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ADC Throttle Voltage Issue

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Reichen Schaller
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ADC Throttle Voltage Issue

I have had an issue with an ADC throttle and after searching through the forum I found some older threads that had people asking very similar questions but never getting them answered. (As far as I could see that is) The issue is that I am using an ADC foot throttle whose range of inputs seems to exceed that of the ~3.3v maximum for adc1. On the throttle itself it says 0.8-4.2v. Additionally, when I measure the range the VESC sets the 100% at about 80% or the throttle's range. Therefore, when I am driving and push the throttle to full (and therefore past where 100% was) the motor cuts off. I can't seem to raise the maximum voltage to account for the throttle's range. Also, I have used this throttle on a previous ESC build and didn't experience any issues. The first 20% of the throttle seems to have no power and the motor instead just makes a humming noise that reminds me of sensorless motors. (This last part is just me, also I am using a 100/250 vesc)

Any insight or help would be welcome!

frank
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You should connect the throttle to3.3V. The pin on the STM processor is not 5V  tolerant! Then you calibrate the throttle, so that full voltage is 100% and minimum voltage is 0%.

There should be a 10K resistor in between ADC1 and GND, close to the port of the VESC controller. If the cable gets damaged, the resistor will pul the signal low ( 0% input).

 

 

Reichen Schaller
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Got it, I have a 10k resister from making the pre-charge circuitry. (Does it matter that the resistor is 10w?) Right now I have the black to ground, the red wire connected to vcc, and the sensor wire to adc1. How do I calibrate the throttle voltage? I don't see any place to change it in the the wizard.

Reichen Schaller

Reichen Schaller
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When you say connect to 3.3v do you mean the little switch hidden inside the 100/250 should be pushed to the 3.3v side?

Reichen Schaller

Reichen Schaller
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Update, so the vesc thinks 100% is 3v while the real 100% is 3.35v. I can't figure out how to make the vesc change 100% to 3.35v. 

Reichen Schaller

Gatze
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You should set the ADC1 End Voltage to 3.3 volts on in the ADC configuration and then mapping tab.