1. Introduction
Official data sheet: https://pan.baidu.com/s/1Y0M4ImNsBvAvECy-yNUvxg Extraction code: itsr
- Ultra low noise, high resolution 0.001°/√Hz
- SPI digital interface
- Superior mechanical damping characteristics
- Operating temperature range: -40~125℃
- Current consumption 1.2mA (power supply: 3.0~3.6V)
- Mature capacitance 3D-MEMS technology
2. Hardware connection
| Function port | Pin |
|---|---|
| MISO | 17 |
| DAWDLE | 18 |
| CLK | 20 |
| CSN | 19 |
Three, add SPI driver
View NRF52832 study notes (5)-SPI interface use
The official document recommends the SPI clock because SCK will affect the noise level of SCL3300. It is recommended that the clock frequency be 2MHz~4MHz for optimal performance.
Modify the SPI frequency to 4MHz,SPI_FREQUENCY_FREQUENCY_M4
Four, transplant files
Link: https://pan.baidu.com/s/1fS7LCpQW36QGIvJBoxP4gQ extraction code: 3opk
adds board_scl3300.c and board_scl3300.h to the Application folder of the project
4.1 board_scl3300.c
/*********************************************************************
* INCLUDES
*/
#include "nrf_delay.h"
#include "board_scl3300.h"
#include "board_spi.h"
static void writeRegister(uint32_t cmd);
static void readRegister(void);
static void delayMs(uint32_t time);
static void delayUs(uint32_t time);
/*********************************************************************
* LOCAL VARIABLES
*/
static uint8_t s_readData[4] = {
0};
/*********************************************************************
* PUBLIC FUNCTIONS
*/
/**
@brief SCL3300的初始化函数
@param 无
@return 无
*/
void SCL3300_Init(void)
{
delayMs(10);
writeRegister(CHANGE_TO_MODE4); // 选择倾角模式
readRegister();
delayMs(5);
writeRegister(READ_STATUS_SUMMARY); // 清除状态
readRegister();
writeRegister(READ_STATUS_SUMMARY);
readRegister();
writeRegister(READ_STATUS_SUMMARY);
readRegister();
writeRegister(ENABLE_ANGLE_OUTPUTS); // 使能角度输出
readRegister();
}
/**
@brief 检查SPI通信，返回值第3字节为0xC1则通信正常
@param 无
@return 无
*/
void SCL3300_Test(void)
{
writeRegister(READ_ID);
readRegister();
// 打印s_readData[2]
}
/**
@brief 读取角度
@param direction -[in] 要读取的方向X，Y，Z轴
@return 角度数
*/
float SCL3300_ReadAngle(uint8_t direction)
{
if(direction == ANG_X)
{
writeRegister(READ_ANG_X);
}
else if(direction == ANG_Y)
{
writeRegister(READ_ANG_Y);
}
else if(direction == ANG_Z)
{
writeRegister(READ_ANG_Z);
}
readRegister();
// SPI返回结构第1字节OP+RS，
uint16_t angle = (s_readData[1] << 8) + s_readData[2]; // 第2和第3字节为Data
// 第4字节为CRC
float fangle = (float)angle / 16384.0 * 90.0; // 如3976/2^14*90=21.84°
return fangle;
}
/*********************************************************************
* LOCAL FUNCTIONS
*/
/**
@brief 写SCL3300寄存器
@param cmd -[in] 写入命令
@return 无
*/
static void writeRegister(uint32_t cmd)
{
uint8_t writeData[4] = {
0};
writeData[0] = (cmd >> 24) & 0xFF;
writeData[1] = (cmd >> 16) & 0xFF;
writeData[2] = (cmd >> 8) & 0xFF;
writeData[3] = (cmd >> 0) & 0xFF;
SPI_CS_LOW;
SPI_ReadWriteData(writeData, NULL, 4);
SPI_CS_HIGH;
delayUs(10);
}
/**
@brief 读SCL3300寄存器
@param 无
@return 无
*/
static void readRegister(void)
{
SPI_CS_LOW;
SPI_ReadWriteData(NULL, s_readData, 4);
SPI_CS_HIGH;
delayUs(10);
}
/**
@brief 毫秒级延时函数
@param time -[in] 延时时间（毫秒）
@return 无
*/
static void delayMs(uint32_t time)
{
nrf_delay_ms(time);
}
/**
@brief 微秒级延时函数
@param time -[in] 延时时间（微秒）
@return 无
*/
static void delayUs(uint32_t time)
{
nrf_delay_us(time);
}
/****************************************************END OF FILE****************************************************/
4.2 board_scl3300.h
#ifndef _BOARD_SCL3300_H_
#define _BOARD_SCL3300_H_
/*********************************************************************
* INCLUDES
*/
/*********************************************************************
* DEFINITIONS
*/
#define ANG_X 0
#define ANG_Y 1
#define ANG_Z 2
//******************************************************************/
// 传感数据 /
//******************************************************************/
#define READ_ACC_X 0x040000F7
#define READ_ACC_Y 0x080000FD
#define READ_ACC_Z 0x0C0000FB
#define READ_TEMPERATURE 0x140000EF
#define READ_ANG_X 0x240000C7
#define READ_ANG_Y 0x280000CD
#define READ_ANG_Z 0x2C0000CB
