NRF52840 data communication issue with 20 msec delay

RE: NRF52840 data communication issue with 20 msec delay

jagadeesh surneni — Thu, 13 Jun 2019 08:25:30 GMT

hello kenneth,

now i am able to transmit 500 bytes of data from slave to master with 100 ms time period. but its working upto 10 meters range . we want it up to 80 meters range.we are using (#define TX_POWER_LEVEL 8) max level. after 10 meters range board is unable to pair and reconnect. To solve this situation i have implemented watchdog timer.but i am facing problems.

can you please help us to resolve the range problem and wdt implementation issue.

Regards,

jagadeesh

RE: NRF52840 data communication issue with 20 msec delay

Kenneth — Mon, 03 Jun 2019 09:03:30 GMT

I think an on-air sniffer trace would be helpful, can you for instance do a trace using nRF Sniffer?

Best regards,
Kenneth

RE: NRF52840 data communication issue with 20 msec delay

jagadeesh surneni — Thu, 30 May 2019 05:22:26 GMT

hello kenneth,

i have tried to change the tolerance to 500 ppm. But still i am facing the same issue.

Regards,

jagadeesh

RE: NRF52840 data communication issue with 20 msec delay

Kenneth — Wed, 29 May 2019 14:33:53 GMT

Please set NRF_SDH_CLOCK_LF_ACCURACY 1

Kenneth

RE: NRF52840 data communication issue with 20 msec delay

jagadeesh surneni — Wed, 29 May 2019 05:25:56 GMT

Hi kenneth,

Master is connected through USB(UART to USB) and slave is connected through RS485(UART to RS485) .

#define APP_ADV_INTERVAL 32

#define SLAVE_LATENCY 0

#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 7
#endif

Best regards,

jagadeesh

RE: NRF52840 data communication issue with 20 msec delay

Kenneth — Mon, 27 May 2019 08:56:41 GMT

Hello,

What is the connection parameters here? What is the interval and slave latency?

What LFCLK source is used and what is the tolerance of the LFCLK when init the softdevice?

An on-air sniffer trace may be useful. I recommend to try to set slave latency = 0 and tolerance to 500ppm for test to see if that improve the situation.

Best regards,
Kenneth