l. K, `' K( U! X
$ q3 |: l+ s( ^GPIO通用的API列表如下6 ^4 w J7 u1 b' }, k" C
- 1 hal_gpio_init% p; Z3 z2 @0 O M
- 2 hal_gpio_output_high/ J! |8 ^( M7 H% t
- 3 hal_gpio_output_low/ j3 K8 Q; j) b4 E4 d0 [
- 4 hal_gpio_output_toggle; f4 b' s! |3 }# T8 F6 h
- 5 hal_gpio_input_get
0 u' t5 Y/ i+ J9 w3 g! u6 A; }, M4 A - 6 hal_gpio_enable_irq
) _/ o6 z( l/ G* G) x- ` - 7 hal_gpio_disable_irq
2 s; W2 ^2 P% a$ @% x3 | - 8 hal_gpio_clear_irq3 L( K3 N5 L5 P' q9 A+ Y
- 9 hal_gpio_finalize
复制代码 有了这些基础,接下来就可以点灯了。
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开发板上提供了LED1, LED2,LED3,对应的硬件连接如图
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对应前面的GPIO映射得知在ALIOS中其编号为22,接下来修改代码如下
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- #include <aos/aos.h>
) ~; T0 w" h4 \1 `; b# H4 {6 R - #include <hal/soc/soc.h>
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- #define LED1 22
! F+ u. i8 m( R9 ], v - gpio_dev_t led;- a. h6 t e, k3 x8 x f
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- static void app_delayed_action(void *arg)
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- //LOG("helloworld %s:%d %s\r\n", __func__, __LINE__, aos_task_name());
- B( \/ c, D2 O0 Z0 k$ V2 V - hal_gpio_output_toggle(&led);
1 h% ?+ t1 ]- |& M1 c& f' \1 T( ~/ f - aos_post_delayed_action(500, app_delayed_action, NULL);
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- int application_start(int argc, char *argv[])
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- LOG("application started.");
, L! F. q6 U0 h% [* N( J - /* gpio port config */
) O" S* U' m2 O" K" Y* i) i - led.port = LED1;; H$ l' T* C: V
- /* set as output mode */
; B) B. I4 _: k - led.config = OUTPUT_PUSH_PULL;9 u7 |1 Z; x! {* W
- /* configure GPIO with the given settings */& f+ z q4 T p. f' Y1 {$ y
- hal_gpio_init(&led);5 [( [7 q+ U q5 b5 ~. s: e; N
/ v2 Q% m9 @& Z- aos_post_delayed_action(1000, app_delayed_action, NULL);
2 o- q* m" ~ S3 k4 Z2 l2 X - aos_loop_run();
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! a$ H% P& j5 N' s/ j. ~% d' `- return 0;% B0 O3 [( v. S! h1 m. ?
- }
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复制代码
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非常简单的代码,然后编译,上传到开发板,LED1开始闪烁。
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关于开发环境,使用的是VSCode,使用之前记得先安装相关的组件,如下
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然后就可以在VSCode里打开Github上拉下来的代码文件夹,开始体验。* _0 D2 y: P) X7 u0 P
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