//******************************************************************/
// 自我检测 /
//******************************************************************/
#define READ_STO 0x100000E9
//******************************************************************/
// 状态 /
//******************************************************************/
#define READ_STATUS_SUMMARY 0x180000E5
//******************************************************************/
// 错误标志 /
//******************************************************************/
#define READ_ERR_FLAG1 0x1C0000E3
#define READ_ERR_FLAG2 0x200000C1
//******************************************************************/
// 命令 /
//******************************************************************/
#define READ_CMD 0x340000DF
#define CHANGE_TO_MODE1 0xB400001F // 默认模式，1.8g full-scale 40 Hz 1st order low pass filter
#define CHANGE_TO_MODE2 0xB4000102 // 23.6g full-scale 70 Hz 1st order low pass filter
#define CHANGE_TO_MODE3 0xB4000225 // Inclination mode 13 Hz 1st order low pass filter
#define CHANGE_TO_MODE4 0xB4000338 // Inclination mode 13 Hz 1st order low pass filter Low noise mode
#define SET_POWER_DOWN_MODE 0xB400046B
#define WAKE_UP 0xB400001F
#define SW_RESET 0xB4002098
//******************************************************************/
// 角度控制 /
//******************************************************************/
#define ENABLE_ANGLE_OUTPUTS 0xB0001F6F
//******************************************************************/
// 芯片ID /
//******************************************************************/
#define READ_ID 0x40000091
//******************************************************************/
// 串行块 /
//******************************************************************/
#define READ_SERIAL1 0x640000A7
#define READ_SERIAL2 0x680000AD
//******************************************************************/
// 选择BANK /
//******************************************************************/
#define READ_CURRENT_BANK 0x7C0000B3
#define SWITCH_TO_BANK_0 0xFC000073 // 默认，读bank1后自动返回
#define SWITCH_TO_BANK_1 0xFC00016E
/*********************************************************************
* API FUNCTIONS
*/
void SCL3300_Init(void);
void SCL3300_Test(void);
float SCL3300_ReadAngle(uint8_t direction);
#endif /* _BOARD_SCL3300_H_ */
Five, initialization process
Wait for 10ms after power-on -> set measurement mode -> wait for 5ms -> read status -> enable angle output.
Six, inclination conversion formula
Seven, API call
Need to include the header file board_scl3300.h
SCL3300_Init
| Features | SCL3300 initialization function |
|---|---|
| Function definition | void SCL3300_Init(void) |
| parameter | no |
| return | no |
SCL3300_Test
| Features | Check SPI communication, the third byte of the return value is 0xC1, then the communication is normal |
|---|---|
| Function definition | void SCL3300_Test(void) |
| parameter | no |
| return | no |
SCL3300_ReadAngle
| Features | Reading angle |
|---|---|
| Function definition | float SCL3300_ReadAngle(uint8_t direction) |
| parameter | direction: the direction X, Y, Z axis to be read |
| return | Number of angles |
8. Examples of use
8.1 Initialization
1) Add header files
#include "board_scl3300.h"
#include "board_spi.h"
2) Add initialization code (in the main function of main.c)
/**@brief Function for application main entry.
*/
int main(void)
{
bool erase_bonds;
/*-------------------------- 外设驱初始化 ---------------------------*/
// Initialize.
log_init(); // 日志驱动初始化
timers_init(); // 定时器驱动初始化（在此加入自定义定时器）
SPI_Init(); // SPI驱动初始化
SCL3300_Init(); // SCL3300三轴倾角驱动初始化
···
···
/*-------------------------- 开启应用 ---------------------------*/
// Start execution.
NRF_LOG_INFO("Template example started.");
···
}
8.2 Reading angle
float angX = SCL3300_ReadAngle(ANG_X);
NRF_LOG_INFO("X:" NRF_LOG_FLOAT_MARKER , NRF_LOG_FLOAT(angX));
float angY = SCL3300_ReadAngle(ANG_Y);
NRF_LOG_INFO("Y:" NRF_LOG_FLOAT_MARKER , NRF_LOG_FLOAT(angY));
float angZ = SCL3300_ReadAngle(ANG_Z);
NRF_LOG_INFO("Z:" NRF_LOG_FLOAT_MARKER "\n", NRF_LOG_FLOAT(angZ));
Nine, measurement direction
• Written by Leung on October 26, 2020
• Reference: High-precision three-axis accelerometer SCL3300 drive code