I'm working on a project where I use a Pi + camera + sensors. I would like to use the picamera module and overlay a moving plot of the real-time sensor readings on the video output by using the picamera.add_overlay(sensor readings)....

Im thinking of using matplotlib to generate a cumulative readings.jpg file every second and then use that as the overlay. Would this method work ?

Stretch goal would be to output to a network stream but am not sure if picamera supports this level of overlay. Ive seen somewhere that it works only for preview - so am a bit confused.



1 Answer 1


I tried different approaches to do this but finally settled on using picamera's add_overlay function to overlay an "image" of a graph of the sensor readings. I believe you can use pygame to develop a more fully functional result but this worked for me.

In a nutshell, I generated saved the output of a matplotlib graph of the sensor readings to the same image file. I then use picamera's add_overlay and update overlay functions to update the image-graph.

I documented how to do this here with a link to code


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