本篇讲解使用ADC进行采样，并使用API将采样值转为电压。
电路原理图
通过hi-12f_v1.1.2-规格书-20211202.pdf 找到IO9对应的ADC通道
GPIO API
| API名称 | 说明 |
| hi_u32 hi_gpio_init(hi_void); | GPIO模块初始化 |
| hi_u32 hi_gpio_set_dir(hi_gpio_idx id, hi_gpio_dir dir); | 设置GPIO引脚方向，id参数用于指定引脚，dir参数用于指定输入或输出 |
| hi_u32 hi_io_set_func(hi_io_name id, hi_u8 val); | 配置某个IO的复用功能 |
| hi_u32 hi_adc_read(hi_adc_channel_index channel, hi_u16 *data, hi_adc_equ_model_sel equ_model, hi_adc_cur_bais cur_bais, hi_u16 delay_cnt); | 从一个ADC通道读一个数据 |
| hi_float hi_adc_convert_to_voltage(hi_u16 data); | 将ADC读取到的码字转换为电压 |
修改D:\DevEcoProjects\test\src\vendor\rtplay\rt_hi3861\demo\BUILD.gn文件
# Copyright (c) 2023 Beijing HuaQing YuanJian Education Technology Co., Ltd
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License. import("//build/lite/config/component/lite_component.gni")lite_component("demo") {features = [#"base_00_helloworld:base_helloworld_example",#"base_01_led:base_led_example",#"base_02_loopkey:base_loopkey_example",#"base_03_irqkey:base_irqkey_example","base_04_adc:base_adc_example",]
}创建D:\DevEcoProjects\test\src\vendor\rtplay\rt_hi3861\demo\base_04_adc文件夹
文件夹中创建D:\DevEcoProjects\test\src\vendor\rtplay\rt_hi3861\demo\base_04_adc\base_adc_example.c文件D:\DevEcoProjects\test\src\vendor\rtplay\rt_hi3861\demo\base_04_adc\BUILD.gn文件
# Copyright (c) 2023 Beijing HuaQing YuanJian Education Technology Co., Ltd
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License. static_library("base_adc_example") {sources = ["base_adc_example.c",]include_dirs = ["//utils/native/lite/include","//kernel/liteos_m/kal/cmsis","//base/iot_hardware/peripheral/interfaces/kits","//vendor/hqyj/fs_hi3861/common/bsp/include"]
}/** Copyright (C) 2023 HiHope Open Source Organization .* Licensed under the Apache License, Version 2.0 (the "License");* you may not use this file except in compliance with the License.* You may obtain a copy of the License at** http://www.apache.org/licenses/LICENSE-2.0** Unless required by applicable law or agreed to in writing, software* distributed under the License is distributed on an "AS IS" BASIS,* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.* See the License for the specific language governing permissions and* limitations under the License.*/#include <stdio.h>
#include <unistd.h>#include "cmsis_os2.h"
#include "hi_adc.h"
#include "hi_errno.h"
#include "hi_gpio.h"
#include "hi_io.h"
#include "ohos_init.h"#define STACK_SIZE (1024)
#define DELAY_US (1000 * 1000) // 延时时间1sstatic void AdcGpioTask(void)
{hi_u16 value; // 存储ADC值while (true) {if (hi_adc_read(HI_ADC_CHANNEL_4, &value, HI_ADC_EQU_MODEL_4, HI_ADC_CUR_BAIS_DEFAULT, 0) != HI_ERR_SUCCESS) {printf("ADC read error!\n");} else {hi_float fv = hi_adc_convert_to_voltage(value);printf("ADC_VALUE = %u %fV\n", (unsigned int)value, fv);}usleep(DELAY_US); // 延时1s}
}static void AdcGpioEntry(void)
{printf("ADC Test!\n");osThreadAttr_t attr;hi_gpio_init(); // GPIO初始化hi_io_set_func(HI_GPIO_IDX_9, HI_IO_FUNC_GPIO_9_GPIO); // 设置GPIO9为GPIO模式hi_gpio_set_dir(HI_GPIO_IDX_9, HI_GPIO_DIR_IN); // 设置GPIO9为输入模式attr.name = "AdcGpioTask";attr.attr_bits = 0U;attr.cb_mem = NULL;attr.cb_size = 0U;attr.stack_mem = NULL;attr.stack_size = STACK_SIZE;attr.priority = osPriorityNormal;if (osThreadNew(AdcGpioTask, NULL, &attr) == NULL) {printf("[ADCExample] Falied to create AdcGpioTask!\n");}
}
SYS_RUN(AdcGpioEntry);目录结构
│ config.json
│
├─common
│ └─bsp
│ ├─include
│ └─src
├─demo
│ │ BUILD.gn
│ │
│ ├─base_00_helloworld
│ │ base_helloworld_example.c
│ │ BUILD.gn
│ │
│ ├─base_01_led
│ │ base_led_example.c
│ │ BUILD.gn
│ │
│ ├─base_02_loopkey
│ │ base_loopkey_example.c
│ │ BUILD.gn
│ │
│ ├─base_03_irqkey
│ │ base_irqkey_example.c
│ │ BUILD.gn
│ │
│ └─base_04_adc
│ base_adc_example.c
│ BUILD.gn
│
└─doc│ HarmonyOS开发板实验指导书 v2.1.pdf│ 华清远见 FS_Hi3861开发指导.md│ 华清远见 FS_Hi3861新手入门手册.md│├─board│ FS-Hi3861-V4.2.pdf│ FS-Hi3861QDB-V3.2.pdf│ hi-12f_kit_v1.1.0规格书-20211025.pdf│ hi-12f_v1.1.2-规格书-20211202.pdf│ nodemcu-hi-07s_12f-kit_v1.1-20210913.pdf│ RTplay2.01_2024-06-14.pdf│└─figures使用build，编译成功后，使用upload进行烧录。
运行效果如下，用螺丝刀旋转滑动变阻器会使采样值变化。
