Bumble-B and an ADC with OpenGL make an oscilloscope

Hi all,

During my small semester break I managed to connect my Bumble-b chip to an analog-digital converter (ADC).

With this I can read voltage changes and send the information to the computer to plot live.

Here is a demonstration video:

How its all connected

The Bumble-b is connected to the MCP3204 ADC, here is the schmatic from dflecher’s site:

MCP3204 wiring schematic

Software on the Bumble-B

The pulling is done with a library written by dflecher and help from LUFA (The USB-AVR library). My source is available here I recommend you look at my original Bumble-B post on how to compile and develop.

Software on the computer

To plot I used a pyOpenGL, which is a python binding to draw graphics. I based it off one of the demo examples for pyOpenGL. I did not spend much time on it, and there is a lot to improve. Like adding a grid, more options and speeding up the incoming data. Still, this tiny script is a proof of concept.

Small basic oscilloscope showing a remote control signal

I would be glad if anyone tells me how to speed up the Bumble-b serial communication, and draw faster on PyOpenGL, since this is the current bottleneck for a faster oscilloscope.

Here are all the sources I wrote for this post:

• Source for the bumble-b driver
• Source for the pyOpenGL live plotting scope

Note: This project is also compatible with the upcoming Bumble-b2

That is all for now, I hope to find time to post during this long semester