Config for using sdc_hci_cmd functions

[SJahnke]

Hello,

I'm using a nRF5340 DK and ncs version 2.3.0.

What i try is, to use calls like

•  sdc_hci_cmd_vs_zephyr_read_chip_temp()  that is available in header file sdc_hci_vs.h (ncs/v2.3.0/nrfxlib/softdevice_controller/include) and source file hci_internal.c (\ncs\v2.3.0\nrf\subsys\bluetooth\controller) or
• bt_ctlr_set_public_addr() that uses sd_hci_cmd_vs_zephyr_write_bd_addr() function that is available in the hci_driver.c and the same header file.

I'm always getting the error messages:

• undefined reference to `sdc_hci_cmd_vs_zephyr_read_chip_temp' and
• undefined reference to `bt_ctlr_set_public_addr'

So I'm pretty sure I'm missing a CONFIG in my prj.conf, but can't find the right one. Any Ideas, what i need to add here?

I've started my evaluation with the zephyr beacon sample.

Thanks a lot.

[Susheel Nuguru]

You should not access sdc_hci_cmd_vs_zephyr_read_chip_temp directly from the app, but instead use 

bt_hci_cmd_create-> SDC_HCI_OPCODE_CMD_VS_ZEPHYR_READ_CHIP_TEMP

The function sdc_hci_cmd_vs_zephyr_read_chip_temp  is internal to the controller.

[SJahnke]

Hi Susheel,

thanks for pointing me into that direction. For setting the bluetooth address that work fine for me, like described here: RE: Setting nRF5340 Public BLE Address : So in next step i tried to do the same for the temperature measurement. Inspired by  Error with Bluetooth HCI function: bt_hci_cmd_send_sync I've tried the following to read the temperature:

int temperature_measure(void)
{

	int err = 0;
	struct net_buf *buf, *rsp = NULL;
	sdc_hci_cmd_vs_zephyr_read_chip_temp_return_t *cmd_params;
	sdc_hci_cmd_vs_zephyr_read_chip_temp_return_t *rsp_params;

	buf = bt_hci_cmd_create(SDC_HCI_OPCODE_CMD_VS_ZEPHYR_READ_CHIP_TEMP, sizeof(*cmd_params));
	if (!buf) {
		LOG_ERR("Could not allocate command buffer");
		return -ENOMEM;
	}

	cmd_params = net_buf_add(buf, sizeof(*cmd_params));

	err = bt_hci_cmd_send_sync(SDC_HCI_OPCODE_CMD_VS_ZEPHYR_READ_CHIP_TEMP, buf, &rsp);
	if (err) {
		LOG_ERR("bt_hci_cmd_send_sync failed (err: %d)",err);
		return err;
	}

	rsp_params = (void *) rsp->data;

	net_buf_unref(rsp);

	return 0;
}

But always getting a MPU Fault when using bt_hci_cmd_send_sync():

[00:00:00.253,601] <err> os: ***** MPU FAULT *****
[00:00:00.253,601] <err> os:   Data Access Violation
[00:00:00.253,631] <err> os:   MMFAR Address: 0x5e59
[00:00:00.253,631] <err> os: r0/a1:  0x00000000  r1/a2:  0x00000004  r2/a3:  0x00005e59
[00:00:00.253,662] <err> os: r3/a4:  0x20005418 r12/ip:  0x0000000c r14/lr:  0x00016477
[00:00:00.253,662] <err> os:  xpsr:  0x29000000
[00:00:00.253,662] <err> os: Faulting instruction address (r15/pc): 0x00016bfa
[00:00:00.253,692] <err> os: >>> ZEPHYR FATAL ERROR 0: CPU exception on CPU 0
[00:00:00.253,723] <err> os: Current thread: 0x200015a0 (main)
[00:00:00.938,934] <err> fatal_error: Resetting system

Looks like net_buf_put() forces this.

Any Idea, what's wrong with the code?

Thanks!

Steffen

[Susheel Nuguru]

Hi Steffen, I have another colleague who has seen the same issue with another customer and we are trying to dig a bit into this.

I will be back to you when there are updates, sorry about the delays.

[Hung Bui]

Hi Steffen, 

I'm taking over the case as I have done some more test related to the topic. 

I haven't tested on SDC_HCI_OPCODE_CMD_VS_ZEPHYR_READ_CHIP_TEMP but instead using  BT_HCI_OP_VS_READ_CHIP_TEMP which is similar to how we control TX Power. 
And I can get good result out, I can see temperature around 0x19, 0x1a meaning 25-26 Celsius. 

int temperature_measure(void)
{

	int err = 0;
	struct net_buf *buf, *rsp = NULL;
	struct bt_hci_rp_vs_read_chip_temp *cmd_params;
	struct bt_hci_rp_vs_read_chip_temp *rsp_params;

	buf = bt_hci_cmd_create(BT_HCI_OP_VS_READ_CHIP_TEMP, sizeof(*cmd_params));
	if (!buf) {
		printk("Could not allocate command buffer");
		return -ENOMEM;
	}

	cmd_params = net_buf_add(buf, sizeof(*cmd_params));

	err = bt_hci_cmd_send_sync(BT_HCI_OP_VS_READ_CHIP_TEMP, buf, &rsp);
	if (err) {
		printk("bt_hci_cmd_send_sync failed (err: %d)",err);
		return err;
	}

	rsp_params = (void *) rsp->data;
	printk("result: 0x%x",rsp_params->temps);
	net_buf_unref(rsp);

	return 0;
}

I attached the project here. 

peripheral_lbs_txpower_temp.zip

[SJahnke]

Hi Hung Bui 

thanks for your answer. With BT_HCI_OP_VS_READ_CHIP_TEMP I can also get an result. Thanks a lot.

[frankbuss]

I tried the code and it works. But what unit is it? I get 0x19 as the output, which would be 25 in decimal. Is this degree celsius? The datasheet says accuracy is +/-5°C. Room temperature here is 18°C, so this would be a bit out of range. Or does it need some calibration? And is this calibration then for the given chip long term stable?

When I put the finger on it, the value increases, so it looks like it works. Haven't put it in the freezer so far, what happens with negative temperatures?

[Hung Bui]

Hi Frankbuss, 
It's in Celsius correct. Note that the temperature on the die may not be exactly the same as the room temperature, especially after the chip has been running for awhile. 
You can read more about the accuracy here: 
nRF52840 Internal temperature sensor accuracy

Lowest working temperature is stated in the data specification of the chip, normally the lowest is -40 C.