Simple POV W/Ardweeny - Persistence of Vision

This is basically a remake of a previous POV project but I scaled it down a bit

The original is from this instructable https://www.instructables.com/id/Arduino-LEDs-fan-POV-APPLAUSE-sign/

This particular one will be given to a relative who has decided she is a Honey Badger . Her inspiration is from a popular YouTube video about Honey Badgers. But the phrase that is produced is easily changed in the code so this is a project that others could use for other reasons.

Supplies

Items used in this project:

At a flea market , I had purchased 5 computer fans for a dollar each so I used one for this project. I was not sure if it would be strong enough to turn with the battery and the attached PCB but it does turn easily.

misc lumber - my basement - 0.00

a length of plastic 9 by 1.25 inches - my basement - 0.00

an Arduino - I use a Ardweeny from SolarBotics - about 10.00

7 red LEDs - already had - 1.00

7 - 470 ohm resistors - 3.00

1 - 7805 voltage regulator - 1.00

1 - 12 volt wall wart - already had - 0.00

2 - small SPST switches - had in my supplies - 0.00

1 - old record - 0.00

also will need : wire, 9v battery , screws, Loctite 5 min epoxy, small PCB from Radio Shack

Begin Assembly

1. Cut a small - 2 by 2 - piece of 1/4 inch plywood and epoxied to the fan hub . Right now the epoxy is the only thing holding the LED assembly to the fan. I have had good luck with the Loctite but it could be the weak link in this setup. Time will tell.

2. I cut a 9 by 1.25 inch piece of plastic from some stock I had. Sheets of plastic can be had at Home Depot. I just guessed at the size and it turned out to be pretty good.

3. Drill 7 holes in one end about 3/8 of an inch apart for the LEDs. I found a drill size that allows the LEDs to be pressed into the holes quite tightly.

4. Insert the 7 LEDs into the holes.

Wiring the Leds and Attaching to the Ardweeny

The Ardweeny from Solarbotics comes in a kit and it requires about 30 minutes to solder the pieces together. It is intended to be used on a breadboard. After I have bread boarded the circuit, I solder it to a small piece of PCB board which I can in turn attach to the plywood . The Ardweeny will spin along with the LEDs.

After the Ardweeny is constructed, it is time to wire up the LEDs. I used a bare copper wire as a common ground wire. Each of the short wires from the LEDs is soldered to the copper wire and then the copper wire is connected to a ground on the Ardweeny. From the longer, positive leg, of the LED attach a wire to the Ardweeny and include a 470 ohm resistor in the circuit.

I connected the LEDs to pins 1,2,3,4,5,6,7 with the inner most LED being connected to pin 1.

A voltage regulator is also needed and I added a small SPST switch so I can control the power to the Ardweeny.

I find using the short lengths of wire with female/male ends already attached in combination with some headers soldered to the PCB will make the build easier and reuse for possible without a lot of desoldering.

After all connections are made, attach the Ardweeny to the plastic with small bolts thru a short length of plastic tubing, which is used as a stand off for the PCB.

Hall Sensor

This time , I did not use a sensor to trigger the LEDs. I was able to get it pretty good in the code.

Finish the Construction

The remaining steps were:

- attach the plastic arm to the wood hub with small wood screws.

- attach the 9 volt battery to the plastic arm . As the battery may need to be replaced, I wire tied it to the arm but that turned out to be not enough of a tie down. As the arm spins , the battery will try to be flung from the arm so I glued in a small piece of wood to keep it from dislodging. Also the more balanced you can get the arm, the less vibration it will do .

- I then built a stand from scrap wood, painted it black

- I attached the fan (which has the arm attached ) to an old LP record . The record inturn is attached to the stand .

- I used a wire tie to make a tension relief for the wire and added a SPST switch so I can turn the power on/off to the fan.

- The AC adapter is a 12volt 200 milli amp that I had around.

The Code

/ Code for the Arduino Bike POV project
The original code is from an internet find which is noted in the comments
I have modified it greatly

Some issues:
without a hall sensor, one will have to play with the time between words to get a reasonably stable image

// Arduino Bike POV
//
// by Scott Mitchell
// www.openobject.org
// Open Source Urbanism
//
// Copyright (C) 2008 Scott Mitchell 12-10-2008
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//

//============================================================
// 6/2011 heavily modified by c. Dubois for my POV project
// Hall sensor is a switch so I used different code for it
// also used a font.h that I found
// ------------------------------------------------------------

// defining the alphabet
#include "font.h"

// define the Arduino LED pins in use
const int LEDpins[] = {
   1,2,3,4,5,6,7};

// number of LEDs
const int charHeight = sizeof(LEDpins);
const int charWidth = 5;
int var = 0;
int worddelay = 50000;

