Provide data from .c file to .py file VS Code - matplotlib.pyplot

RE: Provide data from .c file to .py file VS Code - matplotlib.pyplot

Naeem Maroof — Mon, 24 Oct 2022 09:05:58 GMT

Hi Christoph,

I am using a very simple setup to print numbers using printk() function. The main() code is as here:

#include <zephyr.h>
#include <sys/printk.h>


void main(void)
{
	int i=0, res=0;
	while(1)
	{
		res = i * i;
		printk("%d\t%d\n", i, res);
		i++;
		k_msleep(1000);
	}
}

You can use nRF terminal, or any other teriminal like PuTTY (using the correct baudrate configurations). In my case it is 115200.

After you verify you that you can see output in the terminal, then you can disconnect terminal and just run your .py code.

It should fetch lines from COM port and print data accordingly. Please modify as per your needs.

Regards,
Naeem

RE: Provide data from .c file to .py file VS Code - matplotlib.pyplot

ChrtistophAT — Sun, 23 Oct 2022 06:29:56 GMT

Thank you for your help Naeem Maroof !!

Can you provide your main.c code to discover how build up simple serial communication from DK to computer. The nrf terminal and simple terminal are confusig me a bit.

Many thanks!

RE: Provide data from .c file to .py file VS Code - matplotlib.pyplot

Naeem Maroof — Fri, 21 Oct 2022 20:51:50 GMT

Dear Christoph,

Thank you for contacting DevZone at NordicSemi.

As per your query, you are using SAADC example for nRF5340-DK and want to plot the incoming serial data using Python.

The code you have provided is not building and is causing so many errors. Nonetheless, I worked on to solve your basic problem, that is plotting incoming data.

So, I configured my DK to send (x,y) data over UART to the computer. In this case, I am sending square of a number (y = x^2) after every second.

Using online resources, I generated python code which would read from the serial port and then plot in real-time. Please note that the code might not be accurate, and also may not suffice your needs. However, you can use it as guideline and built your own code from it. Other solutions, using commercial data loggers, might also be possible.

So basically,

I am configuring the COM port (in my case its COM5) and the baudrate (as per DK baudrate)
Then, within the animate() function, I am reading a line from the serial port
Then splitting the line data and making a list of items from it
As I know that I am sending (x,y) data, I am expecting 2 items. If there are two items in the list then I extract integer values and put them in x and y list
Then we print the (x,y) data on the plot

Example run of code is shown in the attached image. Python code is also attached. Hope it will be helpful.

devzone.nordicsemi.com/.../main.py

With regards,
Naeem