Baudrate serial with Dongle BLE nrf52840

RE: Baudrate serial with Dongle BLE nrf52840

Håkon Alseth — Tue, 25 Apr 2023 14:11:00 GMT

Hi,

Thank you for sharing this.

You are using usb cdc as the backend for your shell implementation, so the transport layer is effectively USB.

[quote user="Piwy"]I subsribe to curstome services witch send accelerometer data, pressure...ect. these data are send at 10HZ for 6 of them and one is send at 50Hz.[/quote]

How many characters are you printing for each of these devices? If you're converting the data to human readable form, the overall throughput over the USB CDC interface will be quite alot more than the bytes you're receiving over BLE.

You have to find where the bottleneck occurs. Receiving data from 7 sensors in total can be problematic wrt. overall BLE throughput.

Q1: How much data (ie. amount of bytes per received payload?) is being sent over BLE for each device?

Q2: Printing the data, ie. converting it from binary to ASCII characters also gives overhead to the USB CDC interface. How much are you printing here?

Kind regards,

Håkon

RE: Baudrate serial with Dongle BLE nrf52840

Piwy — Tue, 25 Apr 2023 12:07:56 GMT

Hi,

Thanks you for your reply.

Here is my zephyr.dts file

devzone.nordicsemi.com/.../7268.zephyr.dts

Kind regards,

Pierre-Yves

RE: Baudrate serial with Dongle BLE nrf52840

Håkon Alseth — Tue, 25 Apr 2023 10:39:53 GMT

Hi,

As the zephyr/tests/bluetooth/shell sample can be configured in many ways, can you please answer these questions so that I'm able to fully understand how you've setup the sample?

[quote user="hkn"]

Which one is it? "uart0" or "cdc_acm_uart0"?

Can you please share your build-folder/zephyr/zephyr.dts file?

[/quote]

Kind regards,

Håkon

RE: Baudrate serial with Dongle BLE nrf52840

Piwy — Mon, 24 Apr 2023 15:09:00 GMT

To have the same confifuration as me you can take the bluettooth shell sample with the dongle BLE nrf52840 dts, i use the exactly same configuration.

Using Bluetooth Shell

With the sample you can scan device and connect to it as a central device in BLE. When youa re conencted you can discover services and subscribe to one caracteristic. I modify the sample to be able to subscribe to more notification. I subsribe to curstome services witch send accelerometer data, pressure...ect. these data are send at 10HZ for 6 of them and one is send at 50Hz.
i try to receive all theses data. When i receive a data i print it with printf or with printk. But the speed of print is more lent than the n umber of data that i receive. I tried to increase the speed of uart0 to be able to print more data but i loss many data, is it possible to print more faster the data that i receive ?

If i receive less data i succed to print them all (it's the working scenario) but i need to print more data.

Is it more clear ?

Kind regards,

Pierre-Yves

RE: Baudrate serial with Dongle BLE nrf52840

Håkon Alseth — Mon, 24 Apr 2023 14:50:13 GMT

[quote user="Piwy"]Are you pointing zephyr,console and zephyr,shell to uart0 or cdc_acm_uart0? => Yes[/quote]

Which one is it? "uart0" or "cdc_acm_uart0"?

Can you please share your build-folder/zephyr/zephyr.dts file?

[quote user="Piwy"]as i say before i have many data that i receive with notification on my shell interface, but when i want to retrieve all the datas, i loss some of them, is it possible to increase the speed of transmission, diplay ?
Maybe i don't explain verywell i'm sorry, told me if it's not clear[/quote]

Could you share an example of a working scenario and a non-working scenario?

Kind regards,

Håkon

RE: Baudrate serial with Dongle BLE nrf52840

Piwy — Fri, 21 Apr 2023 14:22:38 GMT

Are you pointing zephyr,console and zephyr,shell to uart0 or cdc_acm_uart0? => Yes

RE: Baudrate serial with Dongle BLE nrf52840

Piwy — Fri, 21 Apr 2023 14:19:37 GMT

There is also the same overlay in shell-module sample and in all the sample with shell commands

RE: Baudrate serial with Dongle BLE nrf52840

Piwy — Fri, 21 Apr 2023 14:17:54 GMT

yes like i say i use shell bluetooth sample, i use the same configuration as this sample of zephyr

RE: Baudrate serial with Dongle BLE nrf52840

Piwy — Fri, 21 Apr 2023 14:16:31 GMT

as i say before i have many data that i receive with notification on my shell interface, but when i want to retrieve all the datas, i loss some of them, is it possible to increase the speed of transmission, diplay ?
Maybe i don't explain verywell i'm sorry, told me if it's not clear

RE: Baudrate serial with Dongle BLE nrf52840

Håkon Alseth — Fri, 21 Apr 2023 14:15:30 GMT

Can you please share the full overlay file, and your build-folder\zephyr\zephyr.dts file?

