STM32模拟I2C获取AP3216C光学接近传感器数据
AP3216C是一款三合一的光学传感器。这块传感器集成了光强传感器（ALS: AmbientLight Sensor），接近传感器（PS: Proximity Sensor），还有一个红外LED（Infrared LED）。
这款光学传感器可以单独进行环境光的检测，单独进行红外环境光的检测，以及通过自带LED的发光进行接近距离的检测。也支持进行交替检测。在具体的应用模式上有连续性检测模式和单次检测模式。由于有比较好的性价比，可以用在灰度检测，循迹等场景，多颗配合还可以实现手势检测。
AP3216C传感器的体积较小，做成模块体积也不大，能够应用在空间小的环境实现光学强度检测，且具有对弱反光环境的检测能力，具有日常交流噪声的抑制能力，具有温度补偿能力及LED发光强度4级可调。
这里以STM32F401CCU6为例, 采用STM32CUBEIDE开发环境，实现AP3216C的控制和数据获取。
STM32工程配置
首先建立工程并配置时钟：
配置两个GPIO用于模拟I2C, 采用Open Drain配置方式：
这里采用USB串口的方式输出数据，所以例化USB端口为Virtual Port，采用默认参数即可：
保存并生成初始工程代码：
STM32模拟I2C代码
实现模拟I2C协议需要用到微秒级延时函数，采用 STM32 HAL us delay（微秒延时）的指令延时实现方式及优化 里的函数实现。
#define us_num 10
#define SCL_OUT_H HAL_GPIO_WritePin(GPIOB, GPIO_PIN_6, GPIO_PIN_SET)
#define SCL_OUT_L HAL_GPIO_WritePin(GPIOB, GPIO_PIN_6, GPIO_PIN_RESET)
#define SDA_OUT_H HAL_GPIO_WritePin(GPIOB, GPIO_PIN_7, GPIO_PIN_SET)
#define SDA_OUT_L HAL_GPIO_WritePin(GPIOB, GPIO_PIN_7, GPIO_PIN_RESET)
#define SDA_IN HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_7)
void I2C_Init(void)
{
SDA_OUT_H;
SCL_OUT_H;
PY_Delay_us_t(1000000) ;
}
void I2C_Start(void)
{
PY_Delay_us_t(us_num) ;
SDA_OUT_H;
SCL_OUT_H;
PY_Delay_us_t(us_num/2) ;
SDA_OUT_L;
PY_Delay_us_t(us_num/2) ;
SCL_OUT_L;
}
void I2C_Stop(void)
{
SCL_OUT_L;
PY_Delay_us_t(us_num) ;
SDA_OUT_L;
PY_Delay_us_t(us_num) ;
SCL_OUT_H;
PY_Delay_us_t(us_num) ;
SDA_OUT_H;
PY_Delay_us_t(us_num) ;
}
void I2C_Write_Ack(void)
{
PY_Delay_us_t(us_num/2) ;
SDA_OUT_L;
PY_Delay_us_t(us_num/2) ;
SCL_OUT_H;
PY_Delay_us_t(us_num) ;
SCL_OUT_L;
SDA_OUT_H;
}
uint8_t I2C_Read_Ack(void)
{
uint8_t status=0;
SCL_OUT_L;
PY_Delay_us_t(us_num/2) ;
SDA_OUT_H;
PY_Delay_us_t(us_num/2) ;
status = SDA_IN;
SCL_OUT_H;
PY_Delay_us_t(us_num) ;
SCL_OUT_L;
SDA_OUT_L;
return status;
}
void I2C_Send_Byte(uint8_t txd)
{
for(uint8_t i=0;i<8;i++)
{
PY_Delay_us_t(us_num/2) ;
if((txd&0x80)>>7) SDA_OUT_H;
else SDA_OUT_L;
txd<<=1;
PY_Delay_us_t(us_num/2) ;
SCL_OUT_H;
PY_Delay_us_t(us_num) ;
SCL_OUT_L;
}
SDA_OUT_L;
}
uint8_t I2C_Read_Byte(unsigned char rdack)
{
uint8_t rxd=0;
for(uint8_t i=0;i<8;i++ )
{
SCL_OUT_L;
PY_Delay_us_t(us_num/2) ;
SDA_OUT_H;
PY_Delay_us_t(us_num/2) ;
SCL_OUT_H;
rxd<<=1;
if(SDA_IN) rxd++;
PY_Delay_us_t(us_num) ;
}
SCL_OUT_L;
SDA_OUT_H;
if (rdack) I2C_Write_Ack();
return rxd;
}
void AP3216_WRITE( uint8_t WrAddr, uint8_t data)
{
uint8_t daddr = 0x3c; //AP3216 device address (0x1e<<1)
I2C_Start();
I2C_Send_Byte(daddr);
I2C_Read_Ack();
