BLE demo with UART not working

RE: BLE demo with UART not working

awneil — Fri, 04 Jun 2021 11:31:17 GMT

[quote userid="104149" url="~/f/nordic-q-a/75923/ble-demo-with-uart-not-working/313609#313609"]RxD is set to RX_PIN_NUMBER = 8, so this is P0.08, right ?
and TX pin number is 6, so P0.06, right ?
[/quote]

Yes.

[quote userid="104149" url="~/f/nordic-q-a/75923/ble-demo-with-uart-not-working/313609#313609"]I assume its correct to cross connect Nordic:RxD <> CP2102:TxD and Nordic TxD <> CP2102 RxD ?[/quote]

Almost certainly, but check the datasheets:

The UART output from the nRF needs to go to the UART input of the CP2102;
The UART input to the nRF needs to come from to the UART output of the CP2102.

[quote userid="104149" url="~/f/nordic-q-a/75923/ble-demo-with-uart-not-working/313609#313609"]Is it necessary to wire RTS/CTS in any way[/quote]

It depends:

does your code implement flow control?
does whatever's connected to the CP2102 require flow control?

RE: BLE demo with UART not working

awneil — Fri, 04 Jun 2021 11:27:33 GMT

[quote userid="104149" url="~/f/nordic-q-a/75923/ble-demo-with-uart-not-working/313605#313605"]its only this line : 181 : APP_ERROR_CHECK(err_code);[/quote]

Well, of course it is - that's the line that catches & throws the error

What you need to look at is the lines immediately before that - what is it which gives that error_code ?

And then look-up that function's documentation - that will tell you the reasons why it might return an error code of 4.

RE: BLE demo with UART not working

MDF — Fri, 04 Jun 2021 10:32:30 GMT

I tried in the meanwhile the ble_app_uart example - I can connect over BLE, but see no data. I'm using a CP2102 serial USB chip to connect to my windows PC as virtual COM7 with putty.

From the defines in pca10040.h : RxD is set to RX_PIN_NUMBER = 8, so this is P0.08, right ?
and TX pin number is 6, so P0.06, right ?
I assume its correct to cross connect Nordic:RxD <> CP2102:TxD and Nordic TxD <> CP2102 RxD ?
Is it necessary to wire RTS/CTS in any way ?

RE: BLE demo with UART not working

MDF — Fri, 04 Jun 2021 10:25:56 GMT

its only this line : 181 : APP_ERROR_CHECK(err_code);
the file app_timer2.c is the original from the SDK

RE: BLE demo with UART not working

awneil — Fri, 04 Jun 2021 09:35:20 GMT

sorry - I meant show us the C source code.

RE: BLE demo with UART not working

MDF — Fri, 04 Jun 2021 09:33:48 GMT

error_code = 4

RE: BLE demo with UART not working

awneil — Fri, 04 Jun 2021 09:19:24 GMT

[quote userid="104149" url="~/f/nordic-q-a/75923/ble-demo-with-uart-not-working/313579#313579"]<error> app: ERROR 4 [NRF_ERROR_NO_MEM] at F:\Keil\nRF5_SDK_17.0.2_d674dde\components\libraries\timer\app_timer2.c:181[/quote]

So what is the code at app_timer2.c: line 181 ?

[quote userid="2111" url="~/f/nordic-q-a/75923/ble-demo-with-uart-not-working/313376#313376"]Seems much like an assert, likely due to framing error on the uart[/quote]

And the SDK has been known to misleadingly give NRF_ERROR_NO_MEM for UART framing errors:

https://devzone.nordicsemi.com/f/nordic-q-a/41480/multiperipheral-nus-crashes/161677#161677

😞

RE: BLE demo with UART not working

MDF — Fri, 04 Jun 2021 09:08:50 GMT

I build with Debug and I also switched to another Hardware board (UTO-NBL-42a) - its a small breakout board - to eliminate any possible issue with the MSP430

Without "uart_init" the debug terminal output is like this, just fine

Starting..
<info> app_timer: RTC: initialized.
<info> app: m_whitelist_peer_cnt 2, MAX_PEERS_WLIST 8
<info> app: Fast advertising with whitelist.
<info> app: Slow advertising with whitelist.

With "uart_init" is see this

Starting..
UartInit
<info> app_timer: RTC: initialized.
<info> app_timer: RTC: initialized.
<info> app: m_whitelist_peer_cnt 2, MAX_PEERS_WLIST 8
<info> app: Fast advertising with whitelist.
<error> app: ERROR 4 [NRF_ERROR_NO_MEM] at F:\Keil\nRF5_SDK_17.0.2_d674dde\components\libraries\timer\app_timer2.c:181
PC at: 0x00028427

After the first "RTC initialized" it takes approx 20 secs, then I see the 2nd "RTC initialised" and the error in app_error_fault_handler() with ID=0x4001

APP_UART_FIFO_INIT returns =8, but according to some other posts, I assume this is ok

I added a 10 kOhm resistor to Uart RX (P0.08) but see no change either.

RE: BLE demo with UART not working

Kenneth — Thu, 03 Jun 2021 11:20:51 GMT

[quote user=""]Led goes solid on and I'm not able to connect to the device in any way.[/quote]

Seems much like an assert, likely due to framing error on the uart, if you build with Debug (not Release) you should get some more information from your fault_handler (typically app_error_fault_handler()).

Can you for quick test just try to add a 10kohm pull up on the UART RX pin?

RE: BLE demo with UART not working

awneil — Wed, 02 Jun 2021 15:56:18 GMT

have you checked what error code is returned?

Does this help: https://acassis.wordpress.com/2016/06/26/how-i-got-fooled-by-nordics-app_uart_init/ ?