Blog 22

!BETA!

Hardware used on Arduino:

• DIO | (DIO)
• Jumper cables M-F
• 4 PIN I2C cable F-F
• Analog meter

Programmed with:

• Arduino
• Time Library
• Processing

Connecting the analog meter

Connection between DIO and Arduino:

For this project I had the some what the same connection with my previous 7FETs Stepper Motor projects. I put Jumper cables M-F on A4, A5, VCC and GND. Those cables where connected through a 4 PIN I2C cable with the DIO. The way they are connection is as followed:

DIO PIN	ARDUINO PIN
1(White)	GND
2	A4
3	A5
4(Red)	VCC

Connection between DIO and analog meter

I connected the power and ground from the analog meter with a male-female jumper cable. The Ground from the analog meter is connected with pin 1. The power from the analog meter is connected with pin 3. ( What is the first IO ) The power cable is has two resistors connected on it, because even with low PWM values the pointer already went to it's maximum.

The connector pin layout on the DIO:

2	4	6	8	10
1	3	5	7	9

More information about the pin layout: DIO

Simple Example code

In this code I will show how you can make the Analog meter pointer, be at 50% for ten seconds and being off for 10 seconds. It is just easy code to use to check if the connection works between meter, dio and arduino.

#define DIO 0x42
#include <Wire.h> 

void setup()
{
  Wire.begin(); // wake up I2C bus
  Serial.begin(9600);
  set_var(0x42, 0x30, 0x01);  
  set_var(0x42, 0x5f, 0x01);  
}

byte get_var(byte address, byte reg)
{ 
  byte value;   
  Wire.beginTransmission(address);  
  Wire.write(reg);
  Wire.endTransmission(); 
  delayMicroseconds (10);
  Wire.requestFrom(DIO, 1);
  value = Wire.read();
  return value;
} 

void set_var(byte address, byte reg, byte value)
{
  Wire.beginTransmission(address);      
  delayMicroseconds  (10);
  Wire.write(reg);
  delayMicroseconds  (10);
  Wire.write(value);   
  Wire.endTransmission();    
} 

void loop()
{
  unsigned long DIOAddress; 

  char buf[32];
  set_var(0x42, 0x50, 0x80);  

  DIOAddress = get_var(0x50, 0xb);
  sprintf (buf, "PWM80:  A:%d \r\n", DIOAddress);
  Serial.write (buf); 
 
 delay(10000);
 
  set_var(0x42, 0x50, 0x00);   

  DIOAddress = get_var(0x50, 0xb);
  sprintf (buf, "PWM0 :  A:%d \r\n", DIOAddress);
  Serial.write (buf); 
 
 delay(10000);
 }

DIO Analog Meter - Clock

In this project I made the Arduino version of the clock. What it does is that it read how late it is, and with the time it calculate how much PWM the meter should get to point to the right hour.

The Full script can be found here: Link The file has the name: DIO_CLOCK_ARDUINO2.ino

This script I used for editing is the TimeSerial script( Examples -> Time ), that you get when you download the Time Library. The Time Library is required, when you want to work with time on your Arduino.

Important stuff that is added:

#include <Time.h>  
#define DIO 0x42
#include <Wire.h> 

void setup()  {
Wire.begin();
set_var(0x42, 0x30, 0x01);  
set_var(0x42, 0x5f, 0x01); 
}

unsigned long DIOAddress;
byte CurrentHour = hour();
int HourMax = 11;
int HexMax = 255;
byte Pwm;  
byte NewHour;
 
Serial.print("\r\nCurrent Hour ");
Serial.print(CurrentHour);

if (CurrentHour >= HourMax) {
  NewHour = CurrentHour - 12; 
}   
 
// NewHour = NewHour + 2;
Serial.print("\r\nNew Hour ");
Serial.print(NewHour);

Pwm = NewHour * HexMax / HourMax; 
Serial.print("\r\n Decimal      ");
Serial.print(Pwm, DEC);
Serial.print("\r\n Hexadecimal  ");
Serial.print(Pwm, HEX);
set_var(0x42, 0x50, Pwm); 

DIOAddress = get_var(0x50, 0xb);
Serial.print("\r\n PWM: ");
Serial.print(DIOAddress, HEX);

Useful links

• DIO
• DIO protocol
• Blog 21 - The Raspberry Pi Version of the above projects.
• Guide from oopsohno: How to get the arduino time library up and going
• Blog list