Viewing a snapshot of a voltage wavefom in superchart

Hello everyone,
As part of a home energy monitoring system, I would like to view in graphical form the AC voltage sinewave in my Blynk app. I already have code written in the ESP32 which samples the AC line voltage at a rate of 6 kHz over one 60 Hz cycle, and stores the data in an array. So I end up with 100 samples that I would like to display in a Blynk superchart.
My question is: Is it possible to send a block of 100 samples (integers) to a superchart in one operation? This obviously does not need to be done in real time. I just want to view a snapshot of the waveform every minute or so. Any Ideas? Thanks. Tony

If your running a local server and are willing to adjust the restrictions regarding data frequency then you may be able to get something, but I doubt it will be useable.

With the cloud servers you are limited to around 10 virtual writes per second, before you start to run into server flooding.

I assume that you want to see this in the Live data view?
Data that appears in the other views is averaged over a one minute period before being written to the database.


Superchart only works in real time, data received is time stamped and, as I’ve already said averaged over a one minute period before being written to the database.

This isn’t what Superchart is meant for, so isn’t really the right tool for your task. Unfortunately there aren’t any more appropriate tools available in Blynk.

I guess you could get creative and somehow produce a JPEG and upload this via the image widget, but I can’t think of a simple way of doing this.


Thank you for your response. If I could achieve 5 virtual writes/sec., which sounds possible from what you said, it would take 20 seconds to transfer 100 samples. That’s not bad. But if for some reason this is not acceptable, my plan B was to have the esp32 run a webserver along with the Blynk framework, and independently communicate with a web browser to transfer the data. There is very little information online about whether Blynk and a Wifi webserver can coexist on one ESP32 device. Would you have any insight into this? Again, thank you for your help. Tony

Should be doable. Aslo, with the local server you can write even 100 req/sec.

this is possible as well, but that’s not an easy task.

Thank you. I will experiment and see what I can achieve.