Solved: Cruise Control: Push to Activate; Cancel on BRK or Throttle Touched

Update 10/25/2023:

3+ years after posting this, I still see people asking about it without a solution in sight, so I bit the bullet and spent a a few hours getting this to work, so I am sure it will be useful for many people that inquired over the years as well.

The problem: Described below in the original post but, in essence, you have to keep the cruise button pressed to keep the cruise mode activated. Keeping the cruise button pressed on a skateboard or even a stand up scooter is ok, and likely safer (it gets released quickly in an emergency), but it get tiring quickly on a larger vehicle. You don't hold the cruise button in your car or a motorcycle to enjoy cruising. A toggle switch would accomplish hands free cruising without the code change but would be a huge downgrade in safety as it requires an action from the driver to disengage.  

How we want it to work:

 Push button is how most cruise control systems work. Push and release to enable and meet some condition to disable, such as touching the brake, pushing the cruise again.

The code below now makes the button attached to PPM/Servo input behave the same way: Get up to speed with throttle and push the button momentarily: cruise is enabled. Push again or touch the brake lever/throttle connected to ADC2 and cruise is disabled. The accelerator can be used to modify RPMs while in cruise mode. The cruise mode will not enable when the motor is not spinning at least with 10% of duty cycle (for safety). Additionally, there is a logic for "longPress" (2 sec) that I wanted to use for reverse. It's not working yet but will be imlemented soon. The same button can be used for legal limiting or anything else. 

Disclaimer: The code was tested on a stand and is expected to work correctly in various situations but use it at your own risk on a vehicle. 

Code:

        // When only one button input is available, use it differently depending on the control mode
            if (config.ctrl_type == ADC_CTRL_TYPE_CURRENT_REV_BUTTON ||
                    config.ctrl_type == ADC_CTRL_TYPE_CURRENT_REV_BUTTON_BRAKE_CENTER ||
                    config.ctrl_type == ADC_CTRL_TYPE_CURRENT_NOREV_BRAKE_BUTTON ||
                    config.ctrl_type == ADC_CTRL_TYPE_DUTY_REV_BUTTON ||
                    config.ctrl_type == ADC_CTRL_TYPE_PID_REV_BUTTON) {
                rev_button = !palReadPad(HW_ICU_GPIO, HW_ICU_PIN);
                if (config.rev_button_inverted) {
                    rev_button = !rev_button;
                }
            } else {

                if ((fabsf(brake_at_cruise - brake)) > 0.1 && cc_button) { // reset cruise if it's active and brake input changed by 0.1v
                    cc_button = false; 
                }

                cc_button_now = !palReadPad(HW_ICU_GPIO, HW_ICU_PIN); // keep the button pin in check
                if (cc_button_now != lastButtonState) { // detect button press

  if (chVTGetSystemTime() - lastTimeButtonStateChanged > longPress) { 
    if (mc_interface_get_duty_cycle_now() < 0.05) { // if not spinning, enable reverse
        lastTimeButtonStateChanged = chVTGetSystemTime();
                  lastButtonState = cc_button_now; // this will set lastButtonstate to the opposite
                          if (cc_button_now == false) {
                              if (rev_button) { //from Cruise On to Off
                                  rev_button = false;
                              }
                  else {
                    cc_button = false; //turning off cruise just in case before enabling reverse
                    rev_button = true;
                  }
  }
    } //end if not spinning (duty cycle is less than 5%
    else {} // if spinning, process something else with a long press, like speed limit setting etc.
  } // end process longPress

    if ((chVTGetSystemTime() - lastTimeButtonStateChanged) > shortPress) { 
        if (mc_interface_get_duty_cycle_now() >= 0.1) { // trigger only if spinning
            lastTimeButtonStateChanged = chVTGetSystemTime(); // need to convert to milliseconds?
                  lastButtonState = cc_button_now; // this will set lastButtonstate to the opposite
                          if (cc_button_now == false) {
                              if (cc_button || rev_button) { //from Cruise On to Off
                                  cc_button = false;
                    rev_button = false; //also disable reverse on short press
                              }
                  else {
                    rev_button = false; //making sure revers is off before enabling cruise
                    cc_button = true;
                    brake_at_cruise = brake; // remember the last set brake input, and check if it changed to disable cruise if it was touched
                  }
  }

    } //end process if spinning

        else {} // do something else on short press and not spinning

  } // end process long press

lastTimeButtonStateChanged = chVTGetSystemTime(); // keep the counter reset if neither short, nor long press is satisfied

} // end detect button press
                
                if (config.cc_button_inverted) {
                    cc_button = !cc_button;
                }

            } //end else

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Original/old post:

I've searched a few topics here about the cruise control but could not find an answer for this specific issue with the CC behavior. I realize VESC has been originally geared towards skateboards and this would make sense for skateboards, but it's a no go on anything with a twist throttle or accelerator pedal.

I tested the servo pin (PB6) to ground and it works, kind of, just not the way cruise control would normally work on a car for example.

It seems like I have to press and hold the cruise button to maintain the speed and it would cancel as soon as I release it. I can make it a switch but it's not safe.

This is how I would set the CC control on my bike with a non-VESC controller: get up to the designed speed, push cruise and release the throttle. The bike maintains the speed regardless of the incline or change in the load, basically keeping the desired RPMs. Touching the throttle, brake input or the cruise button again would immediately cancel cruise. This behavior is very intuitive and safe on a bike. I've used this kind of cruise control on my bikes for years and it has worked very well. Now, any suggestions how we can make it work on ou awesome VESCs?