Re: Checking EBB motor voltage from Inkscape

Home Evil Mad Scientist Forums Egg-Bot Checking EBB motor voltage from Inkscape Re: Checking EBB motor voltage from Inkscape


Hi Brian.

Thanks once more! Using firmware v2.2.3 I am happy to say that the reported motor voltage is no longer varying with different pot meter settings. I am very impressed with your code! I am curious about what was the “bug” in previous versions?
(I am currently participating in the edx – Course; “Embedded systems – Shape the world”, programming a TI Launchpad (ARM chip), see Challenging as I never dipped my toe in the ‘C’ before! )

I had to edit the v_points in my code to get the correct voltage reported. I set the 0 count voltage to 0.0V and the 1023 count voltage to 36.3V ((3.3V/4700Ω)*51700Ω). The measurement is almost spot on with a count value of 333 reporting a voltage of 11.99V. Actual voltage applied is 12.21 which would account for the voltage drop over the diode. With the motors enabled the reported voltage falls to 11.88V due to a slightly larger drop over the diode.

To get “my” code to report correct replace the v_points with this; v_points = [(0,1),(36.3,1023)]
(As the slope is now linear I am re-writing the code, the table interpolate is no longer needed, stay tuned for update.)

A am also curious about the pen arm “failing” code, I have plotted several “hours” of eggs without noticing any problems using version 2.2.1.

Thanks for the explanation on the motor current, will study it closer when time permits.

I am impressed with your coding skills and learn a lot by reading your code!