Test Harness for Pololu QTR Library
Dependencies: PololuQTRSensors mbed
main.cpp@0:4a43061bfa34, 2015-08-25 (annotated)
- Committer:
- phillippsm
- Date:
- Tue Aug 25 02:50:22 2015 +0000
- Revision:
- 0:4a43061bfa34
- Child:
- 1:f3aee4ff2b19
Alpha Release
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
phillippsm | 0:4a43061bfa34 | 1 | #include "mbed.h" |
phillippsm | 0:4a43061bfa34 | 2 | #include "QTRSensors.h" |
phillippsm | 0:4a43061bfa34 | 3 | #define NUM_SENSORS 7 |
phillippsm | 0:4a43061bfa34 | 4 | Serial pc(USBTX, USBRX); |
phillippsm | 0:4a43061bfa34 | 5 | |
phillippsm | 0:4a43061bfa34 | 6 | DigitalOut myled(LED1); |
phillippsm | 0:4a43061bfa34 | 7 | |
phillippsm | 0:4a43061bfa34 | 8 | // create an object for four QTR-xRC sensors on digital pins 0 and 9, and on analog |
phillippsm | 0:4a43061bfa34 | 9 | // inputs 1 and 3 (which are being used as digital inputs 15 and 17 in this case) |
phillippsm | 0:4a43061bfa34 | 10 | |
phillippsm | 0:4a43061bfa34 | 11 | QTRSensorsAnalog qtra((PinName[]) {A5, A4, A3, A2, A1, A0, PA_3}, NUM_SENSORS, 4, D7); |
phillippsm | 0:4a43061bfa34 | 12 | // PA_3, PA_2, PA_10, PB_3, PB_5, PB_4, PB_10 |
phillippsm | 0:4a43061bfa34 | 13 | |
phillippsm | 0:4a43061bfa34 | 14 | void setup(void); |
phillippsm | 0:4a43061bfa34 | 15 | void readSensors(void); |
phillippsm | 0:4a43061bfa34 | 16 | void readSensorsPlain(void); |
phillippsm | 0:4a43061bfa34 | 17 | |
phillippsm | 0:4a43061bfa34 | 18 | int main() { |
phillippsm | 0:4a43061bfa34 | 19 | pc.printf("Setup!\r\n"); |
phillippsm | 0:4a43061bfa34 | 20 | setup(); |
phillippsm | 0:4a43061bfa34 | 21 | pc.printf("Start Loop!\r\n"); |
phillippsm | 0:4a43061bfa34 | 22 | while(1) { |
phillippsm | 0:4a43061bfa34 | 23 | pc.printf("Read Sensors!\r\n"); |
phillippsm | 0:4a43061bfa34 | 24 | readSensorsPlain(); |
phillippsm | 0:4a43061bfa34 | 25 | } |
phillippsm | 0:4a43061bfa34 | 26 | } |
phillippsm | 0:4a43061bfa34 | 27 | |
phillippsm | 0:4a43061bfa34 | 28 | void setup() |
phillippsm | 0:4a43061bfa34 | 29 | { |
phillippsm | 0:4a43061bfa34 | 30 | // optional: wait for some input from the user, such as a button press |
phillippsm | 0:4a43061bfa34 | 31 | |
phillippsm | 0:4a43061bfa34 | 32 | // then start calibration phase and move the sensors over both |
phillippsm | 0:4a43061bfa34 | 33 | // reflectance extremes they will encounter in your application: |
phillippsm | 0:4a43061bfa34 | 34 | int i; |
phillippsm | 0:4a43061bfa34 | 35 | for (i = 0; i < 50; i++) // make the calibration take about 5 seconds |
phillippsm | 0:4a43061bfa34 | 36 | // originally i < 250 |
phillippsm | 0:4a43061bfa34 | 37 | { |
phillippsm | 0:4a43061bfa34 | 38 | pc.printf("Calibrate Session %d\r\n",i); |
phillippsm | 0:4a43061bfa34 | 39 | qtra.calibrate(QTR_EMITTERS_ON); |
phillippsm | 0:4a43061bfa34 | 40 | wait_ms(20); |
phillippsm | 0:4a43061bfa34 | 41 | } |
phillippsm | 0:4a43061bfa34 | 42 | |
phillippsm | 0:4a43061bfa34 | 43 | for (i = 0; i < NUM_SENSORS; i++) |
phillippsm | 0:4a43061bfa34 | 44 | { |
phillippsm | 0:4a43061bfa34 | 45 | pc.printf("Min On %d \r\n", qtra.calibratedMinimumOn[i]); |
phillippsm | 0:4a43061bfa34 | 46 | } |
phillippsm | 0:4a43061bfa34 | 47 | |
phillippsm | 0:4a43061bfa34 | 48 | // optional: signal that the calibration phase is now over and wait for further |
phillippsm | 0:4a43061bfa34 | 49 | // input from the user, such as a button press |
phillippsm | 0:4a43061bfa34 | 50 | } |
phillippsm | 0:4a43061bfa34 | 51 | |
phillippsm | 0:4a43061bfa34 | 52 | void readSensors() |
phillippsm | 0:4a43061bfa34 | 53 | { |
phillippsm | 0:4a43061bfa34 | 54 | unsigned int sensors[NUM_SENSORS]; |
phillippsm | 0:4a43061bfa34 | 55 | // get calibrated sensor values returned in the sensors array, along with the line position |
phillippsm | 0:4a43061bfa34 | 56 | // position will range from 0 to 2000, with 1000 corresponding to the line over the middle |
phillippsm | 0:4a43061bfa34 | 57 | // sensor. |
phillippsm | 0:4a43061bfa34 | 58 | int position = qtra.readLine(sensors); |
