launchpad sampling rate issue

[ayemyatzaw17]

We are using a ek-tm4c123gxl tiva c series launchpad that is connected to a sensor that requires
a bit rate of around 600k bits/second output though the bus to get enough data while the uart
baud rate is not able to satisfy this. Is there a way to achieve this rate of data transfer? If
so what communication method would u suggest and how? pls help tq

 

[FvM]

Very unclear. What has sensor bit rate to do with UART rate? What kind of sensor, which interface is it using? Cortex M4 can operate most interfaces with much higher rate than 600 k, even UART.

 

[vishweshgm]

I believe you want to read data from sensor which output values serially at the rate of 600kbps. If this is the case, you should be able to configure your micro to receive serially at this baudrate. Your micro tm4c supports upto 10Mbps.

However to visualize the data on a PC, you will need a software application that lets you configure custom baudrates. If you donot have such application, you may want to read the data using your micro itself by fisrt configuring it to 600k and viewing data in debugger window.

If you want help with configuring clock in your micro, you need to be more specific in the problem statement.

 

[doraemon]

Hello!

Your clock runs at 80 MHz. Don't tell me you can't transmit at 600k. Hint: use DMA when you can.

would u suggest

pls help tq

That's why I will stop here. Why bother if you are not even able to say hello and write full words?

By the way, what / who is tq?

Dora.

 

[ayemyatzaw17]

Very unclear. What has sensor bit rate to do with UART rate? What kind of sensor, which interface is it using? Cortex M4 can operate most interfaces with much higher rate than 600 k, even UART.

hello tq for the response. I want to increase the bit rate sent from the microcontroller to the PC, not the sensor rate. The sensor is merely changing the impedance sent to a pin on the board. And based on the input, the impedance reading on the board is being sent. I tried using UART for the communication but the rate would not go up despite setting a higher baud rate. Any suggestions for me to try out for a higher data rate?

--- Updated Dec 16, 2022 ---

Hello!

Your clock runs at 80 MHz. Don't tell me you can't transmit at 600k. Hint: use DMA when you can.




That's why I will stop here. Why bother if you are not even able to say hello and write full words?

By the way, what / who is tq?

Dora.

Hello Dora! Thank You for the response. (i meant to say thanks by tq) I didnt mean to be very informal or rude for using abbreviations, my bad! I meant to be much more familiar oops. I will try the uDMA function that you suggested after reading the datasheet further. I am Aye by the way and would love more of your expertise on the subject. I will ask you more about DMA after further research. Talk to you soon! -Aye

 

[FvM]

I don't see why PC standard baudrate of 921k shouldn't be possible.

 

[doraemon]

Hello!

I don't see why PC standard baudrate of 921k shouldn't be possible.

It depends on the overhead. You have first start / stop / parity bits which add to the bill.
Then if you have, say, 12 bits data with a 6 bit checksum, etc, UART might be too slow.
Of course it depends on how much data is sent at a time. If it's a low latency system, then
you have to sent all the data separately, which may take its toll on the system.

I was thinking about a DMA system, get an interrupt everytime you get a batch of data
in a buffer, then send the whole also with another DMA, in which case the CPU does
nothing and yes, the UART would make it.

Dora.

 

[FvM]

Useful considerations, but I don't understand the relation to original question which asks for > 600 k bit rate. I don't hear about a processor throughput problem, but may be description is too unclear for me.

 

[danadakk]

Are you trying to reduce the overall time taken for a total process
consisting of sense >> Transfer >> Act/Process/respond ? A block
diagram of problem might be instructive. Whats going on at the
client side of this (PC) ?

We are all confused it seems you have a sensor rate of x but need
to transmit results at y >> x which seems counter intuitive.....

Cortex ARM parts many interfaces including USB FS, SPI to 18 Mbps,
even parallel interface, ethernet.....


Regards, Dana.

 

[doraemon]

Hello!

Useful considerations, but I don't understand the relation to original question which asks for > 600 k bit rate. I don't hear about a processor throughput problem, but may be description is too unclear for me.

Ok, right. But I don't know exactly what experience the original poster has, and beside this what he wants
to achieve is not explained. I wanted to make him aware that 600k of sensor data might yield a significantly
higher bit rate if everything is taken into account.

Dora.