Lab4-Analog Input

Connect Power from Arduino to Breadboard:
A red wire was connected from the 5V power output of the Arduino to the power column of the breadboard. A black wire was connected from the ground input of the Arduino to the breadboard's ground column. Red and black wires were then connected across the breadboard from power and ground columns to the opposite side power and ground columns.

Potentiometer Input:
A potentiometer was connected to the breadboard's power and ground, and the middle pin was connected to the Analog input pin 3 on the Arduino board.


Add an LED for PWM Output:
A wire was connected from the PWM Digital output pin 9 on the Arduino board to a 330 Ohm resistor on the breadboard. The other side of the resistor was connected to an LED, which in turn was connected to ground.


Load a Program to Control the Arduino:
The provided code was loaded on to the Arduino board. The potentiometer was twisted and the values on the serial output fluctuated accordingly. The LED faded brighter and dimmer as the potentiometer resistance was raised and lowered.

Try other Variable Resistors:
A thermistor was connected to the breadboard's power supply, and the other end was connected to a 10K Ohm resistor. The other end of the 10K Ohm resistor was then connected to ground. This was done to create a voltage divider in the circuit. A wire was connected at the junction between the thermistor and 10K Ohm resistor and connected to the Arduino board analog input pin 3. This was done to sense the changes in voltage in the serial output window.

When a 1K Ohm resistor was inserted in place of the 10K Ohm resistor, the serial output reading rose. This is due to the Ohm's Law ratio changing.

Invent Something:
I decided to create an exhibit of how one aspect of vision works. The rod and cone photoreceptor cells on the retina surface respond to darkness and light(& color) respectively. I simulated this by hooking up a photoresistor to the circuit, and splitting the resulting varied voltage across 2 LED's. When a light shone into the photoresistor, the LED representing the cone cell lit up. When the photoresistor received no light, the LED representing the rod cell lit up.

Here's a video demonstration:
http://www.youtube.com/watch?v=oR5DAbMoOi8

Lab3-Electronics

Measuring Voltage:
The Voltage Regulator 7805 was wired to the breadboard. The power jack was then soldered to wiring and connected it to the Voltage Regulator. The voltage through the circuit was tested and proved to be a regulated 5V.


Basic Circuit:
The circuit was rewired to set up a momentary switch, LED, and resistor in series. When the momentary switch was pressed the LED lit up. The multimeter was used to test the required voltage measurements:
+ Voltage across the switch when closed: 0V
+ Voltage across LED: 2V
+ Voltage across resistor: 1.76V



Series:
The momentary switch and resistor were removed from the circuit. Two LEDs were set up in series and they lit up when the power supply was connected to the power jack. The voltage was tested at various points in the circuit:
+ Voltage across each resistor: 2.51 V
+ Voltage across full circuit: 5.03 V
No resistors are needed in this circuit because each LED uses half the voltage and there is no excess voltage to burn out the LED.


Parallel:
The circuit was rewired to set up three resistors in parallel followed by a resistor in series. The voltage across each resistor was 1.92V. The multimeter was placed in series with the circuit and the current reading was 8.36mA.


Varying Voltage:
Three wires were soldered to the potentiometer. The circuit was rewired to set up a resistor and LED in series. The potentiometer was adjusted and the following voltages and LED behavior were observed:
+ Max voltage on potentiometer: 3.61V - Brightest LED
+ High voltage on potentiometer: 2.11V - Less bright LED
+ Low voltage on potentiometer: 1.68V - Dim LED
+ Minimum voltage on potentiometer: 0V - No light LED

Lab2-Digital Input & Output

I went through Chapters 3 & 4 in Getting Started With Arduino. I coded all examples and learned step-by-step what each program was doing.

In particular, I found the idea of adding delays to counter the circuit's refresh rate to be an interesting concept.

I recorded videos for "Blink an LED", "Control an LED with a momentary switch", and "Improve control to make the switch usable".

For "Build a Switch" I decided to use a NERF gun and shoot a bull's-eye. The back side of the bull's-eye had a coiled wire attached. A 2nd layer behind the bull's-eye had a circle of foil attached to another wire. When the NERF bullet hits the target, the impact causes both layers to connect and transmit current. I coded the LED to blink 5 times rapidly and then stop as a sign of success! I recorded a video of the switch in action.

All videos are in reverse chronological order here (click backwards through the videos):
http://robo.to/clintbeharry

Lab1-Soldering

I started by stripping the ends of two wires to allow for a conductive attachment to the switch. I then soldered the two wire ends to the switch. This was a straightforward process but the wire and switch pieces took longer than expected to heat up and melt the solder. I'm looking forward to practicing more soldering!

I completed the Soldering Lab and tested my switch connections. The wires were sturdily attached and the Multimeter reading proved conductance.