Real Time Data Logging

Patrick Schneider1

Hello everyone,

we wanted to log some data (currents, angle...) in realtime with every control cycle. I tried to accomplish that by using a modified breakpoint for "write data to file".

This approach works quite well beside the fact that CCS is halting the cpu to log the data and therefore the control loop interval is heavily disturbed. In my opinion the C2000 should have the capability to read debug data from memory without halting the cpu.

This seems to be a configuration problem, can one of you hint me to the right configuration parameters or other approaches to solve this problem?

Thanks in advance,

Patrick

over 9 years ago

0 ChrisClearman over 9 years ago

TI__Guru** 119450 points

Patrick,
Why are setting a break point? Why not just write the values to a memory location during the control interrupt?

proj_lab05f has a small example of storing data inside the interrupt for future graphing

0 Patrick Schneider1 over 9 years ago in reply to ChrisClearman

Intellectual 655 points

Thanks for your fast answer Chris.
I already tried that but RAM is limited and unfortunately not sufficient for the test requirements.

0 Jeff Stafford over 9 years ago in reply to Patrick Schneider1

TI__Expert 4595 points

Patrick,

Have you considered using the SPI to send data out every ISR to an external device to collect the data? External device could be another MCU or PC. Companies such as FTDI have products that interface SPI to USB for PC data-logging.

www.ftdichip.com/FTProducts.htm

Jeff

0 Patrick Schneider1 over 9 years ago in reply to Jeff Stafford

Intellectual 655 points

Thanks for your answer Jeff.

I thought about these approaches but they will be obviously more time consuming, thus I tried to realize logging with the IDE (CCS). For my understanding it SHOULD work though, but hence you are pointing in different directions it sounds like its not possible?

Regards,

Patrick

0 Jeff Stafford over 9 years ago in reply to Patrick Schneider1

TI__Expert 4595 points

Hi Patrick,

The whole idea of using a breakpoint, however short the amount of time is, is not a good idea for motor control. Getting real data on your system without causing disturbances in your system is the goal.

Jeff

0 Patrick Schneider1 over 9 years ago in reply to Jeff Stafford

Intellectual 655 points

Hi Jeff,

okay, so is there any way to log data in realtime with Code Composer Studio without disturbing motor control and using external interfaces like sci or spi? Just the debug connection?

Regards,

Patrick

0 Yinghui Zhang over 8 years ago in reply to ChrisClearman

Intellectual 470 points

Hi Chris,

I'm trying to add proj_lab5f data logging feature to lab11a, but I'm a little confuse about how this "Graph_Data" really work.

1. I saw both lab05f, and lab05h has this Graph Data, what's the difference about both implementation ?

2. I just wanted to use either la5f or lab5h as reference to add real-time data logging, which one you'll suggest?

3. what's the logic to implement this graph data feather ? eg. I saw both implementation has sort trigger signal or following some procedure to implement? Could you please help understand it ? In lab5h, there's graph.h, graph.c , I tried include those two files and start from there, but always run into the memory issue. I'm using 28027F processor, how can I solve this issue?

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Real Time Data Logging