![\"\"](\"http:\/\/dmirpuri.com\/culmination\/wp-content\/uploads\/2016\/05\/orange_codeCode-150x150.png\")
<\/h3>\n<\/h3>\n<\/p>\n
Here I will be explaining the Pixy camera vision sensor along with the PixyMon software, wiring the stepper motor drivers, and coding the Arduino to read the data from the Pixy and map it to run the stepper motors. I used an Arduino UNO, 2 NEMA 17 Stepper Motors, and 2 EasyDrivers by Sparkfun.<\/p>\n
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Pixy is a camera vision sensor and started out as a kickstarter product. More info here.<\/a><\/p>\n <\/p>\n <\/p>\n First I downloaded the Pixymon software, firmware, and Arduino library. If a new firmware is available, the pixy needs to be updated. To update the firmware,<\/p>\n <\/p>\n Next step is teaching the Pixy to track an object. Pixy can learn seven color signatures, numbered 1-7. Color signature 1 is the default signature. To teach Pixy the other signatures (2-7) requires a simple button pressing sequence.<\/p>\n <\/p>\n <\/p>\n Then hooking the Pixy with Arduino is very simple.<\/p>\n <\/p>\n <\/p>\n So for my project, I 3D modeled a ring and printed with a bright orange PLA filament. This is for the user to wear when waving their hand on top of the tank filled with ferrofluid. The Pixy will track this ring because of its color and send information to the Arduino.<\/p>\n <\/p>\n <\/p>\n <\/p>\n Stepper motors\u00a0are perfect for automation or any time you need a motor to turn to a specific point, at a specific speed, in a specific direction.<\/p>\n <\/p>\n The EasyDriver does something called micro stepping. It breaks down that minimum step into smaller micro steps (in this case 8 micro steps per step). Microstepping allows for smoother and more accurate control, but that means that your 200 step stepper, connected to the EasyDriver needs 1600 ( 200 * 8 ) steps to make a full rotation. More info on the EasyDriver here.<\/a><\/p>\n <\/p>\n <\/p>\n Hooking it up with the Arduino (schematic below), I used a 12V 1A power adapter to run both motors.<\/p>\n <\/p>\n <\/p>\n The Arduino code to run the stepper motors is pretty simple.\u00a0It sets up pin 8 and 9 as outputs. It sets them both low to begin with. Then in the main loop, it simply toggles pin 9 high and low, waiting 1ms between toggles. I used pin 9 as the STEP<\/span> control and pin 8 as the DIRECTION<\/span> control to the Easy Driver.<\/p>\n <\/p>\n <\/p>\n Then combining these two (Pixy and stepper motor) required some algorithm. Here is a working code I worked on for this project. I must say that it is not accurate, but it fairly works. You can see some of the videos on the RESULTS<\/a><\/span>\u00a0and TEST<\/a><\/span> page.<\/p>\n I wrote some functions to run the motors in different directions and applied it to the data received from the Pixy.<\/p>\n <\/p>\n #include <SPI.h> \/\/ This is the main Pixy object int dirA = 8; \/\/x-axis int new_posX = pixy.blocks[0].x; \/\/default int new_posY = pixy.blocks[0].y; \/\/default void setup() { pixy.init(); \/\/starts the Pixy void loop() \/\/ grab blocks! if (blocks) \/\/if blocks are detected old_posY = new_posY; if (new_posX != old_posX) { if (change_posX == true || change_posY == true) { void runMotorForw(int _loop, int _dir, int _step) { void runBothMotorForw(int _loop1, int _dir1, int _step1, int _loop2, int _dir2, int _step2) { void runBothMotorBack(int _loop1, int _dir1, int _step1, int _loop2, int _dir2, int _step2) { void stopMotor() { <\/p>\n![\"pixy-cmucam5\"](\"http:\/\/dmirpuri.com\/culmination\/wp-content\/uploads\/2016\/05\/pixy-cmucam5-300x300.png\")
<\/p>\n\n
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![\"PixyCam](\"http:\/\/dmirpuri.com\/culmination\/wp-content\/uploads\/2016\/04\/PixyCam-300x169.jpg\")
<\/p>\n\n
![\"Screen](\"http:\/\/dmirpuri.com\/culmination\/wp-content\/uploads\/2016\/05\/Screen-Shot-2016-05-18-at-3.06.16-AM-300x287.png\")
![\"serial_window\"](\"http:\/\/dmirpuri.com\/culmination\/wp-content\/uploads\/2016\/05\/serial_window-296x300.png\")
<\/p>\n![\"Screen](\"http:\/\/dmirpuri.com\/culmination\/wp-content\/uploads\/2016\/05\/Screen-Shot-2016-05-21-at-8.47.53-PM-275x300.png\")