Are you pointing zephyr,console and zephyr,shell to uart0 or cdc_acm_uart0?

Kind regards,

Håkon

RE: Baudrate serial with Dongle BLE nrf52840

Piwy — Fri, 21 Apr 2023 14:12:21 GMT

i have this configuration : in my ovverlay:

       
       &zephyr_udc0 {
              cdc_acm_uart0: cdc_acm_uart0 {
                     compatible = "zephyr,cdc-acm-uart";
                     label = "CDC_ACM_0";
              };
       };

And i tried to put uart0 to 1M :

&uart0 {
	compatible = "nordic,nrf-uarte";
	status = "okay";
	current-speed = <1000000>;// <115200>;
	pinctrl-0 = <&uart0_default>;
	pinctrl-1 = <&uart0_sleep>;
	pinctrl-names = "default", "sleep";
};

Here we have the current-speed i spoke about. I'm i correct when i say that this is the monitor speed of the shell command interface ?

RE: Baudrate serial with Dongle BLE nrf52840

Piwy — Fri, 21 Apr 2023 14:09:15 GMT

The baudrate that i spoke about is the monitor baudrate of the shell command interface, as you say i have another device (my pc) that bridges a physical UART interface

It's not really similar because it's not the baudrate monitor, they talk about file transfer, not about the shell interface with NCS

RE: Baudrate serial with Dongle BLE nrf52840

Håkon Alseth — Fri, 21 Apr 2023 13:53:42 GMT

Hi,

In USB CDC ACM, the baud rate is a parameter that can be used if you have another device that bridges a physical UART interface, ie. if you use this as a bridge. Here's a similar explanation:

RE: [nRF52840] USB CDC baud rate

If you use CDC ACM directly with a USB capable device, such as the nRF52840, the communication is indeed USB. You can open the COM port with baud 600, and the communication will still be based on a 12 Mbps PHY.

What speed are you currently seeing?

Kind regards,

Håkon

RE: Baudrate serial with Dongle BLE nrf52840

Piwy — Fri, 21 Apr 2023 13:41:51 GMT

the baud rate that i spoke about is the monitor speed with the shell command

RE: Baudrate serial with Dongle BLE nrf52840

Piwy — Fri, 21 Apr 2023 13:36:28 GMT

I see that you don't unsderstand, USB CDC will jnot ignore the baud rate...

Do you saw what is the sample Bluetooth shell ? or do you know how putty , or minicom work ?

How do you use your dongle BLE with NCS ? Do you use Shell command ?

I use terminos (linux) to control my device and there is a baudrate for the configuration ...

RE: Baudrate serial with Dongle BLE nrf52840

Turbo J — Fri, 21 Apr 2023 13:21:33 GMT

I still don't understand the connection exactly.

Anyways: If you use the USB CDC as "serial port", it will ignore the baud rate setting.

If you use the physical UART, then you need a proper baud rate setting with 1M baud as the max for NRF52840.

RE: Baudrate serial with Dongle BLE nrf52840

Piwy — Fri, 21 Apr 2023 12:04:08 GMT

To talk to your device with a PC you can use generally putty on windows or minicom in linux to be able to use your shell command, and the baudrate is automatically 115200 but i need more faster than 115200

RE: Baudrate serial with Dongle BLE nrf52840

Piwy — Fri, 21 Apr 2023 12:00:20 GMT

I use a linux on my computer and i use sockets to be able to talk to my serial port (dongle BLE nrf52840).

To be able to do the same as PC-BLE-DRIVER but with NCS 2.0, it's necessary to use sockets to receive and transmit data with the device. And to connect in serial port there is a baudrate to configure on sockets side and on the device.

RE: Baudrate serial with Dongle BLE nrf52840

Turbo J — Fri, 21 Apr 2023 10:37:16 GMT

I've read it but I can not really under stand the "socket" part here. Might need more details.

RE: Baudrate serial with Dongle BLE nrf52840

Piwy — Fri, 21 Apr 2023 10:25:44 GMT

But this can't run at 12MBits/s with shell command, this use UART baudrate or there is a configuration needed.

Dongle BLE use only USB : https://www.nordicsemi.com/Products/Development-hardware/nrf52840-dongle

I search solution, please read my ticket before answer ^^

RE: Baudrate serial with Dongle BLE nrf52840

Turbo J — Fri, 21 Apr 2023 09:40:21 GMT

The NRF52840 supports USB, which I stgrongly recommend using as the connection to a PC. This runs at USB full speed (12MBit/s).