I2C_Send_Byte(WrAddr);
I2C_Read_Ack();
I2C_Send_Byte(data);
I2C_Read_Ack();
I2C_Stop();
}
uint8_t AP3216_READ( uint8_t RdAddr)
{
uint8_t RegValue = 0;
uint8_t daddr = 0x3c; //AP3216 device address (0x1e<<1)
I2C_Start();
I2C_Send_Byte(daddr);
I2C_Read_Ack();
I2C_Send_Byte(RdAddr);
I2C_Read_Ack();
I2C_Start();
I2C_Send_Byte(daddr+1);
I2C_Read_Ack();
RegValue=I2C_Read_Byte(0);
I2C_Stop();
return RegValue;
}
STM32完整工程代码
这里实现的完整工程代码，通过预定义参数控制实现环境白光(ALS)，环境红外光(IR)，接近反光(PS)的其中一种检测，而其它的各种方式以及中断实现方式，都可以在此协议访问基础上进行扩展实现。
#define DMODE 0 //Detecting mode for AP3216. 0: ALS read only; 1: IR read only; 2: PS read only; ......
需要注意的是，环境红外光和接近反光（PS+IR）是集成在一个检测部分，因此是同时使能，在做环境红外光检测时，配置接近反光的LED为关闭状态。另外，在做接近反光检测时，环境红外光检测也是在工作，此时实际上一个检测周期是如下的概念：
在PS检测前进行IR检测的目的是对环境红外噪光强度进行识别，以利于判断后面PS检测的有效性。
完整的工程实现代码如下：
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* Copyright (c) 2022 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "usb_device.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#define DMODE 0 //Detecting mode for AP3216. 0: ALS read only; 1: IR read only; 2: PS read only; ......
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
__IO float usDelayBase;
void PY_usDelayTest(void)
{
__IO uint32_t firstms, secondms;
__IO uint32_t counter = 0;
firstms = HAL_GetTick()+1;
secondms = firstms+1;
while(uwTick!=firstms) ;
while(uwTick!=secondms) counter++;
usDelayBase = ((float)counter)/1000;
}
void PY_Delay_us_t(uint32_t Delay)
{
__IO uint32_t delayReg;
__IO uint32_t usNum = (uint32_t)(Delay*usDelayBase);
delayReg = 0;
while(delayReg!=usNum) delayReg++;
}
void PY_usDelayOptimize(void)
{
__IO uint32_t firstms, secondms;
__IO float coe = 1.0;
firstms = HAL_GetTick();
PY_Delay_us_t(1000000) ;
secondms = HAL_GetTick();
coe = ((float)1000)/(secondms-firstms);
usDelayBase = coe*usDelayBase;
}
void PY_Delay_us(uint32_t Delay)
{
__IO uint32_t delayReg;
__IO uint32_t msNum = Delay/1000;
__IO uint32_t usNum = (uint32_t)((Delay%1000)*usDelayBase);
if(msNum>0) HAL_Delay(msNum);
delayReg = 0;
while(delayReg!=usNum) delayReg++;
}
#define us_num 10
#define SCL_OUT_H HAL_GPIO_WritePin(GPIOB, GPIO_PIN_6, GPIO_PIN_SET)
#define SCL_OUT_L HAL_GPIO_WritePin(GPIOB, GPIO_PIN_6, GPIO_PIN_RESET)
#define SDA_OUT_H HAL_GPIO_WritePin(GPIOB, GPIO_PIN_7, GPIO_PIN_SET)
#define SDA_OUT_L HAL_GPIO_WritePin(GPIOB, GPIO_PIN_7, GPIO_PIN_RESET)
#define SDA_IN HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_7)
void I2C_Init(void)
