Question

Hello there,

Please help with an example of how to interpret or implement into algorithm the FMT100 values io258 ad io259 (Advanced Eco Driving).

I have read the documentation that the element stores the values of all axis into 16 Byte string in mg but so far I am not being able to extract any human readable value.

here are the real readings of one of my FMT100 devices during Hard Acceleration Event:

io258 = 279692572557451

io259 = 280066230321162

Please explain the method behind it.

Many thanks,

Hristo

Answer 1

Hello,

Avl 258 and 259 schould be in HEX format, their interpretation is on Wiki:

If your 258 decimal value is 279692572557451 which converted to Hex is 0000FE61006F008B

First two bytes zeros: 0000

next 2 bytes: FE61 - X axis in mg, FE61 Hex is 65121 dec, so X axis is 65121

next 2 bytes: 006F - Y axis in mg, 006F Hex is 111 dec

next 2 bytes: 008B - Z axis in mg, 008B Hex is 139 dec

Avl 259 similary

Regards

Comments

Bigger picture:

---

Thank you for you answer, it certainly clears the picture but one question remains.

If the result is in mg, how could I have possibly have survived acceleration of 65.121g ?

Shouldn't the decimal value be negative because it is an Acceleration along the X axis?

Still slightly confused though...

---

Hello

Value 65g could be because accelerometer is not calibrated, please check accelerometer calibration, here is a link to instruction on Wiki:

https://wiki.teltonika-gps.com/view/FMT100_Accelerometer_Features_settings

Regards

---

It is a signed 2B number eg 0xFF85 = -123