PGA460: Distance Calculation

Hi Kato-san,

UART Command 5 in Table 3 shows that Bytes 1-2 are the MSB and LSB bytes of the object time of flight in microseconds. The time of flight value is a 16-bit value, so the MSB and LSB 8-bit bytes must be concatenated to create the 16 bit value. This is why the 8-bit left shift is applied in the conversion to distance equation.

For example, if UART Command 5 returns the following values for one object: 0x{40,1B,62,23,68,B6}, then the raw values are:

• 0x40 is the diagnostic byte
• 0x1B is the echo time of flight MSB
• 0x62 is the echo time of flight LSB
• 0x23 is the echo width
• 0x68 is the echo amplitude
• 0xB6 is the checksum

Whereby the time of flight in microseconds is 0x1B62 = 7010us --> 1.2m in distance.