Different behavior with two different nrf52dk boards

[bb_elaDial]

SDK version 2.4.0

toolchains version 2.4.0  

When try to run the Bluetooth: Peripheral UART Example on out of the box nrf52dk-nrf52832 dev boards (Two different dev boards) I get different outputs on RTT

on one board (lets called it Board "A") example is working as expected. means I can send and received data via UART. I use nrf connect on ios as central

below is the output from the RTT viewer 

00> [00:00:00.015,136] <inf> fs_nvs: 6 Sectors of 4096 bytes
00> [00:00:00.015,197] <inf> fs_nvs: alloc wra: 0, fd0
00> [00:00:00.015,228] <inf> fs_nvs: data wra: 0, 1c
00> [00:00:00.015,472] <inf> bt_sdc_hci_driver: SoftDevice Controller build revision:
00> e0 7e 2e c1 5e 05 85 23 46 15 dc fa 8e 29 7d 70 |.~..^..# F....)}p
00> 10 93 a5 fc |....
00> [00:00:00.020,996] <inf> bt_hci_core: HW Platform: Nordic Semiconductor (0x0002)
00> [00:00:00.021,087] <inf> bt_hci_core: HW Variant: nRF52x (0x0002)
00> [00:00:00.021,118] <inf> bt_hci_core: Firmware: Standard Bluetooth controller (0x00) Version 224.11902 Build 2231721665
00> [00:00:00.022,033] <inf> bt_hci_core: No ID address. App must call settings_load()
00> [00:00:00.022,064] <inf> peripheral_uart: Bluetooth initialized
00> [00:00:00.023,284] <inf> bt_hci_core: Identi0m
00> [0m
00> [00:00:14.753,295] <inf> peripheral_uart: Connected 60:F2:57:81:71:A7 (random)
00> [00:00:15.077,728] <wrn> bt_l2cap: Ignoring data for unknown channel ID 0x003a
00> [00:00:27.836,364] <inf> peripheral_uart: Received data from: 60:F2:57:81:71:A7 (random)
00> [00:00:37.537,353] <inf> peripheral_uart: Received data from: 60:F2:57:81:71:A7 (random)

when I flash the other dev kit (Lets call this Board "B") with same hex, I'm getting the following out put when tried to received/transmit data

00> [00:00:00.015,319] <inf> fs_nvs: 6 Sectors of 4096 bytes
00> [00:00:00.015,380] <inf> fs_nvs: alloc wra: 0, fd0
00> [00:00:00.015,411] <inf> fs_nvs: data wra: 0, 1c
00> [00:00:00.015,655] <inf> bt_sdc_hci_driver: SoftDevice Controller build revision:
00> e0 7e 2e c1 5e 05 85 23 46 15 dc fa 8e 29 7d 70 |.~..^..# F....)}p
00> 10 93 a5 fc |....
00> [00:00:00.021,392] <inf> bt_hci_core: HW Platform: Nordic Semiconductor (0x0002)
00> [00:00:00.021,453] <inf> bt_hci_core: HW Variant: nRF52x (0x0002)
00> [00:00:00.021,514] <inf> bt_hci_core: Firmware: Standard Bluetooth controller (0x00) Version 224.11902 Build 2231721665
00> [00:00:00.022,430] <inf> bt_hci_core: No ID address. App must call settings_load()
00> [00:00:00.022,491] <inf> peripheral_uart: Bluetooth initialized
00> [00:00:00.023,742] <inf> bt_hci_core: Identi0m
00> [0m
00> [00:06:01.252,380] <inf> peripheral_uart: Connected 60:F2:57:81:71:A7 (random)
00> [00:06:01.549,774] <wrn> bt_l2cap: Ignoring data for unknown channel ID 0x003a
00> [00:06:27.959,472] <wrn> peripheral_uart: Failed to send data over BLE connection
00> [00:06:30.702,789] <wrn> peripheral_uart: Failed to send data over BLE connection

 

Rather than calling this a hardware issue and moved on, I would like to know why that the board B is partially functioning with Bluetooth stack. 

I tried following troubleshooting steps 

 

1. use nrf connect desktop programmer to read back the chip and compare the address regions - comparison is identical 

2. use nrf52840dk to run Central UART example - results are identical to above except both boards are using security level 2

3. perform Mass Erase before reprogramming  - same results as above 

Any explanation/opinion , troubleshooting steps are much appreciated  

Thanks 

[Priyanka]

Hi,

Could you tell me the revisions of both the boards?

Best Regards,

Priyanka

[bb_elaDial]

Hi 

Both boards have same rev information as followed 

3.0.0

2023.4

[Priyanka]

Hi,

Could you try a simple sample, say, hello_world or blinky and see whether there is a difference in implementation on both boards?

Regards,

Priyanka

[bb_elaDial]

Hi Priyanka, 

I tried the following examples, and they are working as expected on both boards.

-hello world 

- blinky

-blinky PWM 

[Priyanka]

That looks strange, because then you have the difference only when you run the peripheral UART sample? And both boards have no peripherals or anything connected to them right? i.e., the hardware for both boards are the same?

-Priyanka

[bb_elaDial]

Hi Priyanka

anything that has nothing to do with Bluetooth, seems to work identically on both boards. let me try to run Zephyr Bluetooth HT example. And central on faulty board.      

[Priyanka]

Hi,

Were you able to run the Bluetooth HT sample?

-Priyanka