Autonomous pet feeder that uses ARM Mbed and Raspberry Pi 3. This feeder dispenses 2 different types of pet food for 2 different species of pets and water into a water bowl. Using a Raspberry Pi Camera, the Raspberry Pi runs image recognition using OpenCV to detect when a pet is in front of the feeder. After determining the pet, the Pi sends a signal to the Mbed to dispense the corresponding food and water into the bowls. The Mbed uses sonar and water level sensors to stop dispensing when the bowls are full.
- Arm Mbed LPC1768
- Raspberry Pi 3 Model B+
- Raspberry Pi 3 Camera
- Sonar Sensor (2x)
- Water Pump
- Servo Motor (2x)
- Water Sensor
For the pet detection algorithm, we prioritized speed (frames per second (FPS)) over accuracy so the YOLO architecture was used. Specifically, we used fastest but least accurate variation on the YOLO architecture, the YOLOv3-tiny model. FPS was increased using a technique called quanitzation which converts the neural network weights from float32 type to int8. Most of the code is from this repository, but there were minor changes.
The pet detection algorithm was run on a Raspberry Pi 3 Model B+ with a Raspberry Pi Camera. OpenCV was used to capture images from the camera and feed them through the neural network. This tutorial was used to install OpenCV and to test the interface with the camera.
After following the instructions in the yolo2_light library, Run this command from yolov2_light/bin to start the pet detection algorithm on the Raspberry Pi:
./darknet detector demo coco.names yolov3-tiny.cfg yolov3-tiny.weights -s 10 -thresh 0.1 -quantizedFinal FPS: 0.05 Final mAP: 33.1
#include "mbed.h"
#include "Servo.h"
Servo catServo(p21);
Servo dogServo(p22);
DigitalOut myled(LED1);
DigitalOut myled2(LED2);
PwmOut Ctrl(p25);
RawSerial pi(USBTX, USBRX);
AnalogIn water(p20);
// dog sonar initializations
DigitalOut dogTrigger(p10);
DigitalIn dogEcho(p12);
int dogSonarDistance = 0;
int dogSonarCorrection = 0;
Timer dogSonarTimer;
// cat sonar initializations
DigitalOut catTrigger(p6);
DigitalIn catEcho(p8);
int catSonarDistance = 0;
int catSonarCorrection = 0;
Timer catSonarTimer;
int dist1=0;
int dist2=0;
int dist3=0;
int dist4=0;
int dist5=0;
int dist6=0;
float wat;
bool cond;
bool dogSensed = false;
bool catSensed = false;
bool waterSensed = false;
void fillDogFood() {
printf("dooooooooooog!!!!!!");
// dogTrigger dogSonarTimer to send a ping
dogTrigger = 1;
myled = 1;
myled2 = 0;
dogSonarTimer.reset();
wait_us(10.0);
dogTrigger = 0;
myled = 0;
//wait for dogEcho high
while (dogEcho==0) {};
myled2=dogEcho;
//dogEcho high, so start timer
dogSonarTimer.start();
//wait for dogEcho low
while (dogEcho==1) {};
//stop timer and read value
dogSonarTimer.stop();
//subtract software overhead timer delay and scale to cm
dogSonarDistance = (dogSonarTimer.read_us()-dogSonarCorrection)/58.0;
myled2 = 0;
dist1=dist2;
dist2=dist3;
dist3 = dogSonarDistance;
printf(" %d dog cm \n\r",dogSonarDistance);
if(dist1 >= 50 && dist2>=50 && dist3 >=50){
dogSensed = false;
printf("-------------------------------------------------");
break;
}
if(dogSonarDistance>=0 && dogSonarDistance <=40){
if(dogSonarDistance <= 40 && dogSonarDistance >= 23){
dogServo = 0.3;
wait(0.3);
dogServo = 1.0;
wait(0.7);
}
}
//wait so that any dogEcho(s) return before sending another ping
wait(0.2);
}
void fillCatFood() {
printf("caaaaaaaaaaaaat!!!!!!");
// trigger sonar to send a ping
catTrigger = 1;
catSonarTimer.reset();
wait_us(10.0);
catTrigger = 0;
//wait for echo high
while (catEcho==0) {};
//echo high, so start timer
catSonarTimer.start();
//wait for echo low
while (catEcho==1) {};
//stop timer and read value
catSonarTimer.stop();
//subtract software overhead timer delay and scale to cm
catSonarDistance = (catSonarTimer.read_us()-correction)/58.0;
dist4=dist5;
dist5=dist6;
dist6 = catSonarDistance;
printf(" %d cat cm \n\r",catSonarDistance);
if((dist4 >= 41 && dist5>=41 && dist6 >=41) || (dist4 <= 22 && dist5 <=22 && dist6 <=22)){
printf("-------------------------------------------------");
catSensed = false;
break;
}
if(catSonarDistance>=0 && catSonarDistance <=40){
if(catSonarDistance <= 35 && catSonarDistance >= 23){
catServo = 0.5;
wait(0.3);
catServo = 0.0;
wait(0.7);
}
}
//wait so that any echo(s) return before sending another ping
wait(0.2);
}
void fillWater() {
wat = (float) water;
if(wat >= 0.45){
Ctrl = 0;
waterSensed = false;
} else if(wat<0.20){
Ctrl = 7;
} else{
Ctrl = 0;
waterSensed = false;
}
wait(0.3);
}
void dev_recv()
{
char temp = 0;
myled = !myled;
while(pi.readable()) {
temp = pi.getc();
if (temp=='2') {
myled2 = 1;
catSensed = true;
}
if (temp=='1') {
myled2 = 1;
dogSensed = true;
}
}
}
int main(){
catServo = 0.0;
dogServo = 1.0;
pi.baud(9600);
pi.attach(&dev_recv, Serial::RxIrq);
wait(2);
while(1){
dogSensed = false;
catSensed = false;
// check for signals from Pi
while(!dogSensed && !catSensed) {
sleep();
}
// dog
if (dogSensed) {
// get sonar correction
waterSensed = true;
dogSonarTimer.reset();
dogSonarTimer.start();
while (dogEcho==2) {};
dogSonarTimer.stop();
dogSonarCorrection = dogSonarTimer.read_us();
while (dogSensed || waterSensed) {
if (dogSensed) {
fillDogFood();
}
if (waterSensed) {
fillWater();
}
}
}
// cat food
if (catSensed) {
// get sonar correction
waterSensed = true;
catSonarTimer.reset();
catSonarTimer.start();
while (catEcho==2) {};
catSonarTimer.stop();
catSonarCorrection = catSonarTimer.read_us();
while (catSensed || waterSensed) {
if (catSensed) {
fillCatFood();
}
if (waterSensed) {
fillWater();
}
}
}
wait(10);
myled2 = 0;
}
}