// sensor setup
const int sensorPIN = 0; // define the Arduino sensor pin

// boolean sensorFlag = false; // stores sensor state
int sensVal; // variable to store the value coming from the sensor

const char textString[] = "CLAIRE";
const char textString2[] =" is a ";
const char textString3[] ="HONEY ";
const char textString4[] ="BADGER";

void setup()
{
   pinMode(13, OUTPUT);
    pinMode(1 , OUTPUT);
   pinMode(2, OUTPUT);
    pinMode(3, OUTPUT);
     pinMode(4, OUTPUT);
    pinMode(5, OUTPUT);
    pinMode(6, OUTPUT);
    pinMode(7, OUTPUT);


//   Serial.begin(9600);
}

void loop()
{
   // turn on Led for a circle in middle and proof that arduino is powered
    digitalWrite(13, HIGH);   // set the LED on


// sensVal = analogRead(sensorPIN); // read the Hall Effect Sensor

//    Serial.println(sensVal);
// delay(500 );

// if (sensVal != 1023 ) {

   //   Turn on the leds to test that they work and create circles
digitalWrite(1 , HIGH);   // set the LED on
delay(500);
digitalWrite(2 , HIGH);   // set the LED on
delay(500);
digitalWrite(3 , HIGH);   // set the LED on
delay(500);
digitalWrite(4 , HIGH);   // set the LED on
delay(500);
digitalWrite(5 ,HIGH);   // set the LED on
delay(500);
digitalWrite(6 ,HIGH);   // set the LED on
delay(500);
digitalWrite(7 ,HIGH);   // set the LED on

// delay to let the fan get to speed
     delay (3000);

   // printing every letter of the textString
   // then clear and print textstring2
   var = 0;
while(var < 200){
// do something repetitive 150 times


   for (int k=0; k<sizeof(textString); k++){
     printLetter(textString[k]);
   }

var++;
// space between words
   delayMicroseconds(worddelay);
}

        //clear the LEDs
digitalWrite(1 , LOW);   // set the LED off
digitalWrite(2 , LOW);   // set the LED off
digitalWrite(3 , LOW);   // set the LED off
digitalWrite(4 , LOW);   // set the LED off
digitalWrite(5 ,LOW);   // set the LED off
digitalWrite(6 , LOW);   // set the LED off
digitalWrite(7 , LOW);   // set the LED off

// delay between phrases
     delay (500);



//   ------------------------------
// -- now do second phrase    ----

     var = 0;
     while(var < 100){
// do something repetitive 75 times

      for (int k=0; k<sizeof(textString2); k++){
     printLetter(textString2[k]);
             }

             var++;
              // space between words
   delayMicroseconds(worddelay);
}

       //clear the LEDs
digitalWrite(1 , LOW);   // set the LED off
digitalWrite(2 , LOW);   // set the LED off
digitalWrite(3 , LOW);   // set the LED off
digitalWrite(4 , LOW);   // set the LED off
digitalWrite(5 ,LOW);   // set the LED off
digitalWrite(6 , LOW);   // set the LED off
digitalWrite(7 , LOW);   // set the LED off

// delay between phrases
     delay (500);



// -- now do third phrase    ----

     var = 0;
     while(var < 100){
// do something repetitive 200 times

      for (int k=0; k<sizeof(textString3); k++){
     printLetter(textString3[k]);
             }

             var++;
              // space between words
   delayMicroseconds(worddelay);
}
    //clear the LEDs
digitalWrite(1 , LOW);   // set the LED off
digitalWrite(2 , LOW);   // set the LED off
digitalWrite(3 , LOW);   // set the LED off
digitalWrite(4 , LOW);   // set the LED off
digitalWrite(5 ,LOW);   // set the LED off
digitalWrite(6 , LOW);   // set the LED off
digitalWrite(7 , LOW);   // set the LED off

// delay between phrases
     delay (250);
// -- now do fourth   phrase    ----

     var = 0;
     while(var < 175){
// do something repetitive 200 times

      for (int k=0; k<sizeof(textString4); k++){
     printLetter(textString4[k]);
             }

             var++;
              // space between words
   delayMicroseconds(worddelay);
}
}
// }

// ------------------- Functions _________________

void printLetter(char ch)
{
   // make sure the character is within the alphabet bounds (defined by the font.h file)
   // if it's not, make it a blank character



   if (ch < 32 || ch > 126){
     ch = 32;
   }
   // subtract the space character (converts the ASCII number to the font index number)
   ch -= 32;
   // step through each byte of the character array
   for (int i=0; i<charWidth; i++) {
     byte b = font[ch][i];


     // bit shift through the byte and output it to the pin
     for (int j=0; j<charHeight; j++) {
       digitalWrite(LEDpins[j], !!(b & (1 << j)));

     }
     // space between columns

delayMicroseconds(425);
   }
   //clear the LEDs
digitalWrite(1 , LOW);   // set the LED on
digitalWrite(2 , LOW);   // set the LED on
digitalWrite(3 , LOW);   // set the LED on
digitalWrite(4 , LOW);   // set the LED on
digitalWrite(5 ,LOW);   // set the LED on
digitalWrite(6 , LOW);   // set the LED on
digitalWrite(7 , LOW);   // set the LED on

   // space between letters
   delayMicroseconds(2600);

   }