M8U losing calibration/cold starting every time.

Qwiic System
1

I used the M8U BOB to take data from MI to SC. Driving 7 to 8 hours per day.

Did not move or uninstall the module at the end of the day but every day the sensor alignment was in init mode and you can not calibrate the alignment just driving down the freeway.

Why do I keep losing calibration?

In the beginning, if I did not move the module the next start up was in dead reckoning mode.

What changed?

Battery not charging?

Any thoughts?

Thanks

Bruce

2

Thanks for reaching out to us on this.

It sounds like to coin-cell battery on the board has failed;

16329-SparkFun_GPS_Dead_Reckoning_Breakout_-_NEO-M8U__Qwiic_-01.jpg600×600 94.3 KB
https://cdn.sparkfun.com//assets/parts/ … ic_-01.jpg upper left corner, replace it with another 3v 1mAh

Another option is to change the settings to save your config to flash memory; the datahseet mentions:

"Settings stored in Flash memory will remain effective even after power-down and do not require

backup battery supply."

Swapping that might also accomplish the goal. Hope this helps, and happy sparking!

3

Save on shut down will do that but how do I do that without on external flash? I do not think the board has external flash does it?

I can save the Yaw/pitch/roll offsets to an EEPROM but the library does not include the message to set them on power on…

Any suggestions on a part #/type for the batter?

Thanks

Bruce

4

ML414H IV01E is a $1.89 part that I have to unsolder from a $70+ dollar board without messing up other surface mount devices.

And if I do screw it up when what? Buy a $70+ new board because of a new $1.89 battery? Doesn’t there seem to be something wrong with the intended design of this is the only way to replace a battery that can fail? just aske my phone…

Does not seem to be a good way to design it?

Thank

5

We appreciate the input.

Head on over to https://www.sparkfun.com/returns and we can refund you once we receive the returned product.

6

Head over to that page and we’ll get you squared away.

7

I just gotten my M8U and the calibration cannot be retained and the GPS lock is via cold start. what should I do now? change the battery? shipping back to US seems more expensive.