Writing SOFTDEVICE makes signal width increases

[pump20]

Runtime environment:

1.IC:52840QIAA；

2.SOFTDEVICE:s140_nrf52840_5.0.0-2.alpha_softdevice.hex

 

Development:

1. PWM signals of 10 groups of adjustable frequency and width in 30 channels IO output.
2. Adjustment range: frequency 1～120Hz, width 50～400us.

 

Result:

1. Without writing SOFTDEVICE, frequency and width of 10 groups of output are stable.
2. After writing SOFTDEVICE, frequency  of 10 groups of output is stable, but when we tested random IO output signal, we found width would increase less than 100us.

Video 1: After writing SOFTDEVICE, pulse width is changing when Bluetooth is working;

Video 2: Without writing SOFTDEVICE, pulse width is accurate and stable when 52840 is working only as SCM.

[bjorn-spockeli]

Hi, 

Could you provide the full chip marking? (e.g. N52840 QIAACA 1803AA) I would like to know if you're using an engineering version or not. 

Also you are using a Alpha version of the S140 SoftDevice, I strongly recommend moving to the production version, i.e. S140 v6.0.0. The same applies to the SDK version, i.e. SDK v15.0.0. 

Best regards

Bjørn 

[pump20]

We’ve tested SoftDevice V6.0.0. Problem is still there until we used redio notify which was debugged with Application control. Is there any better solution?

[bjorn-spockeli]

Could you provide the full chip marking? (e.g. N52840 QIAACA 1803AA) I would like to know if you're using an engineering version or not. 

In addition I would like to know if you are using the PWM library or the PWM Driver to generate the PWM pulses?