nrf_asset_tracker_v2 thingy91 accelerometer movement detection failed

[DevNetNow]

Hi 

testing with thingy91 v1.4.0, firmware 1.5.1.

I never succeeded to enable passive mode of nrf_asset_tracker_v2 no acceleration is detected. 

Someone experience the same issue?  

[DevNetNow]

Hi ,

back with update,

There is two use cases with different behaviors : 

Use case 1: External active GPS antenna disconnected

Following line in board_nonsecure.c file : 

#define AT_CMD_COEX0 "AT%XCOEX0=1,1,1565,1586" 

Then accelerometer and movement detection in passive mode OK, but no GPS position fix (very poor signal reception). 

Use case 2: External active GPS antenna connected

Following line in board_nonsecure.c file :  

#define AT_CMD_COEX0 "AT%XCOEX0" 

Then accelerometer and movement detection in passive mode stops working, with decent GPS position fix (better signal reception). 

I didn't see any hardware link of COEX0 and accelerometer signals... 

Any workarround is welcome 

Regards  

[DevNetNow]

Hello,

After some digging, i just found that the whole system work perfectly with external power bank, or when USB is plugged. 

I'll do more tests with the power profiler. 

the problem is the PMIC, any added external power consumer need a PMIC with higher specs. 

may be my antenna is current hangry, i'll try with another antenna. 

[Øyvind]

Glad to hear that it's working!

[DevNetNow]

Hello,

I found the issue origin, but still my problem is not solved. there is no way to put a power bank next to the final product. If external 5V powering is needed all the time, there is no reason to put a battery.  

I need to redesign my custom board with another PMIC, i choosed the ADP5360 for quick design convenience). 

Meanwhile, i just noticed that thingy91 v1.6.0 have power management improvements. Here is the change log "Power optimization, added circuitry to turn off RF switches when not used "

When we look at the design deltas : 

v1.6.0 : 

v1.4.0 

i suppose i'm not the first one experiencing issues with COEX and power signals managements. 

I ordered recently from mouser they still have the version 1.4.0 stocked. so i can't test if the issue is resolved in v1.6.0. 

i'm wondering if it worth a try with the modified design like in v1.6.0.

i would love to hear from hardware guys with more detailed reasons of this hardware change?

do they experience voltage drops when external antenna is plugged like in my case ? 

do they still advice usign ADP5360 for custom designs and additional  power consumers ? 

Thanks for your feedback. 

[Øyvind]

Sounds like you should have a design review by one of our HW experts. Please open a new ticket for HW design.

Kind regards,
Øyvind 

[DevNetNow]

i'm testing with the thingy91, my own design is a copy of it. then i'll add customs from a working base.

Yes a hardware advice is needed 

Regards