AME 3623: Project 2

All components of the project are due by Thursday, March 4th at 5pm
Groups are the same as for project 1.
Discussion within groups is fine.
Discussion across groups may not be about the specifics of the solution (general programming/circuit issues are fine to discuss).

For this project, you will be reading analog data from an infrared distance sensor (made by Sharp) and modeling the relationship between the analog values and the distances.

Everyone has been issued one Sharp distance sensor, with a 3-pin cable.

At the end of this project, you should be able to:

connect an analog sensor to your microcontroller,
read analog voltage data, and
display information through a USB serial interface.

Component 0: Library Installation

Create a new project in your Arduino environment.

Download the PeriodicAction.zip library.
Install this library within the Arduino environment:
- Select Sketch menu / Include Library / Add .ZIP Library
- Navigate to and select PeriodicAction.zip
.

You will not need to repeat these steps in the future for this library (although we will install other libraries later later).

Component 1: Microcontroller Circuit

Connect the Sharp infrared distance sensor to your circuit board. In general:

Black/brown is ground
Redish is +5V power
Green/yellow is signal

Wiring:

Connect power and ground from your breadboard. Power for the Sharp sensor must come from Vin of the Teensy (this is the +5V power supply provided by your laptop)
Note: do not connect +5V to +3.3V!
Connect the signal line of the sensor to an analog input pin on the Teensy (analog pins are labeled with "A??", where ?? are digits).
Connect the Analog GND pin on the Teensy to ground.
Note: you will need your LED bar for project 3 - don't disconnect it.

Component 2: Analog Interface Software for Data Collection

Write a data collection program:

Include PeriodicAction.h in your INO file:
```
#include "PeriodicAction.h"
```
Define your analog pin mapping at the top of your INO file:
```
       const int sharpPin = A1;
```
This example corresponds to Arduino analog pin A1.
In setup(), initialize the serial port connected to the USB port, as you did in project 1.
Implement the following function:
```
       void sensor_display_step(){...};       
```
that samples from your distance sensor and prints out its value.
To read from the analog port that we defined above, use the following:
```
       int val = analogRead(sharpPin);
```
This will give you a value in the range 0 ... 1023, corresponding to voltages 0 to 3.3V
To print out the values, use the standard Serial.printf() function:
```
       Serial.printf("Hello, World!\n");
```
See the printf() documentation for more information about formatted printing: printf().

Use the following for your loop function:

       void loop()
       {
          // Call the sensor_display_step() function every 1000 ms
          static PeriodicAction sensor_display_task(1000, sensor_display_step);

          // Check to see if the task is ready to be executed
          sensor_display_task.step();
       }

You can view the output from the Teensy on your computer by clicking on the serial monitor button in the upper-right corner of your Arduino window. Don't forget to set the baud rate to 115200.

Component 3: Data Collection

Set up your sensor so that it is pointed horizontally in a direction that does not have any obstacles. Also, make sure that the sensor is at least 20cm from the surface of the table that you are working on.
Place a flat obstacle at a known distance and record 5 samples of the raw analog value. The obstacle should be orthogonal to the IR beam emitted from the sensor. Record samples at least from the following distances: 8, 9, 10, 14, 20, 30, 40, 60, 80 cm.
Using a tool such as Excel or Matlab, graph the raw value as a function of distance. Also graph the raw value as a function of inverse distance. You will submit these figures; make sure to include a title and axis labels for each.

Hints

You should not have any more calls to delay() in your code, except in setup(). PeriodicAction does what we need here.

What to Hand In

Submit to a zip file to the project2 area on Gradescope by the deadline. This zip file must include:

Documented code. Include both your "ino" file. The documentation requirements are the same as in project 1.
Figures: a copy of the raw and calibrated graphs that you generated (JPG, PNG, PDF or EPS format).

Other components:

Demonstration/Code Review: All group members must be present. This review must be completed within five days of the deadline. However, it is better to complete these reviews as early as possible.

Grading

For this project, we expect:

A properly configured circuit
- Microprocessor installed
- Sharp sensor installed correctly
Properly written software
- Function that reads from the analog port and prints out the integer value
Properly documented code
- Project-level documentation at the top of the ino file: name and group number, date and project number
- Function-level documentation above the function definition. Include an abstract description of what the function does; a list of the names, types and units associated with each parameter and return value; and the effects that the function has on the processor or connected components.
- In-line documentation inside of functions: individual lines or small groups of lines have an English description that describes logically what the code is doing
Labeled figures of:
- Analog sensor value as a function of distance
- Analog sensor value as a function of inverse distance

andrewhfagg -- gmail.com

Last modified: Wed Mar 3 22:34:32 2021