Setting Up and Using Vision Sensor for Reporting Object Position

Programming Support VEX Coding Studio Tech Support
1

I am trying to write some flag tracking code in VCS. Right now I’m just trying to figure out how to get values for the position of an object in the sensor’s field of view from the vision sensor in real time. Here is my code. What am I doing wrong?

Here is the robot-config.h

vex::brain Brain;
vex::vision::signature RED_FLAGL (1, 8977, 10189, 9583, -1867, -1037, -1452, 3.700000047683716, 0);
vex::vision::signature BLUE_FLAGL (2, -4445, -3827, -4136, 8403, 9909, 9156, 6.400000095367432, 0);
vex::vision::signature SIG_3 (3, 0, 0, 0, 0, 0, 0, 3, 0);
vex::vision::signature SIG_4 (4, 0, 0, 0, 0, 0, 0, 3, 0);
vex::vision::signature SIG_5 (5, 0, 0, 0, 0, 0, 0, 3, 0);
vex::vision::signature SIG_6 (6, 0, 0, 0, 0, 0, 0, 3, 0);
vex::vision::signature SIG_7 (7, 0, 0, 0, 0, 0, 0, 3, 0);
vex::vision flagFinderL (vex::PORT9, 150, RED_FLAGL, BLUE_FLAGL, SIG_3, SIG_4, SIG_5, SIG_6, SIG_7);

Here is the main code:

#include “robot-config.h”

int main() {
while (true){
Brain.Screen.clearScreen(vex::color::black);
flagFinderL.takeSnapshot(RED_FLAGL);
Brain.Screen.setFont(vex::fontType::mono40);
Brain.Screen.setCursor(1,1);
Brain.Screen.print(“%d”, flagFinderL.largestObject.centerY);
Brain.Screen.render();
vex::task::sleep(10);
}
}

2

Considering the complexity of the field light source, vision can not exert its practical ability with our current technology.

3

Wow that is not really a helpful answer for the OP, who was asking an API question.

4

@jpearman

5

Er, yes ??
I don’t see anything particularly wrong. (except there’s really no need to call Brain.Screen.render(), but that’s not relevant to the question).

and also, 150 for brightness seems really high, usually I see values around 50.

6

@jpearman thanks for the response! I had no clue either

7