Experiment 4: Simple Blink Program

Experiment 4: Blink Program. Open the Arduino website and navigate to the Learning Example and copy and paste the program Blink. Note the /* header comment section*/. Try using a header sections in all your future programs. This example shows the simplest thing you can do with an Arduino to see physical output: it blinks an LED on the board. In the setup section pin 13 is initialized as an output pin. In the loop section pin 13 is turned on high, and the loop delayed there for 1000 milliseconds. The pin 13 is turned off, and kept off and 1000 millisecond. An LED with leads can be added to pins 13 and 14 for more visibility. Modify the program by delaying times and see what happens.

Experiment 3: The Null Program to Board Communication Test

Experiment 3: The Null program tests communication to the board. There are two white LEDs labelled TX and RX, TX for transmit and RX for receive. These two LEDs flicker when the computer is downloading or uploading programs to the Arduino board. On the IDE screen where the Null program was written, there is an button below the Edit menu with a arrow pointing right. When the cursor moves over this button, text appears identifying this as the upload button. A mouse click with the cursor over this upload button will send the program through the USB cable to the Arduino board. Observe the RX and TX light while the null program is uploaded to the board. The flicker of the TX RX LEDs means the board is ready for programing.

Experiment 2: The Null Program

Experiment 2: The Null program interface test. The Null Program is the simplest program that one can do, and is a place to start. The null program above, copied and pasted from Arduino website, contains two basic sections the void setup() section and the void loop() section. The void setup() section is where the code instruction are read and implemented once, like identifying a variable, and the void loop() section is for code that is repeated over and over again. Thirdly there are double forward slashes (//) before comments. These tell the processor to ignore this text and that the text is not an attempt at coding. Clear commenting makes quality programs. 

Getting Started in Programming the Arduino

This is what you need to get started in programming the Arduino: a computer, USB cable, and Arduino board. Laptops make it easy to program while working at the benchtop. First go to the Arduino website (www.arduino.cc) download and install Arduino’s integrated development environment (IDE) software version 1.0.6. We used the Windows version and it worked perfectly on all our Windows OS computers. If your computer does not have internet access, download the software from another computer that has internet access onto a USB drive, and then install the software from the USB drive. It is best if the computer is linked to the internet in order to access the Arduino website and software libraries. The Arduino website has high quality instructions on how to program the Arduino. An Arduino starter kit with USB cable was purchased on Ebay for $22.

Arduino The Documentary (2010) English HD

Project background reference material

Unbalanced Motors on the Smart Car Chassis

Unbalanced motors is one of the first issues to be addressed in the smart  car. Thes 6 V motors are not made equal and pull different currents and rotate at different speeds. The video shows that the left wheel alone pulled 0.16 A, the right wheel alone pulled 0.14 A, both wheel together pulled 0.12 A from the battery pack. The result of this is that the wheels do not turn at the same rate. Moreover, the Arduino chip can only handle 0.04 A of current and would burn out if the motors were driven directly from the Arduino chip.  So, the next task will be to measure the speed of each wheel and control their speeds so that the car will travel in a straight line when wanted. While the motor can be controlled using Arduino programs, a motor shield will have to be used to buffer the  current capacity from 0.040 A to 0.16 A at least. The L293D chip is the remedy for this problem which is a electric buffer between the Arduino and motor that allow you to control voltage, current, and thus the speed of the motors.

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2WD Motor Smart Robot Car Chassis Kit Speed Encoder Battery Box for Arduino 1:48

The HC-SRO4 chip uses ultrasound echolocation to detect objects.

The HC-SR04 uses ultrasound to navigate the robot. The picture show two HC-SR04s, front on the top and back on the bottom. The piezoelectric ceramic transducers transmit (T) and receive (R) ultrasound.

The robot will mimic bats by using echolocation to navigate. Bats use a variety of ultrasonic ranging (echolocation) techniques frequencies beyond 100 kHz, possibly up to 200 kHz. The human can hear sound frequencies from 20 to 20,000 Hz. The HC-SR04 ultrasound device contains piezoelectric ultrasound sensors that emit and resonant to ultrasound at 42 kHz that we cannot hear. 

The backside of the HC-SR04 unit shows three chips, left is an amplifier, center is microcontroller, and right is for serial communication. This project contains a microcontroller to control a microcontroller. This HC-SRO4 is triggered to send out a burst of ultrasound, measure the time it takes the echo to return, and then send the time report to the Arduino as serial communication. The center chip is another microcontroller and its ID is being kept proprietary.

The HC-SRO4s have arrived from china!

AnalogReadSerial

This Arduino and Board are set up to measure voltage at pin A0. Pins A0 to A5 are analog input pins. The red and black wires deliver 5 V from the board across a 12 K variable resistor that is grounded by the black wire going back to GND pin. The blue wire taps the variable resistor that acts like a voltage divider and carries a voltage to pin A0. As the variable resistor is twisted clockwise, the blue wire change voltage from 0 to 5 V.

Copy and Paste public domain program AnalogyRead from the Arduino website into you software window. There is the sketch window where all the programs are written and then downloaded to the microcontroller. To the right is a window the software uses to read information from the chip. In the software, Serial.begins start communication between the computer and the chip. The variable sensorValue is given the value of the voltage at pin A0. The value in memory variable sensorValue is printed on the computer screen to the right. It is a different window opened under the table Tools > Serial Monitor. The delay(1000), every second, allowed the print out to be slow enough for me to do a screen capture of the range from 0 to 5V. As I turned the resistor the values moved from 0 to 1023. 

