Recitation 3

Step 1: Prepare your tilt sensor

 

Task #1: Solder 

 

The first task in this recitation was to solder 2 long cables into a tilt sensor. In this case, the tilt sensor did not have polarity.

 

Task #2: Connect 

We were then asked to wire the following schematic. The schematic was fairly simple, and did not produce major problems.

 

Task #3: Program 

 

For the Initial code, we used the sketch provided in the instructions. This code allowed us to confirm if the sensor was working properly when tilting it.

 

int SENSOR_PIN = 2;    

int tiltVal;

void setup() {

  pinMode(SENSOR_PIN, INPUT);    // Set sensor pin as an INP

  Serial.begin(9600);

}

void loop() {

  // read the state of the sensor

  tiltVal = digitalRead(SENSOR_PIN);

  Serial.println(tiltVal);

  delay(10);

}

Video for Initial code: 

 

 

Step 2: Refine the code

Task #1: Upload

For this task, we uploaded the following code provided to us. This code allowed for the sensor to display 0 or 1 intermittently depending on its position. 

int SENSOR_PIN = 2;int tiltVal;

int prevTiltVal;

void setup() {

  pinMode(SENSOR_PIN, INPUT); // Set sensor pin as an INPUT pin

  Serial.begin(9600);}

void loop() {

  // read the state of the sensor

  tiltVal = digitalRead(SENSOR_PIN);

  // if the tilt sensor value changed, print the new value

  if (tiltVal != prevTiltVal) {

    Serial.println(tiltVal);

  prevTiltVal = tiltVal; 

  } delay(10);

}

 

Video code: 

 

 

 

Step 3 & 4: Wear your sensor and Bicep Curl

This step was very straightforward, I just taped the sensor to my forearm in a way that would allow it to be activated when moving my arm up and down.

 

Video: 

 

 

 

Task 1: add a conditional 

The coding part proved a bit challenging for me. I needed some help from the professors. The code in red is the one for prompts 1 and 2.

1. int SENSOR_PIN = 2;
2. int tiltVal;
3. int prevTiltVal;
4. int curlnumber = 0;
5.  
6. void setup() {
7. pinMode(SENSOR_PIN, INPUT); // Set sensor pin as an INPUT pin
8. Serial.begin(9600);
9. }
10.  
11. void loop() {
12. // read the state of the sensor
13. tiltVal = digitalRead(SENSOR_PIN);
14. // if the tilt sensor value changed, print the new value
15. if (tiltVal != prevTiltVal) {
16.   curlnumber++;
17.   Serial.println(curlnumber);
18.   prevTiltVal = tiltVal;
19.  
20.  
21. }
22. delay(10);
23. }

Video: 

 

Task #2: Count the curls

This task was a bit easier, and the steps were more clear. The red part of the code answers prompts 1, 2 , and 3.

1. int SENSOR_PIN = 2;
2. int tiltVal;
3. int prevTiltVal;
4. int curlnumber = 0;
5.  
6. void setup() {
7. pinMode(SENSOR_PIN, INPUT); // Set sensor pin as an INPUT pin
8. Serial.begin(9600);
9. }
10.  
11. void loop() {
12. // read the state of the sensor
13. tiltVal = digitalRead(SENSOR_PIN);
14. // if the tilt sensor value changed, print the new value
15. if (tiltVal != prevTiltVal) {
16.   curlnumber++;
17.   Serial.println(curlnumber);
18.   prevTiltVal = tiltVal;
19.  
20.  
21. }
22. delay(10);
23. }

Video: 

 

Task #3: Set a limit 

For task 3 I went back to the code and added the part highlighted in red by creating a “if” conditional.

1. int SENSOR_PIN = 2;
2. int tiltVal;
3. int prevTiltVal;
4. int curlnumber = 0;
5.  
6. void setup() {
7. pinMode(SENSOR_PIN, INPUT);  // Set sensor pin as an INPUT pin
8. Serial.begin(9600);
9. }
10.  
11. void loop() {
12. // read the state of the sensor
13. tiltVal = digitalRead(SENSOR_PIN);
14. // if the tilt sensor value changed, print the new value
15. if (tiltVal != prevTiltVal) {
16.   curlnumber++;
17.   Serial.println(curlnumber);
18.   prevTiltVal = tiltVal;
19.   if (curlnumber == 8) {
20.     Serial.println(“Good job”);
21.     curlnumber = 0;
22.   }
23. }
24. delay(10);
25. }

Video: 
 

 

Step 5: Exercise Challenge

For the exercise challenge I figured out that an easy one would be doing jumping jacks, since the arm motion was similar to bicep curls. 

 

Video: 

Documentation:

3. Draw your own illustration sketches that showcase how a person would use this interactive training device.

The sensor would actually keep count of how many repetitions of jumping jacks a person has done.

Reflect on your experiments
 

Reflecting back on this recitation, it appears that the sensor transitions from “HIGH” to “LOW’ at exactly 180 degrees. I also noticed that if you do a short curl its would trigger it faster. If you rotated a limb, the sensor would not trigger because it only reads motion on 2 axis. On the other hand, I noticed that if you shake the sensor, it would cause it to have inaccurate readings, and would make it trigger in quick succession. Also when I grabbed the wires from a few centimeters apart, I noticed it would make the sensor more sensitive. One of the constraints of this sensor is that if a user does not have limbs, it will actually be quite hard for them to use it. Since sticking it to their bodies would prove inconvenient, and would cause inaccurate readings.