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

#21820
ragstian
Participant

Ho.

Ok, here’s a link to a zip file containing the eggbot.py and eggbot.inx.
http://bit.ly/1juocaa
Code will work on EBB hardware v1.3 and above. (The white boards from EMSL are
v2.0, and all boards from SparkFun are v2.0 and above)

Another small change I made a while ago, on reporting the EBB version the com port settings will be listed as well, you will have to make the window larger to see it. Handy to know which com port to use when sending commands directly to the eggbot.

When making a table for the current measurement I discovered the reported motor voltage is dependent on the setting of the current potmeter, my input voltage was 12.22V and the lowest reported motor voltage was 6.97V!
This with the pot meter set fully counter-clockwice for 0 current. (The silkscreen on the board is incorrect! Counter-clockwice rotation will decrease the current.)
Max reported motor voltage was 14.46V at a motor current of 1.04A.
Any idea on why the reported motor voltage is dependent on the current potmeter setting? The two readings (A & V) uses their own AD input on the microcontroller.
I am not sure of the board revision on my eggbot as there are no version info on the board. Board layout date is 10/27/2010. Maybe my board version is too old?
Update: from the schmalhaus web page; “As of hardware version 1.4, the name changed to EiBotBoard”. My board has the “EiBotBoard” printed, board must be at least V1.4.

RGDS
Ragnar