BLE App Uart nRF52810

[berkutta]

I'm trying to get the ble_app_uart example working on a nRF52810. I'm using SDK 15.2.0 together with Softdevice S112.

The infocenter says the Example needs Softdevice S132 or S140 http://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.sdk5.v15.2.0%2Findex.html. But that's not available for nRF52810. So what's the solution to run the ble_app_uart demo on the nRF52810?

If I try to use the ble_app_uart on the nRF52810 with the pca10040e then it doesn't work. I don't get UART output and also don't see any UART device with the nRF Connect App.

[Vidar Berg]

Hi,

The pca10040e configuration requires softdevice s112 (\components\softdevice\s112\hex) which will be uploaded automatically if you use Segger Embedded studio. Does you board include a 32kHz crystal? If not, make sure to change the clock source to use the internal RC in sdk_config.h.

//==========================================================

// <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

[berkutta]

Hi,

Thanks for the fast answer. I already did that but it still doesn't work. I'm using arm gcc under Linux. I have also removed the emulation flags in the Makefile.

[Vidar Berg]

Hi,

I would suggest that you debug the code, see if the program reaches main() for instance. You may use Segger embedded studio for debugging if you don't have a different debug setup. Also, since you have a custom board, note that the code enables pinreset on P0.21 by default (is active low).

[berkutta]

Hi,

Thanks! The Reset Pin was the issue, it's now working! What I don't understand is, if I understand correctly the -DCONFIG_GPIO_AS_PINRESET flag enables this feature. But that's also enabled on the ble_app_beacon example. But the beacon example is working without hooking up P0.21 to VCC.

[berkutta]

hmm, it's a bit strange. I have disabled the -DCONFIG_GPIO_AS_PINRESET, erased the chip and reflashed everything. But the reset seems to be still active. My Hardware leaves P0.21 floating

The PSELRESET register looks like that:

nrfjprog -f NRF52 --memrd 0x10001200 --n 8          
0x10001200: FFFFFFFF FFFFFFFF                     |........|

[Vidar Berg]

Pinreset should not have been triggered if  P0.21 was left floating. I suspect the actual issue is floating RX input: https://devzone.nordicsemi.com/f/nordic-q-a/40625/app_ble_uart-uart-must-be-hooked-up

[berkutta]

Hi,

Yep, I can confirm that this was the root issue. I thought it's resetting due to P0.21 but I was also unintentionally touching RX with my hands (and thus causing the APP_UART_COMMUNICATION_ERROR event). With enabling the Pullup or disabling the UART module it's fixed.

Thanks for the first class support Vidar Berg