Using Scratch

Cat at Fukushima

Rule of the game:

1) Click the green flag to start.

2) Type in the running speed of the cat.

3) Walk through the maze and hit the red rectangle. Beware of the bats! Radiation can penetrate through the wall!

4) The dark-red bat is fatal, the pink bat introduces medium dose of radiation whereas the dark-blue is less harmful.

This application was created using Scratch programming. The source code for this game can be viewed from here.


Stroboscope

What Is Stroboscope?




Components

1 x AA size battery holder (8 batteries)
1 x Arduino Uno
1 x BU111A NPN power transistor
1 x L7605CV voltage regulator
2 x 10kΩ potentiometer
2 x 10μF capacitors
1 x superbright white LED
1 x 220Ω resistor
1 x USB female port
1 x breadboard
Many jumper wires

Instruction Manual can be downloaded here.

Put the components together according to the schematic diagram below.


Get Started


  1. Download and install Arduino software from http://arduino.cc/en/main/software/.

  2. Download LibreOffice from http://www.libreoffice.org/download/libreoffice-fresh/. It also works on Open Office Calc and Microsoft Excel.

  3. Download the user friendly interface here. For LibreOffice or OpenOffice Calc. For Microsoft Excel.

  4. Open the user friendly interface and type the start-up display name under the user input.

  5. Note that the Calibration 1 (Switch) is a switch that measure the execution latency of the LCD code. Calibration 1 (Value) is the output from the Arduino serial monitor when Calibration 1 (Switch) is ON.

    Calibration 2 (Switch) is a switch that measure the execution latency of the entire code. Calibration 2 (Value) is the output from the Arduino serial monitor when Calibration 2 (Switch) is ON.

  6. Calibrate the stroboscope LCD delay.
    1. Change the serial output to ON.
    2. Change the Calibration 1 (Switch) to ON while ensuring that the Calibration 2 (Switch) is OFF.
    3. Copy the Arduino programming or AVR sketch to the Arduino software.
    4. Upload the sketch and click serial monitor.
    5. After clicking the serial monitor, a window appears which output a series of cumulative average related to the LCD code execution delay.
    6. Copy the value to the user friendly interface under the Calibration 1 (Value).

  7. Calibrate the accuracy of the Hz and RPM output.
    1. Change the Calibration 1 (Switch) to OFF and Calibration 2 (Switch) to ON.
    2. If you copy the Arduino programming sketch from step 5c, copy the same programming code to the Arduino software, otherwise use the AVR code if you previously use it to calibrate the LCD delay.
    3. Upload the sketch and click serial monitor.
    4. After clicking the serial monitor, a window appears which output a series of cumulative average related to the delay execution time of the entire code.
    5. Copy the value to the user friendly interface under the Calibration 2 (Value).

  8. Now, we have done with the calibration of the stroboscope. Change the serial output to OFF after calibration to save memory space.

  9. By default, Pin 8 is used as the LED output, therefore type O in the user input. The cells with red texts are pins which are used for the LCD screen and should not be modified at all or else the LCD display will malfunction.

  10. Change Pin A0 and A1 to input. These input come from the potentiometer voltage divider to adjust the frequency of the stroboscope. Note that the potentiometer connected to Pin A1 adjusts the maximum range of the LED blinking frequency while Pin A0 adjusts the exact value of the desired LED blinking frequency.

  11. LED ON Time Delay is 1000 microseconds by default. Changing it will affect the resolution. Increasing the ON time delay increases the brightness of the LED, in return resulting in a lower resolution. There must be a balance between resolution and brightness for the stroboscope to function properly.

  12. The remarks cell output the warning messages or error according to the user input.





Two Types of Sketches

The Arduino Sketch and the AVR + Arduino Sketch both have the same function.

The Arduino Sketch is more user friendly and easier to understand. However, it consume more memory space and has a longer execution time.

The AVR + Arduino Sketch is more efficient. It uses assembly language with a mixture of Arduino programming language to enhance performance, faster execution time and consume lesser memory space.

User can use any sketch according to their own preference.


How to Use?

  1. This section assumes that the users have calibrated and setup the Stroboscope. This instruction will use ceiling fan as an example.

  2. Switch off all the light and switch on the Stroboscope.

  3. Stick a tape on one blade of the ceiling fan.

  4. Turn on the fan and position the LED towards the ceiling fan.

  5. Turn the potentiometer connected to A0 input to maximum and turn the potentiometer connected to A1 input to 10 Hz.

  6. Tune down the potentiometer (A0 input) until the tape AND the fan appears like it has stopped moving.

  7. Look at the LCD display of the stroboscope. The output values (RPM and Hz) are the frequency of the ceiling fan.

  8. The stroboscope has a USB charger. It can charge USB camera, all android and iphones.