What's the shortest interval I can use for ADC, reliably?

ESPHome
1

I’m planning to try an AD8232 with an ESP32. Based on a few tutorials I’ve seen, it seems that the LO - and LO + pins are only used to identify whether the electrode leads are connected. It is the OUTPUT pin that really matters, and this should be connected to an analog pin on the ESP.

I am considering creating a custom component, which would then allow me to use the Shutdown pin when the leads are not connected as shown in this tutorial; however, I am not a coder so I’m tempted just to use ADC with ESPHome for the time being.

If I use ADC with ESPHome, what is the shortest interval I can reliably use so I capture every small detail in the heartbeat?

2

ADC sampling rate: can reach 100000 times per second with Wi-Fi turned off, and 1000 times per second with Wi-Fi turned on.

Analog-to-Digital Converter (ADC) — ESP-FAQ documentation.

1 Like
3

If I guess this, it just a 3 lead ECG. Surely you would be looking to see minimum of 10 seconds or even continuously?

4

Yes, I’d observe the output over some period of time.

5

I would imagine 1000Hz should be enough. From memory it says 100Hz at bottom of most ECGs. If you don’t mind sharing your plan for this? :nerd_face:

6

It does seem that 1000Hz should be sufficient. Apparently 50Hz can even produce somewhat-adequate results, as discussed here.

7

True. Most people couldn’t spot the difference on the paper trace of 40Hz or 100Hz.