Plotting real time ECG data via serial port

[MatuC]

Ok  thx i'll download the drivers and try again will keep you updated.

Rdgs

Matt

[MatuC]

Hi Joe

After installing the NI-VISA drivers it works. The example you provided is able to plot my data. I would like to know the Y-axis (amplitude) is in which unit. mV?

[Ray.R]

The amplitude was based on a max voltage of 3.3Volts, so the unit would be volts.

You can change it using the maxVolts control on the front panel.

Curious, does the ECG waveform show up properly on the graph?

R

[MatuC]

Hi Joe

It looks more like an amplitude spectrum rather than an actual ECG waveform. It could be due to the raw data from my microcontroller but i'm not sure about that. 

Also as the X-axis progresses in time the width of the graph gets compressed into spikes so I guess thats why it looks more like an amplitude spectrum. Anyway to go abt that?

Rgds

Matt

[Ray.R]

Ah yes...  It is because of the graph type..  Lemme check something.

[Ray.R]

Try this version that uses a Waveform Chart set for sweeps.  You will probably have to "fine tune" the waveform update and history length so that is looks right.

R

[MatuC]

Hi Joe

Thanks again! You've been a great help...i'll try the new version of your example when I get the chance later.

Will post an update then.

[MatuC]

Hi Joe

Sorry for the delayed reply. I'm still getting a similar graph plot and i've tried to tweak some of the settings but to no avail. I'll be trying to implement an external ADC instead of the micocontroller's and test whether the problem lies in the hardware.

But none the less thanks for your help.

Matt

[Ray.R]

If you store what you read from the serial port to file and post the file to this thread, I can have a look at it.

R

[MatuC]

Hi Joe

Does the NI example "basic serial write and read.vi" enable me to view the data from the microcontroller? If it does, I can copy the data within the display window and save it to a txt file and upload it. My ECG device doesn't have a function to output a file with the data. I'll see how I can extract the data and post it when I can.

Rgds

Matt