ble_app_uart + spi only works with connected J-Link

RE: ble_app_uart + spi only works with connected J-Link

awneil — Fri, 25 Jan 2019 15:04:46 GMT

Thanks for the feedback.

For completeness, could you say how that buffer was previously declared?

ie, what was the "wrong" way?

RE: ble_app_uart + spi only works with connected J-Link

5IM00N — Fri, 25 Jan 2019 14:48:23 GMT

Sorry for the late reply. I found my mistake. I declared the TX buffer the wrong way in my other project. So the firmware probably crashed.

Right way:

static uint8_t       m_tx_buf[] = TEST_STRING;           /**< TX buffer. */

Hope this helps someone. And thank to all for the help! :)

RE: ble_app_uart + spi only works with connected J-Link

haakonsh — Mon, 14 Jan 2019 09:20:50 GMT

"My last data command should be 0x12 (1 Byte) but after that I get an additionally byte with 0xFF. In both cases. But this should not be transfered."

I think you're experiencing PAN[58] SPIM: An additional byte is clocked out when RXD.MAXCNT = 1. Check out the workaround described in the errata doc.

RE: ble_app_uart + spi only works with connected J-Link

5IM00N — Fri, 11 Jan 2019 14:05:21 GMT

[quote userid="6462" url="~/f/nordic-q-a/42389/ble_app_uart-spi-only-works-with-connected-j-link/165169"][/quote]

> Are you using a Nordic board, or something else?

I am using the Nordic DK. On my custom PCB the behavior is the same.

> What sensor is it? How is it connected to the board? Are you sure that there is a good ground connection between sensor & board?

I am controlling an e-paper display with 4kByte imagedata.

I'll check the GND connection. I just soldered 10cm of wire between the two devices.

RE: ble_app_uart + spi only works with connected J-Link

5IM00N — Fri, 11 Jan 2019 14:02:53 GMT

[quote userid="6462" url="~/f/nordic-q-a/42389/ble_app_uart-spi-only-works-with-connected-j-link/165169"][/quote]

> What, exactly, do you mean by "connected" ?

With connected I mean that I choose "Target" > "Connect J-Link" in the SES IDE.

If it is disconnected and I choose "Target" > "Download ble_app..." and push the reset button, it stucks in the SPI routine waiting for the slave to respond after 4kByte data transmission. Then, if I connect J-Link and push the reset button again it starts working fine.

> Or do you mean it only works when run under the debugger?

So I think the debugger is running even if I dont step through the code.

> Do you just mean when the cable is physically in place, but the JLink is not in use?

The USB cable is always plugged in.

RE: ble_app_uart + spi only works with connected J-Link

5IM00N — Fri, 11 Jan 2019 13:59:05 GMT

Yes, I did this the signals looks good.

Working (with J-Link connected): The slave needs about 8 seconds to process the data and respond.

Not working (without J-Link connected): The slave could not interpret or process the data. Why does this depend on J-Link?

I just analyzed the last data which was transmitted before it get stuck.

My last data command should be 0x12 (1 Byte) but after that I get an additionally byte with 0xFF. In both cases. But this should not be transfered.

Is there a 16 Bit SPI mode? Or something like that?

RE: ble_app_uart + spi only works with connected J-Link

awneil — Fri, 11 Jan 2019 13:08:49 GMT

[quote userid="76135" url="~/f/nordic-q-a/42389/ble_app_uart-spi-only-works-with-connected-j-link"]It all works fine while the J-Link is connected[/quote]

What, exactly, do you mean by "connected" ?

Do you just mean when the cable is physically in place, but the JLink is not in use?

Or do you mean it only works when run under the debugger?

Or something else?

Are you using a Nordic board, or something else?

What sensor is it? How is it connected to the board? Are you sure that there is a good ground connection between sensor & board?

RE: ble_app_uart + spi only works with connected J-Link

haakonsh — Fri, 11 Jan 2019 13:02:53 GMT

You need to scope your i/o lines with a digital logic analyzer and compare the two states.