Touch sensor not working

Question

I am attempting to create a very simple program in RobotC. In this program the robot will move forward until the touch sensor is hit.

#pragma config(Sensor, S2,     touchSensor,    sensorTouch)

void setMotors(int a, int b){
    motor[motorA] = a;
    motor[motorB] = b;
}

task main(){
    wait1Msec(100);//Wait for sensor to init

    setMotors(50, 50);

    while(sensorValue(touchSensor) == 0){
        //Do Nothing
    }

    setMotors(0, 0);
}

This code should make the robot move forward until the touch sensor is triggered. Whenever I try and do anything with the touch sensor it does not work. When I output the value to the debug log it shows 180 when pressed and 1024 when released. I have verified that it is working normally by viewing the value on the brick itself.

Robot C Version: 4.0

If what you said is true, you should change the `while` statement to this: `while(sensorValue(touchSensor) == 1024){//Do Nothing }`, right? — Fiddling Bits, Jul 27 '14 at 22:41
@FiddlingBits the problem is the docs say it is either 1 or 0 so thats a problem. — Noah Huppert, Jul 27 '14 at 22:52
@AustinMullins they do not ever spin for more than a milisecond. But the problem when I output to debug log it is either 180 or 1024 nothing in between — Noah Huppert, Jul 27 '14 at 22:53
Awesome, that's what I'd expect given those values. So, change the while statement to `while(sensorValue(touchSensor) > 500)` and let me know what happens. — Austin Mullins, Jul 27 '14 at 22:58
@AustinMullins but why would the documentation say otherwise? — Noah Huppert, Jul 28 '14 at 01:02
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/58135/discussion-between-austin-mullins-and-noah-huppert). — Austin Mullins, Jul 28 '14 at 01:52

score 1 · Accepted Answer · answered Jul 28 '14 at 02:22

Apparently, your touch sensor is stuck in SensorRaw mode. It is unclear - from the documentation I could find - how this could be fixed in code, but a work-around would be to explicitly put the sensor into raw mode (in case the situation changes in the future), and then compute the boolean value with a function like this:

bool sensorIsOn(short sensorRawValue)
{
    bool isOn = false;
    if(sensorRawValue > 512)
    {
        isOn = true;
    }
    return isOn;
}

Touch sensor not working

1 Answers1