Paying $50 to whomever can get my digispark to work with I2C & 16x2 LCD

[matt_funder27]

No such luck, if I follow the instructions as described, I get an error that lcd is not declared in this scope
It complies if i use the example within the Adagfruit folder... so not sure whats going on there.

I completely replaced the TinyWireM file, and I already have all of the cores it was wanting me to use.

I added in coding from the other sketches to get it to compile, but that just puts me back at square one.

Code: [Select]

#include <TinyWireM.h>                 // ATtiny I2C communication
//#include <Adafruit_RGBLCDShield.h> // RGB LCD Shield communications
#include <LiquidCrystal_I2C.h> 
//Adafruit_RGBLCDShield lcd = Adafruit_RGBLCDShield();
#define GPIO_ADDR     0x27 
LiquidCrystal_I2C lcd(GPIO_ADDR,16,2);
long secs = 0;

void setup()
{

  lcd.begin(16, 2); // set up the LCD's number of columns and rows.
  lcd.setBacklight(7); // For monochrome LCD lcd.setBacklight(ON)
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Hello World!");
}

void loop()
{
 
}

[wolframore]

You reverted back to #define GPIO_ADDR     0x27

Please try 0x38;

 if (that doesn't work)  0x3F 

[matt_funder27]

I tried both, but I was just able to get a I2C scanner working,


C device found at address 0x3F  !
done

[wolframore]

sweet! does it work now?

[david_prentice]

Go on.   He posted a photo of a PCF8574A with unmounted links on the A0, A1, A2 pins.   i.e. Slave = 0x3F

However,   it is much safer to install Bill Perry's HD44780 library or run an I2C sniffer program.   Then you will know the address.

Or you could just use Codevision C Compiler.  Which supports the I2C backpack.

David.

[matt_funder27]

not yet, I am going bake through all of the previous libraries Ive used to see if any will work using the 0X3F library.

[wolframore]

that's the first address we tried... try David's suggestion on the library.  I can see why I2C is so important on attiny.  what are you making?  Why not just use a 328?

Do we still know if pin 5 and 7 are still good?

[wolframore]

OK try this...


Go here and download:
https://bitbucket.org/fmalpartida/new-liquidcrystal/downloads/

seems not all the libraries work with ATTINY.

Open file I2CIO.cpp

After line 34 insert the code below:

#if defined(__AVR_ATtiny84__) || (__AVR_ATtiny2313__)
#include "TinyWireM.h"      // include this if ATtiny85 or ATtiny2313
#define Wire TinyWireM
#else
#include <Wire.h>           // original lib include
#endif

Code: [Select]



#include <TinyWireM.h>                 // ATtiny I2C communication

#include <LiquidCrystal.I2C.h> 

#define GPIO_ADDR     0x3F 
LiquidCrystal_I2C lcd(GPIO_ADDR, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);
long secs = 0;

void setup()
{

  lcd.begin(16, 2); // set up the LCD's number of columns and rows.
  lcd.setBacklight(ON);
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Hello World!");
}

void loop()
{
 
}



[matt_funder27]

that's the first address we tried... try David's suggestion on the library.  I can see why I2C is so important on attiny.  what are you making?  Why not just use a 328?

Do we still know if pin 5 and 7 are still good?

I want to use a micro controller that is under $3 for my project. Eventually, I would like to just use the Attiny85 alone and not on the digispark. I just Received my Uno, so I can test the screen and I2C.

I will also try your recommendation and reply.

[wolframore]

Good luck... I get 328P chips for $1.50 and make my own.  Attiny isn't a huge savings for the issues it can cause.

[matt_funder27]

Im a man of my word, Wofl please send me a personal message to declare how you would like your payment.

The code below worked for me.

Code: [Select]

/*
 * Interactive nametag sketch for ATtiny85. Based on the Digispark
 * ATtiny LCD example and the Adafruit "Measuring Sound Levels" example.
 * Every 12000 milliseconds will change the display from my name to my website.
 * On the second line, will measure and display sound levels.
 * For more info check: https://platis.solutions/blog/2015/03/22/diy-interactive-name-tag/
 * ATtiny85 I2C pins:
 * ATtiny Pin 5 = SDA on DS1621  & GPIO
 * ATtiny Pin 7 = SCK on DS1621  & GPIO
 */

#include <TinyWireM.h>                  // I2C Master lib for ATTinys which use USI - comment this out to use with standard arduinos
#include <LiquidCrystal_attiny.h>          // for LCD w/ GPIO MODIFIED for the ATtiny85

#define GPIO_ADDR     0x3F
LiquidCrystal_I2C lcd(GPIO_ADDR, 16, 2); // set address & 16 chars / 2 lines

const short micPin = A3;
const short sampleWindow = 50; // Sample window width in mS (50 mS = 20Hz)
const unsigned long nameInterval = 12000;
unsigned long prevNameChange = 0;
short state = 1;
unsigned int sample;

void setup() {
  lcd.init();                           // initialize the lcd
  lcd.backlight();                      // Print a message to the LCD.
  lcd.print("Name: Dimitris");
}

void loop() {
  printName();
  printTemp();
}

void printName() {
  if (millis() - prevNameChange > nameInterval) {
    lcd.setCursor(0, 0);
    if (state) {
      lcd.print("platis.solutions");
    } else {
      lcd.print("Name: Dimitris  ");
    }
    prevNameChange = millis();
    state = !state;
  }
}

void printTemp()
{
  unsigned long startMillis = millis(); // Start of sample window
  unsigned int peakToPeak = 0;   // peak-to-peak level

  unsigned int signalMax = 0;
  unsigned int signalMin = 1024;

  // collect data for 50 mS
  while (millis() - startMillis < sampleWindow)
  {
    sample = analogRead(micPin);
    if (sample < 1024)  // toss out spurious readings
    {
      if (sample > signalMax)
      {
        signalMax = sample;  // save just the max levels
      }
      else if (sample < signalMin)
      {
        signalMin = sample;  // save just the min levels
      }
    }
  }
  peakToPeak = signalMax - signalMin;  // max - min = peak-peak amplitude
  printBars(peakToPeak);
}

void printBars(int bars) {
  if (bars > 14) bars = 14;
  for (int i = 0; i < 15; i++) {
    lcd.setCursor(i, 1);
    if (i <= bars) {
      lcd.print("*");
    } else {
      lcd.print(" ");
    }
  }
}

[Paul__B]

I want to use a micro controller that is under $3 for my project. Eventually, I would like to just use the Attiny85 alone and not on the digispark. I just Received my Uno, so I can test the screen and I2C.

If you want a minimal system, the Pro Mini will cost you less than $2 from China (where else?), is more capable, and you get the PCB with all support parts fitted.  I can't see the point in re-inventing the wheel with bare chips.  

[wolframore]

Matt I just read through your code. That's pretty fun. Is this for s maker faire or a hacker event???