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Jrkg2 feedback method

#1

i am using the jrk2g reading a wheel angle sensor of me tractor which is connected direct to the pololu.

some other farmers have tractors with wheel angle sensors that are connected to the tractors electric system.

is it possible to read out the data from the sensor with a g2 whithout making problem for the tractors electric?

with other controllers we did use ads1115 which are working perfect. (insted of reading with an arduino)

#2

Hello.

It sounds like your sensor is connected to the Jrk G2 as feedback. If that is the case, you can use the “Get variable” command with the “Offset” argument set to the correct value for Feedback to read the feedback value from the Jrk G2. You can find more information about these commands in the “Command reference” and “Variable reference” sections of the Jrk G2 user’s guide respectively.

It is not clear to me what kind of signal your sensor outputs or how you are controlling the Jrk G2. Is there something in particular you think will cause problems with your tractor’s electronics?

Brandon

#3

Hello Brandon! Thank you for your answer. Yesterday I was not quite right in my hurry.

I use the Pololu with the feedback method and a steering angle sensor (Hall sensor) which outputs 0.5 - 4.5 v. I used the analog feedback. i am able to control my 200 ps tractor so well. :slight_smile:

other farmers have tractors with a pre-fitted steering angle sensor. That means the sensor is installed with the tractor electronics. some also use a sensor with 2 outputs which the tractor electronics then compares to safety.

if I read such a sensor with an arduino (I know that from feedback) the tactor will give a disturbance because the arduino has some power for the measurement.
in this case we use an ads1115 which does not make these problems here.

the ads1115 make a differential voltage measurement. That is to say, you will need to make a measurement where neither side of the measurement is at the Arduino ground potential.

my question is: can you tell me how the pololu reads out the analogue values?

#4

We expect the analog inputs on the Jrk G2 to have similar characteristics to the analog pins on an Arduino (including input impedance, which sounds like the main thing you are concerned about). If you found that an external ADC was necessary with the Arduino, it might be difficult to read the sensor directly with the Jrk, but you could give it a try to see how well it works if you haven’t already.

You can find some information about the way the Jrk handles analog voltage feedback under the “Analog feedback on FBA” heading of the “Analog/frequency feedback handling” section of the Jrk G2 user’s guide.

Brandon