{
SDA_OUT_H;
SCL_OUT_H;
PY_Delay_us_t(1000000) ;
}
void I2C_Start(void)
{
PY_Delay_us_t(us_num) ;
SDA_OUT_H;
SCL_OUT_H;
PY_Delay_us_t(us_num/2) ;
SDA_OUT_L;
PY_Delay_us_t(us_num/2) ;
SCL_OUT_L;
}
void I2C_Stop(void)
{
SCL_OUT_L;
PY_Delay_us_t(us_num) ;
SDA_OUT_L;
PY_Delay_us_t(us_num) ;
SCL_OUT_H;
PY_Delay_us_t(us_num) ;
SDA_OUT_H;
PY_Delay_us_t(us_num) ;
}
void I2C_Write_Ack(void)
{
PY_Delay_us_t(us_num/2) ;
SDA_OUT_L;
PY_Delay_us_t(us_num/2) ;
SCL_OUT_H;
PY_Delay_us_t(us_num) ;
SCL_OUT_L;
SDA_OUT_H;
}
uint8_t I2C_Read_Ack(void)
{
uint8_t status=0;
SCL_OUT_L;
PY_Delay_us_t(us_num/2) ;
SDA_OUT_H;
PY_Delay_us_t(us_num/2) ;
status = SDA_IN;
SCL_OUT_H;
PY_Delay_us_t(us_num) ;
SCL_OUT_L;
SDA_OUT_L;
return status;
}
void I2C_Send_Byte(uint8_t txd)
{
for(uint8_t i=0;i<8;i++)
{
PY_Delay_us_t(us_num/2) ;
if((txd&0x80)>>7) SDA_OUT_H;
else SDA_OUT_L;
txd<<=1;
PY_Delay_us_t(us_num/2) ;
SCL_OUT_H;
PY_Delay_us_t(us_num) ;
SCL_OUT_L;
}
SDA_OUT_L;
}
uint8_t I2C_Read_Byte(unsigned char rdack)
{
uint8_t rxd=0;
for(uint8_t i=0;i<8;i++ )
{
SCL_OUT_L;
PY_Delay_us_t(us_num/2) ;
SDA_OUT_H;
PY_Delay_us_t(us_num/2) ;
SCL_OUT_H;
rxd<<=1;
if(SDA_IN) rxd++;
PY_Delay_us_t(us_num) ;
}
SCL_OUT_L;
SDA_OUT_H;
if (rdack) I2C_Write_Ack();
return rxd;
}
void AP3216_WRITE( uint8_t WrAddr, uint8_t data)
{
uint8_t daddr = 0x3c; //AP3216 device address (0x1e<<1)
I2C_Start();
I2C_Send_Byte(daddr);
I2C_Read_Ack();
I2C_Send_Byte(WrAddr);
I2C_Read_Ack();
I2C_Send_Byte(data);
I2C_Read_Ack();
I2C_Stop();
}
uint8_t AP3216_READ( uint8_t RdAddr)
{
uint8_t RegValue = 0;
uint8_t daddr = 0x3c; //AP3216 device address (0x1e<<1)
I2C_Start();
I2C_Send_Byte(daddr);
I2C_Read_Ack();
I2C_Send_Byte(RdAddr);
I2C_Read_Ack();
I2C_Start();
I2C_Send_Byte(daddr+1);
I2C_Read_Ack();
RegValue=I2C_Read_Byte(0);
I2C_Stop();
return RegValue;
}
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
uint8_t rdata[3];
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN PV */
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
/* USER CODE BEGIN PFP */
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_USB_DEVICE_Init();
/* USER CODE BEGIN 2 */
PY_usDelayTest();
PY_usDelayOptimize();
I2C_Init();
/*
* 000: Power down (Default)
* 001: ALS function active
* 010: PS+IR function active. The IR DATA can show the intensity of environment IR.
* 011: ALS and PS+IR functions active. The device will operate the ALS and PS+IR function alternately.