phillippsm | 0:4a43061bfa34 | 59 | |
phillippsm | 0:4a43061bfa34 | 60 | // if all three sensors see very low reflectance, take some appropriate action for this |
phillippsm | 0:4a43061bfa34 | 61 | // situation. |
phillippsm | 0:4a43061bfa34 | 62 | if (sensors[0] > 750 && sensors[1] > 750 && sensors[2] > 750) |
phillippsm | 0:4a43061bfa34 | 63 | { |
phillippsm | 0:4a43061bfa34 | 64 | // do something. Maybe this means we're at the edge of a course or about to fall off |
phillippsm | 0:4a43061bfa34 | 65 | // a table, in which case, we might want to stop moving, back up, and turn around. |
phillippsm | 0:4a43061bfa34 | 66 | pc.printf("do something. Maybe this means we're at the edge of a course or about to fall off a table, in which case, we might want to stop moving, back up, and turn around."); |
phillippsm | 0:4a43061bfa34 | 67 | |
phillippsm | 0:4a43061bfa34 | 68 | //return; |
phillippsm | 0:4a43061bfa34 | 69 | } |
phillippsm | 0:4a43061bfa34 | 70 | |
phillippsm | 0:4a43061bfa34 | 71 | // compute our "error" from the line position. We will make it so that the error is zero |
phillippsm | 0:4a43061bfa34 | 72 | // when the middle sensor is over the line, because this is our goal. Error will range from |
phillippsm | 0:4a43061bfa34 | 73 | // -1000 to +1000. If we have sensor 0 on the left and sensor 2 on the right, a reading of |
phillippsm | 0:4a43061bfa34 | 74 | // -1000 means that we see the line on the left and a reading of +1000 means we see the |
phillippsm | 0:4a43061bfa34 | 75 | // line on the right. |
phillippsm | 0:4a43061bfa34 | 76 | int error = position - 1000; |
phillippsm | 0:4a43061bfa34 | 77 | |
phillippsm | 0:4a43061bfa34 | 78 | int leftMotorSpeed = 200; |
phillippsm | 0:4a43061bfa34 | 79 | int rightMotorSpeed = 200; |
phillippsm | 0:4a43061bfa34 | 80 | if (error < -500) // the line is on the left |
phillippsm | 0:4a43061bfa34 | 81 | leftMotorSpeed = 20; // turn left |
phillippsm | 0:4a43061bfa34 | 82 | if (error > 500) // the line is on the right |
phillippsm | 0:4a43061bfa34 | 83 | rightMotorSpeed = 20; // turn right |
phillippsm | 0:4a43061bfa34 | 84 | |
phillippsm | 0:4a43061bfa34 | 85 | pc.printf("Left Motor %d, Right Motor %d\r\n", leftMotorSpeed, rightMotorSpeed); |
phillippsm | 0:4a43061bfa34 | 86 | myled = 1; // LED is ON |
phillippsm | 0:4a43061bfa34 | 87 | wait_ms(leftMotorSpeed); // 200 ms |
phillippsm | 0:4a43061bfa34 | 88 | myled = 0; // LED is OFF |
phillippsm | 0:4a43061bfa34 | 89 | wait(rightMotorSpeed); // 1 sec |
phillippsm | 0:4a43061bfa34 | 90 | |
phillippsm | 0:4a43061bfa34 | 91 | |
phillippsm | 0:4a43061bfa34 | 92 | // set motor speeds using the two motor speed variables above |
phillippsm | 0:4a43061bfa34 | 93 | } |
phillippsm | 0:4a43061bfa34 | 94 | |
phillippsm | 0:4a43061bfa34 | 95 | |
phillippsm | 0:4a43061bfa34 | 96 | void readSensorsPlain() |
phillippsm | 0:4a43061bfa34 | 97 | { |
phillippsm | 0:4a43061bfa34 | 98 | unsigned int sensors[NUM_SENSORS]; |
phillippsm | 0:4a43061bfa34 | 99 | // get calibrated sensor values returned in the sensors array, along with the line position |
phillippsm | 0:4a43061bfa34 | 100 | // position will range from 0 to 2000, with 1000 corresponding to the line over the middle |
phillippsm | 0:4a43061bfa34 | 101 | // sensor. |
phillippsm | 0:4a43061bfa34 | 102 | pc.printf("before\r\n"); |
phillippsm | 0:4a43061bfa34 | 103 | qtra.readCalibrated(sensors, QTR_EMITTERS_ON); |
phillippsm | 0:4a43061bfa34 | 104 | pc.printf("after\r\n"); |
phillippsm | 0:4a43061bfa34 | 105 | |
phillippsm | 0:4a43061bfa34 | 106 | for (unsigned int i = 0; i < NUM_SENSORS; i++) { |
phillippsm | 0:4a43061bfa34 | 107 | |
phillippsm | 0:4a43061bfa34 | 108 | pc.printf("Sensor Value[%d] %d Min %d Max %d \r\n", i, sensors[i], qtra.calibratedMinimumOn[i], qtra.calibratedMaximumOn[i]); |
phillippsm | 0:4a43061bfa34 | 109 | |
phillippsm | 0:4a43061bfa34 | 110 | } |
phillippsm | 0:4a43061bfa34 | 111 | // set motor speeds using the two motor speed variables above |
phillippsm | 0:4a43061bfa34 | 112 | } |