<\/p>\n<\/h3>\n
Stepper Motor & EasyDriver<\/h3>\n
![\"easydriver\"](\"http:\/\/dmirpuri.com\/culmination\/wp-content\/uploads\/2016\/05\/easydriver-150x150.jpg\")
<\/p>\n![\"2stepperMotorWiring\"](\"http:\/\/dmirpuri.com\/culmination\/wp-content\/uploads\/2016\/05\/2stepperMotorWiring.png\")
<\/p>\n\n
void setup() { \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span><\/h6>\n
\u00a0pinMode(8, OUTPUT); <\/span><\/h6>\n
\u00a0pinMode(9, OUTPUT);<\/span><\/h6>\n
\u00a0digitalWrite(8, LOW);<\/span><\/h6>\n
\u00a0digitalWrite(9, LOW);<\/span><\/h6>\n
}<\/span><\/h6>\n
<\/h6>\n
void loop() {<\/span><\/h6>\n
\u00a0digitalWrite(9, HIGH);<\/span><\/h6>\n
\u00a0delay(1); \u00a0\u00a0\u00a0\u00a0\u00a0<\/span><\/h6>\n
\u00a0digitalWrite(9, LOW);<\/span><\/h6>\n
\u00a0delay(1); \u00a0\u00a0\u00a0\u00a0\u00a0<\/span><\/h6>\n
}<\/span><\/h6>\n<\/blockquote>\n
\n#include <Pixy.h><\/p>\n
\nPixy pixy;<\/p>\n
\nint stepA = 9; \/\/pwm
\nint dirB = 7; \/\/y-axis
\nint stepB = 6; \/\/pwm<\/p>\n
\nint old_posX = new_posX;
\nint cur_posX = 0;
\nint loopX = 0;
\nbool change_posX = false;<\/p>\n
\nint old_posY = new_posY;
\nint cur_posY = 0;
\nint loopY = 0;
\nbool change_posY = false;<\/p>\n
\npinMode(dirA, OUTPUT);
\npinMode(stepA, OUTPUT);
\npinMode(dirB, OUTPUT);
\npinMode(stepB, OUTPUT);
\ndigitalWrite(dirA, LOW);
\ndigitalWrite(stepA, LOW);
\ndigitalWrite(dirB, LOW);
\ndigitalWrite(stepB, LOW);<\/p>\n
\n}<\/p>\n
\n{
\nstatic int i = 0;
\nint j;
\nuint16_t blocks;<\/p>\n
\nblocks = pixy.getBlocks();<\/p>\n
\n{
\ni++;
\nif (i % 1 == 0) \/\/this prints data every frame
\n{
\nfor (j = 0; j < blocks; j++)
\n{
\nold_posX = new_posX;
\nnew_posX = pixy.blocks[0].x;
\ncur_posX = new_posX – old_posX;
\nloopX = abs(cur_posX * 8);<\/p>\n
\nnew_posY = pixy.blocks[0].y;
\ncur_posY = new_posY – old_posY;
\nloopY = abs(cur_posY * 15);<\/p>\n
\nchange_posX = true;
\n}
\nelse if (new_posX == old_posX) {
\nchange_posX = false;
\n}
\nelse if (new_posY != old_posY) {
\nchange_posY = true;
\n}
\nelse if (new_posY == old_posY) {
\nchange_posY = false;
\n}<\/p>\n
\nif (cur_posX > 10 && cur_posY > 3 && new_posX > 0 && new_posX < 160 && new_posY > 0 && new_posY < 100)
\n{
\nrunBothMotorForw(loopX, dirA, stepA, loopY, dirB, stepB); \/\/left down
\nchange_posX = false;
\nchange_posY = false;
\n}
\nelse if (cur_posX < -10 && cur_posY < -3 && new_posX > 160 && new_posX < 300 && new_posY > 100 && new_posY < 200)
\n{
\nrunBothMotorBack(loopX, dirA, stepA, loopY, dirB, stepB); \/\/right up
\nchange_posX = false;
\nchange_posY = false;
\n}
\nelse if (cur_posX > 10 && new_posX > 0 && new_posX < 160 ) {
\nrunMotorForw(loopX, dirA, stepA); \/\/left
\n}
\nelse if (cur_posX < -10 && new_posX > 160 && new_posX < 300) {
\nrunMotorBack(loopX, dirA, stepA); \/\/right
\n}
\nelse if (cur_posY > 3 && new_posY > 0 && new_posY < 100) {
\nrunMotorForw(loopY, dirB, stepB); \/\/down
\n}
\nelse if (cur_posY < -3 && new_posY > 100 && new_posY < 200) {
\nrunMotorBack(loopY, dirB, stepB); \/\/up
\n}
\nelse
\n{
\nchange_posX = false;
\nchange_posY = false;
\nstopMotor();
\n}
\n}
\nelse {
\nstopMotor();
\n}
\n}
\n}
\n}
\nelse {
\nstopMotor();
\n}
\n}<\/p>\n
\nfor (int i = 0; i < _loop; i++) { \/\/200 steps per revolution
\ndigitalWrite(_dir, HIGH);
\ndigitalWrite(_step, HIGH);
\ndelay(1);
\ndigitalWrite(_step, LOW);
\n}
\n}
\nvoid runMotorBack(int _loop, int _dir, int _step) {
\nfor (int i = 0; i < _loop; i++) {
\ndigitalWrite(_dir, LOW);
\ndigitalWrite(_step, HIGH);
\ndelay(1);
\ndigitalWrite(_step, LOW);
\n}
\n}<\/p>\n
\nfor (int i = 0; i < _loop1 && i < _loop2; i++) {
\ndigitalWrite(_dir1, HIGH);
\ndigitalWrite(_dir2, HIGH);
\ndigitalWrite(_step1, HIGH);
\ndigitalWrite(_step2, HIGH);
\ndelay(1);
\ndigitalWrite(_step1, LOW);
\ndigitalWrite(_step2, LOW);
\n}
\n}<\/p>\n
\nfor (int i = 0; i < _loop1 && i < _loop2; i++) {
\ndigitalWrite(_dir1, LOW);
\ndigitalWrite(_dir2, LOW);
\ndigitalWrite(_step1, HIGH);
\ndigitalWrite(_step2, HIGH);
\ndelay(1);
\ndigitalWrite(_step1, LOW);
\ndigitalWrite(_step2, LOW);
\n}
\n}<\/p>\n
\ndigitalWrite(dirA, LOW);
\ndigitalWrite(stepA, LOW);
\ndigitalWrite(dirB, LOW);
\ndigitalWrite(stepB, LOW);
\n}<\/p><\/blockquote>\n\n