cannot pair or advertise HID profile once I toggle gpio pin no. 25 or 26 of nRF52832_WLCSP

[Idan]

To whom it may concern,

I use a BLE app via nRF52832_WLCSP, 'ble_app_hids_keyboard' of SDK11(pca10040),SD s132_nrf52_2.0.0, with the HID profile. once I started advertising BLE and then I toggle gpio pin no. 25 or 26 as a SPI 'chip select' outputs for peripherals(accelerometers) I cannot pair with my central(IOS or Android phones). BLE scanner apps do not show any signs of receiving RSSI data. I must use these exact gpio pins. other gpio pin like 27 or 17 cause nothing alike.

If I start advertising BLE, pair and then I toggle these gpio pins; I can transmit data without any problem noticed.

In the past I used the same app with 'nRF52832_QFN48' I encountered no such problem.

What might be wrong?

Idan

[Hung Bui]

@Idan: I suspect for some reason the chip crashed. Have you check if it's still operate ? any assertion ? You can have a look at this guide for debugging here.

[Idan]

I use the SPI for three other accelerometers with other CS's. they work great, including advertising and leds lightning. it is written in the user manual that: "Radio performance parameters, such as sensitivity, may be affected by high frequency digital I/O with large sink/source current close to the radio power supply and antenna pins.". we used the gpio pins - 25 and 26 as recommended for nRF52832_WLCSP: B3 P0.25 D3 P0.26

and other gpio pins as CS's that works well with advertising: B4 P0.27 A4 P0.29 H2 P0.18

the problematic IO's are not located next to the NFC or radio IO's.