SparkFun Forums

[jojojijijojo]

Hi!
I just received my AD8232 board today for a very important project, and when I have setup everything I get a square like wave instead of actual ECG signal. The pads are connected correctly to my chest and lower torso. I power up the board with 3.3v and I double checked that. The LED on the AD8232 is flickering very fast on the same pace as the square waves I see on my output. Please any help is appreciated.

[skimask]

So, what time scale is that?
Months?
Picoseconds?
What?

[jremington]

50/60 Hz noise, I'll bet.
Improper grounding.

[jojojijijojo]

So, what time scale is that?
Months?
Picoseconds?
What?

serial is running at 9600 bauds. I'm graphing the data as soon as they are sent. I tried to have a 1ms wait time, but it gave same result.

[jojojijijojo]

50/60 Hz noise, I'll bet.
Improper grounding.

I'm running using a battery.

[jojojijijojo]

Just to give you more information, the red led on the ecg board is blinking continuously very fast without any input or cable plugged into it. It has an internal noise that keeps genertting spikes on it's own, while running on battery, so no 50/60hz noise problem.
Im starting to believe that the board is defective, and I'm planning a return.

[n1ist]

Unless you are in the middle of nowhere, you can pick up 50/60Hz power line noise. Not from the power supply, from the input.

What is the period of the signal? It's an analog value, so how frequently do you read the ADC? You can use the sample rate and samples between zero crossings to figure out the period. That will tell you if indeed you are picking up line noise.

[MuckS]

Having the same problem-(
Using AD8232 board with Arduino nano (328p mega).

First I had an improper grounding problem. (On processing demo graph it was look like blue and red peaks). When I solved this problem the signal was look like on the picture attached by jojojijijojo. I have no idea how to deal with it. Can you help me? The period of the signal is about 1,5 sec and equal delay.

Here is a screenshot:

(The first part of the demo graph is an improper grounding for example).

[ansg]

In case you're still having this problem, I had it too and found out it comes down to electrode placement, play a bit with your electrode locations, shifting them slightly and eventually you'll get a decent signal. Hope it helps!