AMS_AS5600
前言
A position sensor is a sensor that facilitates measurement of mechanical position.
The AS5600 is an easy to program magnetic rotary position sensor with a high-resolution 12-bit analog or PWM output. The AS5600 is also equipped with a smart low power mode feature to automatically reduce the power consumption.
Design Note
AS5600有部分硬體設置重點，第一點是磁鐵選用，磁體尺寸盡可能是圓形因為他是感受磁場垂直變化(尺寸規範如下)
且這邊注意磁鐵是使用對稱
第二點在裝置上也不能偏移太多，下圖是偏移對磁場變化影響圖與實際規範範圍圖，可以看到雖然是有容許裝置範圍但不可無限制偏移
Coding Sample
這邊選用I2C來做為範例可以先參考下圖Register map
I2C傳輸
這邊只需要注意它的部分傳輸是分2筆，每筆DATA 8Bit因此在讀完整Data時與一般SPI不同是分2個register讀取
uint16_t readTwo_register(uint8_t Sensor_register)
{
int highByte = read_register(Sensor_register );
int lowByte = read_register(Sensor_register+1);
return ( highByte << 8 ) | lowByte;
};
uint8_t read_register(uint8_t Sensor_register)
{
HAL_StatusTypeDef status;
uint8_t return_value = 0;
status = HAL_I2C_Mem_Read(&hi2c1,ams5600_Address ,Sensor_register, I2C_MEMADD_SIZE_8BIT, &return_value, 1, 100);
HAL_Delay(10);
/* Check the communication status */
if(status != HAL_OK)
{
printf("I2C read status error =%#x \n\r",status);
/*
HAL_ERROR = 0x01U,
HAL_BUSY = 0x02U,
HAL_TIMEOUT = 0x03U
*/
}
return return_value;
};
void write_register(uint8_t Sensor_register, uint8_t register_value)
{
HAL_StatusTypeDef status = HAL_OK;
status = HAL_I2C_Mem_Write(&hi2c1,ams5600_Address , Sensor_register, I2C_MEMADD_SIZE_8BIT, ®ister_value,1, 100);
HAL_Delay(10);
/* Check the communication status */
if(status != HAL_OK)
{
printf("I2C write status error =%#x \n\r",status);// Error handling, for example re-initialization of the I2C peripheral
}
}
讀取角度
這部分就比較簡單單純讀取出來換算而已，至於其他功能可以做切換輸出模式等等可以再額外設定
uint16_t getRawAngle()
{
return readTwo_register(addr_raw_angle);
}
float convertRawAngleToDegrees(uint16_t newAngle)
{
/* Raw data reports 0 - 4095 segments, which is 0.087 of a degree */
float retVal = newAngle * 0.087;
return retVal;
}
總結
AS5600是使用在低轉速馬達控制PTZ等，很方便使用，也可以及時偵測磁鐵強度訊號和切換輸出，算一個CP質非常高感測器