Most of the required instructions are in the NQC program file listed below.
Spybot Line Follower written in NQC
Steve Hassenplug
http://www.geocities.com/stevehassenplug/
The Spybot should have the light sensor and the red light
pointed towards the line (directly or using the fiber optic cables)
Like this: http://www.brickshelf.com/cgi-bin/gallery.cgi?f=28583
To use:
1) Build Spybot Line follower
2) Download this program to Spybot using BricxCC
( http://hometown.aol.com/johnbinder/bricxcc.htm )
3) Place Spybot on line & press run
4) Move Spybot over line & background
5) Press Touch sensor on Spybot to start it running
The red & green LEDs will show the value read from the light sensor.
The red = 1,2,4 (outside to inside) and the green = 8,16,32 (outside to inside)
This program has 3 ranges.
1) Below min = black = turn right
2) Between min & max = grey = go forward
3) Above max = white = turn left
GreyPercent is the Percent of area defined as between min + max
Increasing this number will speed-up spybot. However it may not follow the line as well.
*/
#define GreyPercent 10
task main()
{
int Min; // low range for moving
int Max; // high range for moving
int tMin; // min light reading
int tMax; // max light reading
SetSensorMode(SENSOR_2,SENSOR_MODE_PERCENT);
SetLight(LIGHT_ON);
tMin = 100;
tMax = 0;
SetDirection(OUT_A+OUT_B,OUT_REV); // change this based on gearing
// SetDirection(OUT_A+OUT_B,OUT_FWD);
// calibrate light sensor
while(SENSOR_1==0) // wait until button is pressed
{
SetLED(LED_MODE_ON,SENSOR_2); // show sensor value on display
if(SENSOR_2<tMin) tMin = SENSOR_2;
if(SENSOR_2>tMax) tMax = SENSOR_2;
}
// set min/max movement values
Min = (tMax-tMin) * (50 - GreyPercent / 2) / 100 + tMin;
Max = (tMax - Min + tMin) ;
while(SENSOR_1==1); // wait until button is released
while(true)
{
SetLED(LED_MODE_ON,SENSOR_2); // show sensor value on display
if (SENSOR_2>=Min)
On(OUT_A);
else
Off(OUT_A);
if (SENSOR_2<=Max)
On(OUT_B);
else
Off(OUT_B);
}
}
