Data Logger (and using cool sensors!)

A lab report by John Q. Student.

In The Report

Include your responses to the bold questions on your own fork of this lab report template. Include snippets of code that explain what you did. Deliverables are due next Tuesday. Post your lab reports as README.md pages on your GitHub, and post a link to that on your main class hub page.

For this lab, we will be experimenting with a variety of sensors, sending the data to the Arduino serial monitor, writing data to the EEPROM of the Arduino, and then playing the data back.

Part A. Writing to the Serial Monitor

a. Based on the readings from the serial monitor, what is the range of the analog values being read?

0-1023

b. How many bits of resolution does the analog to digital converter (ADC) on the Arduino have? 10 bits gives you 0 -1023 discrete values, which is also equal to 5 volts. Every pin has a different capacity for voltage You can also find this on the product page.

to see serial plotter:

! (photo) [Screen Shot 2019-05-10 at 4.17.15 PM.png]

Part B. RGB LED

How might you use this with only the parts in your kit? Show us your solution.

Add resistors.

Part C. Voltage Varying Sensors

1. FSR, Flex Sensor, Photo cell, Softpot

a. What voltage values do you see from your force sensor? 1 volt is analog = 200 the numbers is digital (return value)

code is in this repository...as FSR

b. What kind of relationship does the voltage have as a function of the force applied? (e.g., linear?)

This is linear, while a proximity sensor would not be linear because of the reflection not being read at the same rate.

c. Can you change the LED fading code values so that you get the full range of output voltages from the LED when using your FSR?

You would divide analog by 4, you would get 255

d. What resistance do you need to have in series to get a reasonable range of voltages from each sensor?

My answer: You push really hard and wait to see what is the highest output in the serial monitor. Justin's Answer: It's linear and 0-1023 maps to 0-255

int scaledVoltage = map(voltageValue, 0, 1023, 0, 255);

tried but not true here: look at the threshold for the LED, below voltage threshold, no LED can light, below 1.8 volts (red) , according to the internet. Instead of 5 - 0, we should map it from 1.8 - 5. Different colors have different voltage drop. e. What kind of relationship does the resistance have as a function of stimulus? (e.g., linear?)

2. Accelerometer

a. Include your accelerometer read-out code in your write-up.

3. IR Proximity Sensor

a. Describe the voltage change over the sensing range of the sensor. A sketch of voltage vs. distance would work also. Does it match up with what you expect from the datasheet?

b. Upload your merged code to your lab report repository and link to it here.

Optional. Graphic Display

Take a picture of your screen working insert it here!

Part D. Logging values to the EEPROM and reading them back

1. Reading and writing values to the Arduino EEPROM

a. Does it matter what actions are assigned to which state? Why?

b. Why is the code here all in the setup() functions and not in the loop() functions?

c. How many byte-sized data samples can you store on the Atmega328?

d. How would you get analog data from the Arduino analog pins to be byte-sized? How about analog data from the I2C devices?

e. Alternately, how would we store the data if it were bigger than a byte? (hint: take a look at the EEPROMPut example)

Upload your modified code that takes in analog values from your sensors and prints them back out to the Arduino Serial Monitor.

2. Design your logger

a. Insert here a copy of your final state diagram.

3. Create your data logger!

a. Record and upload a short demo video of your logger in action.