How long will it really take to get cheap parts from China through Ebay?

The project robot chassis were ordered from Ebay on December 8, 2014 and they arrived today. The DHL tracker information is listed below. Ever wonder how long it will take to get a package from China. It took 9 days for these parts. One of the packages was damaged. I wonder how that will be treated by them. It looks like if you are patient enough to order parts ahead of time, the best prices can be had.

Wednesday, December 17, 2014    Location    Time
16    Delivered - Signed for by : F DOOR                         CINCINNATI    13:47
15    With delivery courier                                                ERLANGER, KY - USA    10:48
14    Arrived at Delivery Facility in ERLANGER - USA    ERLANGER, KY - USA    06:55
13    Departed Facility in CINCINNATI HUB - USA          CINCINNATI HUB, OH - USA    06:17
12    Processed at CINCINNATI HUB - USA                     CINCINNATI HUB, OH - USA    05:50
11    Clearance processing complete at CINCINNATI     CINCINNATI HUB, OH - USA    02:43
10    Arrived at Sort Facility CINCINNATI HUB - USA    CINCINNATI HUB, OH - USA    01:26
Tuesday, December 16, 2014    Location    Time
9    Customs status updated                                            CINCINNATI HUB, OH - USA    10:43
8    Departed Facility in HONG KONG - HONG KONG    HONG KONG - HONG KONG    15:08
7    Clearance processing complete at HONG KONG     HONG KONG - HONG KONG    14:53
6    Processed at HONG KONG - HONG KONG               HONG KONG - HONG KONG    14:53
5    Arrived at Sort Facility HONG KONG -                      HONG KONG - HONG KONG    03:20
Monday, December 15, 2014    Location    Time
4    Customs status updated                                             HONG KONG - HONG KONG    21:17
3    Departed Facility in SINGAPORE - SINGAPORE        SINGAPORE - SINGAPORE    19:27
2    Processed at SINGAPORE - SINGAPORE                   SINGAPORE - SINGAPORE    19:16
Sunday, December 14, 2014    Location    Time
1    Shipment picked up    SINGAPORE -                           SINGAPORE    13:48

I Received Arduino UNO R3 Starter Kit

I spent 2 hours this evening unpacking and assembling my Arduino Starter kit. I opened and mounted to Arduino board and Breadboard. I then went to the Arduino website and installed the Arduino 1.0.6 software. The website has program example and I had fun cutting and pasting an LED blinking program and a Digital Serial State Reading program. You tube also has accompanying videos for each of these experiment. I feel very accomplished for 2 hours of work and encourage to keep practicing the different examples being offered free to memorize the code functions. I like this and think this might have been a good choice for the class. The only power I used was from the USB port.

Arduino $50 Robot Challenge

The challenge was to keep the Arduino Robot Labs fee to $50. I found the following items on Ebay from Asia. I never thought I could do this, and it has not been done yet, but I have hope.

UNO R3 Kit - Starter to Ultimate - Arduino Compatible, LCD, Breadboard, Sensor $21.96

Motor Drive Shield Expansion Board L293D For Arduino $4.48

HC-SR04  Ultrasonic Module Range Distance Measure Transducer Sensor $1.96

2WD Motor Smart Robot Car Chassis Kit Speed Encoder Battery Box for Arduino 1:48 $13.27

Total $41.67 and this is with postage paid. 

Arduino UNO R3 Starter Kit

One thing nice about the Arduino platform is that it was historically developed by educators with open source learning in mind, and there is no heavy corporation control of the patents. I think I might be able to get all the supplies needed to make an Arduino robot for $50 (class fee), but this means ordering the parts directly from China through ebay. For example, Today I ordered the UNO R3 Starter Kit for 21.96! If you don’t mind waiting for slow boat mail, I think these prices are incredible. Everything needed to start coding a microprocessor

Microprocessor Controlled Robot

Almost every piece of electronics we touch is microprocessor controlled. Microprocessors, or microcomputer, are embedded in most of our everyday tools and appliances. One of the most important thing to teach our children is how microprocessors work. We are becoming dependent upon microprocessor controlled devices to the point that our children's quality of life will depend upon their skill and adapting to them. This Super Saturday course on microprocessor controlled robots will introduce the concept of computer programming and the control of a toy robot using student generated programs downloaded in the micro controllers.

One of the most famous commercially available microprocessor controlled robot is call the Boe-Bot sold by Parallax. It uses a microcontroller called the basic stamp that can be programmed in Basic computer language. This robot is high quality and popular, however the cost of $150 takes it too a level where many student cannot afford this toy since many of these toy just sit in the corner of closets after their fun is over. Some student move on to more challenging projects. Not doubt the quality of the Boe-bot is good and there is a lot of online libraries of programs that can be borrowed and tried. 

With the goal of keeping the cost of this course under $50, I have started talking with Rocket Brand Studios about their kit called the Tadpole that is said to sell for $49.95. Maybe with a volume discount and newer low cost  Arduino microprocessor, the goal can be reached.