Issue with Sensor data from MPU-9250 #505

New Issue

MrUnknownDE · 2026-04-05T17:53:06+02:00

MrUnknownDE commented

2026-04-05 17:53:06 +02:00

Originally created by @ThePheonixGuy on 8/8/2021

Hello Again!

I've been trying to set up some trackers of my own with this.
I have gotten to a point where its mostly stable for one sensor, for a while (+- 5 minutes). However, all other sensors after a short time (within a few seconds) start reporting "NaN NaN NaN" for their rotation value.

I've run a short sketch on my esp's to ensure the MPU's are wired and configured correctly - and they are, showing data across the range.

I added some debug print lines to the MPU9250Sensor::getMPUScaled() call to show me the raw data, and then another to show me what gets sent over the wire.

This results in values like such:

[DEBUG] Sent data: -0.00,39145.87,32490.37RM, 0.00,0.00,1.00A, -0.00,0.77,0.64M, nan,nan,nanQ.
[DEBUG] Raw data: 32767,32767,-3476A, -308,-243,-1429G, -129,-129,27890M
[DEBUG] Sent data: -0.00,61243.93,54674.87RM, 0.00,0.00,1.00A, -0.00,0.75,0.67M, nan,nan,nanQ.
[DEBUG] Raw data: 32767,32767,-3532A, -178,-211,-1414G, -129,-129,13554M
[DEBUG] Sent data: -0.00,33119.12,26440.05RM, 0.00,0.00,1.00A, -0.00,0.78,0.62M, nan,nan,nanQ.
[DEBUG] Raw data: 32767,32767,-3524A, -130,-236,-1419G, -129,-129,15602M
[DEBUG] Sent data: -0.00,37136.96,30473.60RM, 0.00,0.00,1.00A, -0.00,0.77,0.63M, nan,nan,nanQ.
[DEBUG] Raw data: 32767,32767,-3600A, -296,-218,-1411G, -129,-129,-3855M
[DEBUG] Sent data: 0.00,-1034.39,-7847.05RM, 0.00,0.00,1.00A, 0.00,-0.13,-0.99M, nan,nan,nanQ.
[DEBUG] Raw data: 32767,32767,-3688A, -339,-224,-1399G, -129,-129,-26383M
[DEBUG] Sent data: 0.00,-45230.51,-52216.04RM, 0.00,0.00,1.00A, 0.00,-0.65,-0.76M, nan,nan,nanQ.
[DEBUG] Raw data: 32767,32767,-3604A, -150,-230,-1350G, -129,-129,-4879M
[DEBUG] Sent data: 0.00,-3043.31,-9863.82RM, 0.00,0.00,1.00A, 0.00,-0.29,-0.96M, nan,nan,nanQ.
[DEBUG] Raw data: 32767,32767,-3636A, -195,-219,-1436G, -129,-129,-13071M
[DEBUG] Sent data: 0.00,-19114.62,-25998.00RM, 0.00,0.00,1.00A, 0.00,-0.59,-0.81M, nan,nan,nanQ.
[DEBUG] Raw data: 32767,32767,-3624A, -335,-229,-1390G, -129,-129,-9999M
[DEBUG] Sent data: 0.00,-13087.88,-19947.68RM, 0.00,0.00,1.00A, 0.00,-0.55,-0.84M, nan,nan,nanQ.

Any ideas? Again - checked the sensor with another sketch to ensure it is working and all are working perfectly fine.

I'm just not smart enough / clued up enough to understand the Quaternion maths that goes into translating the raw sensor values.

*Originally created by @ThePheonixGuy on 8/8/2021* Hello Again! I've been trying to set up some trackers of my own with this. I have gotten to a point where its mostly stable for one sensor, for a while (+- 5 minutes). However, all other sensors after a short time (within a few seconds) start reporting "NaN NaN NaN" for their rotation value. I've run a short sketch on my esp's to ensure the MPU's are wired and configured correctly - and they are, showing data across the range. I added some debug print lines to the MPU9250Sensor::getMPUScaled() call to show me the raw data, and then another to show me what gets sent over the wire. This results in values like such: ```[DEBUG] Raw data: 32767,32767,-3520A, -221,-256,-1370G, -129,-129,16626M [DEBUG] Sent data: -0.00,39145.87,32490.37RM, 0.00,0.00,1.00A, -0.00,0.77,0.64M, nan,nan,nanQ. [DEBUG] Raw data: 32767,32767,-3476A, -308,-243,-1429G, -129,-129,27890M [DEBUG] Sent data: -0.00,61243.93,54674.87RM, 0.00,0.00,1.00A, -0.00,0.75,0.67M, nan,nan,nanQ. [DEBUG] Raw data: 32767,32767,-3532A, -178,-211,-1414G, -129,-129,13554M [DEBUG] Sent data: -0.00,33119.12,26440.05RM, 0.00,0.00,1.00A, -0.00,0.78,0.62M, nan,nan,nanQ. [DEBUG] Raw data: 32767,32767,-3524A, -130,-236,-1419G, -129,-129,15602M [DEBUG] Sent data: -0.00,37136.96,30473.60RM, 0.00,0.00,1.00A, -0.00,0.77,0.63M, nan,nan,nanQ. [DEBUG] Raw data: 32767,32767,-3600A, -296,-218,-1411G, -129,-129,-3855M [DEBUG] Sent data: 0.00,-1034.39,-7847.05RM, 0.00,0.00,1.00A, 0.00,-0.13,-0.99M, nan,nan,nanQ. [DEBUG] Raw data: 32767,32767,-3688A, -339,-224,-1399G, -129,-129,-26383M [DEBUG] Sent data: 0.00,-45230.51,-52216.04RM, 0.00,0.00,1.00A, 0.00,-0.65,-0.76M, nan,nan,nanQ. [DEBUG] Raw data: 32767,32767,-3604A, -150,-230,-1350G, -129,-129,-4879M [DEBUG] Sent data: 0.00,-3043.31,-9863.82RM, 0.00,0.00,1.00A, 0.00,-0.29,-0.96M, nan,nan,nanQ. [DEBUG] Raw data: 32767,32767,-3636A, -195,-219,-1436G, -129,-129,-13071M [DEBUG] Sent data: 0.00,-19114.62,-25998.00RM, 0.00,0.00,1.00A, 0.00,-0.59,-0.81M, nan,nan,nanQ. [DEBUG] Raw data: 32767,32767,-3624A, -335,-229,-1390G, -129,-129,-9999M [DEBUG] Sent data: 0.00,-13087.88,-19947.68RM, 0.00,0.00,1.00A, 0.00,-0.55,-0.84M, nan,nan,nanQ. ``` Any ideas? Again - checked the sensor with another sketch to ensure it is working and all are working perfectly fine. I'm just not smart enough / clued up enough to understand the Quaternion maths that goes into translating the raw sensor values.

MrUnknownDE closed this issue

2026-04-05 17:53:06 +02:00

Sign in to join this conversation.

1 Participants

Notifications

Due Date

No due date set.

Dependencies

No dependencies set.

Reference: github/SlimeVR-Tracker-ESP#505