I am using a CTR Talon SRX with a VersaPlanetary integrated encoder and a CIM motor. When I configure the code to use quadrature encoder mode, the Talon remembers the encoder position when the code is disabled, and even while I am flashing new code. That is, if I configure the integrated PID to maintain an angle of zero, and I rotate the motor by hand while the code is being re-flashed, it will spin back to angle of zero, taking into account the rotation that occurred while no code was active.
However, this does not seem to be the case after power cycles. A true absolute encoder would be able to correct for errors built up while the robot is turned off. The Talon SRX seems to reset to zero after power-off. Is this intended, or is there a way to enable a real absolute encoder feature?
The thing you’re looking for is not Quadrature, it’s Pulse Width Position. Quadrature resets every power cycle. Pulse width does not. The only thing, I’d be careful with is the Pulse Width signals are a lot slower than quadrature. What we do is at the beginning of every power cycle, we set the quadrature to equal the Pulse width and then for the rest of the match use quadrature.
This is included in the Versaplanetary Integrated Encoder.
Thank you! That worked perfectly. For everyone’s information, it maintains the exact position as long as the power is on. After a power cycle, it forgets how many rotations have gone by, but remembers where it was within a single revolution.