RE: nRF52832 (MDBT42Q module) never has correct Services and Characteristics

mydadisaplumber — Sat, 07 Mar 2020 16:34:27 GMT

Hi Simon. I verified the answer because it worked, but I don't know if it doesn't show up for you anymore. I'm curious at why this could happen with the bonding. Thanks!

RE: nRF52832 (MDBT42Q module) never has correct Services and Characteristics

mydadisaplumber — Wed, 04 Mar 2020 03:44:53 GMT

Hi Simon,

It turned out to be your first suggestion! All I had to do was "forget" the bonding pair to the device, and then it discovered the services as normal!

However, I don't understand how that happened. I did have a different device address, serial number, etc... on this new device. Maybe Android looks at some other property of the BLE peripheral to tie it to a previous bond? But why would it then not enumerate the correct BLE services?

Thanks again!

RE: nRF52832 (MDBT42Q module) never has correct Services and Characteristics

Simonr — Tue, 03 Mar 2020 08:01:18 GMT

I believe this could happen due to a couple of things.

First, does this new module have the same address as your previous PCB? In that case, that might be why you're not able to see the services on this new device. Please try giving it a new address and/or delete the bonding information on your central (I assume this is a phone).

Next, have you included the external LF clock in your design. This is not part of most 3rd party modules (including this one) and our examples are configured to use this LF clock. You can make these changes in the sdk_config.h file in order to configure the chip to use the internal LFRC instead as well. (This does not seem like the symptoms of using an incorrect LF clock though, but I thought I'd add it just in case).

// <h> Clock - SoftDevice clock configuration

//==========================================================
// <o> NRF_SDH_CLOCK_LF_SRC  - SoftDevice clock source.
 
// <0=> NRF_CLOCK_LF_SRC_RC 
// <1=> NRF_CLOCK_LF_SRC_XTAL 
// <2=> NRF_CLOCK_LF_SRC_SYNTH 

#ifndef NRF_SDH_CLOCK_LF_SRC
#define NRF_SDH_CLOCK_LF_SRC 0
#endif

// <o> NRF_SDH_CLOCK_LF_RC_CTIV - SoftDevice calibration timer interval. 
#ifndef NRF_SDH_CLOCK_LF_RC_CTIV
#define NRF_SDH_CLOCK_LF_RC_CTIV 16
#endif

// <o> NRF_SDH_CLOCK_LF_RC_TEMP_CTIV - SoftDevice calibration timer interval under constant temperature. 
// <i> How often (in number of calibration intervals) the RC oscillator shall be calibrated
// <i>  if the temperature has not changed.

#ifndef NRF_SDH_CLOCK_LF_RC_TEMP_CTIV
#define NRF_SDH_CLOCK_LF_RC_TEMP_CTIV 2
#endif

// <o> NRF_SDH_CLOCK_LF_ACCURACY  - External clock accuracy used in the LL to compute timing.
 
// <0=> NRF_CLOCK_LF_ACCURACY_250_PPM 
// <1=> NRF_CLOCK_LF_ACCURACY_500_PPM 
// <2=> NRF_CLOCK_LF_ACCURACY_150_PPM 
// <3=> NRF_CLOCK_LF_ACCURACY_100_PPM 
// <4=> NRF_CLOCK_LF_ACCURACY_75_PPM 
// <5=> NRF_CLOCK_LF_ACCURACY_50_PPM 
// <6=> NRF_CLOCK_LF_ACCURACY_30_PPM 
// <7=> NRF_CLOCK_LF_ACCURACY_20_PPM 
// <8=> NRF_CLOCK_LF_ACCURACY_10_PPM 
// <9=> NRF_CLOCK_LF_ACCURACY_5_PPM 
// <10=> NRF_CLOCK_LF_ACCURACY_2_PPM 
// <11=> NRF_CLOCK_LF_ACCURACY_1_PPM 

#ifndef NRF_SDH_CLOCK_LF_ACCURACY
#define NRF_SDH_CLOCK_LF_ACCURACY 1
#endif

Best regards,

Simon