* 100: SW reset
* 101: ALS function once
* 110: PS+IR function once
* 111: ALS and PS+IR functions once
*/
AP3216_WRITE(0x00, 0x00);
PY_Delay_us_t(100000);
if(DMODE==0)
{
//ALS Read Only
AP3216_WRITE(0x00, 0x01); //ALS mode
PY_Delay_us_t(100000);
AP3216_WRITE(0x10, 0x10); //Resolution
PY_Delay_us_t(100000);
AP3216_WRITE(0x19, 0x40); //Loss calibration
PY_Delay_us_t(100000);
rdata[2]=0xff;
while(1)
{
__disable_irq();
rdata[0]= AP3216_READ(0x0c);
rdata[1] = AP3216_READ(0x0d);
__enable_irq();
CDC_Transmit_FS(rdata, 3);
PY_Delay_us_t(1000000);
}
}
if(DMODE==1)
{
//IR Read Only
AP3216_WRITE(0x00, 0x02);
PY_Delay_us_t(100000);
AP3216_WRITE(0x20, 0x05); //PS config: default
PY_Delay_us_t(100000);
AP3216_WRITE(0x21, 0x03); //Close LED pulse
PY_Delay_us_t(100000);
AP3216_WRITE(0x23, 0x00); //T(PS mean time) config: default
PY_Delay_us_t(100000);
AP3216_WRITE(0x24, 0x00); //PS LED waiting time: default
PY_Delay_us_t(100000);
rdata[2]=0xff;
while(1)
{
__disable_irq();
rdata[0]= AP3216_READ(0x0A);
if((rdata[0]>>7)>0)
{
rdata[0]=0xff;
rdata[1]=0xff;
}
else
{
rdata[1] = AP3216_READ(0x0B);
rdata[0] = (rdata[0]&0x3)|(rdata[1]<<2);
rdata[1] >>= 6;
}
__enable_irq();
CDC_Transmit_FS(rdata, 3);
PY_Delay_us_t(100000);
}
}
if(DMODE==2)
{
//PS Read Only
AP3216_WRITE(0x00, 0x02);
PY_Delay_us_t(100000);
AP3216_WRITE(0x20, 0x05); //PS config: default
PY_Delay_us_t(100000);
AP3216_WRITE(0x21, 0x13); //LED pulse and driving current strength
PY_Delay_us_t(100000);
AP3216_WRITE(0x23, 0x00); //T(PS mean time) config: default
PY_Delay_us_t(100000);
AP3216_WRITE(0x24, 0x00); //PS LED waiting time: default
PY_Delay_us_t(100000);
AP3216_WRITE(0x28, 0x00); PY_Delay_us_t(100000);AP3216_WRITE(0x29, 0x00);//PS Calibration
PY_Delay_us_t(100000);
rdata[2]=0xff;
while(1)
{
__disable_irq();
rdata[0]= AP3216_READ(0x0E);
if((rdata[0]&0x40)>0)
{
rdata[0]=0xff;
rdata[1]=0xff;
}
else
{
rdata[1] = AP3216_READ(0x0F)&0x3F;
rdata[0] = (rdata[0]&0x0F)|(rdata[1]<<4);
rdata[1] >>= 4;
}
__enable_irq();
CDC_Transmit_FS(rdata, 3);
PY_Delay_us_t(100000);
}
}
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
PY_Delay_us(1000000);
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
}
/* USER CODE END 3 */
}
/**
* @brief System Clock Configuration
* @retval None
*/
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
/** Configure the main internal regulator output voltage
*/
__HAL_RCC_PWR_CLK_ENABLE();
__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE2);
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_ON;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLM = 25;
RCC_OscInitStruct.PLL.PLLN = 336;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4;
RCC_OscInitStruct.PLL.PLLQ = 7;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
/** Initializes the CPU, AHB and APB buses clocks
*/
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
{
Error_Handler();
}
}
/**
* @brief GPIO Initialization Function
* @param None
* @retval None
*/
static void MX_GPIO_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOH_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
__HAL_RCC_GPIOB_CLK_ENABLE();
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(GPIOB, GPIO_PIN_6|GPIO_PIN_7, GPIO_PIN_SET);
/*Configure GPIO pins : PB6 PB7 */
GPIO_InitStruct.Pin = GPIO_PIN_6|GPIO_PIN_7;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_OD;
GPIO_InitStruct.Pull = GPIO_PULLUP;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
}
/* USER CODE BEGIN 4 */
/* USER CODE END 4 */
/**
* @brief This function is executed in case of error occurrence.
* @retval None
*/
void Error_Handler(void)
{
/* USER CODE BEGIN Error_Handler_Debug */
/* User can add his own implementation to report the HAL error return state */
__disable_irq();
while (1)
{
}
/* USER CODE END Error_Handler_Debug */
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t *file, uint32_t line)
{
/* USER CODE BEGIN 6 */
/* User can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
STM32例程下载
采用RT-THREAD NANO操作系统的普通串口输出的例程下载
–End–