User register memory map

[raess1]

adi_driver/src/adis16470.cpp

Lines 340 to 341 in d420899

	read_register(0x04, gyro_low[0]);
	read_register(0x06, gyro_low[0]);

Why is gyro_low referenced twice?

Looking in the User register memory map in 16470 datasheet
It looks like this:

X_GYRO_LOW 0x04
X_GYRO_OUT 0x06
Y_GYRO_LOW 0x08
Y_GYRO_OUT 0x0A
Z_GYRO_LOW 0x0C
Z_GYRO_OUT 0x0E
X_ACCL_LOW 0x10
X_ACCL_OUT 0x12
Y_ACCL_LOW 0x14       
Y_ACCL_OUT 0x16
Z_ACCL_LOW 0x18
Z_ACCL_OUT 0x1A

TEMP_OUT  0x1C               

[7675t]

It may be misleading, but read_register() is an SPI communication. It send an address to read, but we can get actual value in the next read. So the first read_register() return meaningless value, and actual gyro_low[0] is received the next read_register(0x06, gyro_low[0]); call. That's also why the last read_register(0x00, temp_out); returns TEMP_OUT value (0x00 is a kind of NOP command).

[raess1]

thanks for the reply! Just tested it for 16465-1 and seems to work good.

This changes are made for 16465-1, 16465-2 and 16465-3

  //ADIS16465-1, 32-bit GYROSCOPES Sensitivity 10,485,760 LSB/°/sec
   gyro[i] = ((int32_t(gyro_out[i]) << 16) + int32_t(gyro_low[i])) * M_PI / 180.0 / 10485760.0;
   accl[i] = ((int32_t(accl_out[i]) << 16) + int32_t(accl_low[i])) * 9.8 / 262144000.0;
   
   //ADIS16465-2, 32-bit GYROSCOPES Sensitivity 2,621,440 LSB/°/sec
   /*
   gyro[i] = ((int32_t(gyro_out[i]) << 16) + int32_t(gyro_low[i])) * M_PI / 180.0 / 2621440.0;
   accl[i] = ((int32_t(accl_out[i]) << 16) + int32_t(accl_low[i])) * 9.8 / 262144000.0;
   */
   
   //ADIS16465-3, 32-bit GYROSCOPES Sensitivity 655,360 LSB/°/sec
    /*
   gyro[i] = ((int32_t(gyro_out[i]) << 16) + int32_t(gyro_low[i])) * M_PI / 180.0 / 655360 .0;
   accl[i] = ((int32_t(accl_out[i]) << 16) + int32_t(accl_low[i])) * 9.8 / 262144000.0;
   */