Anyone familiar with Attiny13 programming?

Things said:

Have updated the previous code.

I also changed the pinOptions array to boolean .. though for whatever stupid reason they still occupy 1 byte in Arduino, even though they can only be 0 or 1, 1 bit. The code probably would fit on the tiny13 if that was the case

Click to expand...

rhd said:

My intention for the randomness mode is that it is randomized on powerup. For some context, this build is going to be triggered by a momentary switch (by virtue of a mosfet that controls power to everything, the ATTiny, the buck drivers, etc). So the concept of a random mode is essentially the idea that each "shot" (each triggering of the circuit) would be a different color.

So I'll need to move the random generation into the chip's startup. Does the ATTiny have any kind of temperature sensor, or some sort of input of some sort that we can just hash and get a random number from? Is there anything equivalent to the "randomize timer" function in VB?

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Sigurthr said:

Any suggestions here, Things? You're way more knowledgeable with ATTiny/Arduino than I am.

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Things said:

I'd consider using another EEPROM value as the seed - basically just set the EEPROM value to something random in the main loop, possibly seeded by millis(), then use the EEPROM value as a seed on the next startup (and subsequently re-set it to something else in the loop).

You don't even have to re-randomize on startup, just use the EEPROM value from last time it was randomized

Click to expand...

// RHD's TTL Color Selector
// Programming by Matt "Sigurthr" Giordano 08/13/2014
// www.SigurthrEnterprises.com
// Sigurthr@SigurthrEnterprises.com

// ATTiny85 Physical Pinout - innermost designation is code addressable
//                   _______
// Reset           _|  |_|  |_   Vcc
// ADC3 Pin3   3   _|       |_ 2 Pin2 ADC1
// ADC2 Pin4  A2   _| ATT85 |_ 1 Pin1 Digital-1
// Gnd             _|       |_ 0 Pin0 Digital-0
//                  |_______|
  

#include <EEPROM.h> // include the EEPROM Memory library
boolean pinOptions[7][3] = { // Array of pin combinations (1 = on, 0 = off)
  {1,1,1},
  {1,0,0},
  {1,1,0},
  {0,1,0},
  {0,1,1},
  {0,0,1},
  {1,0,1}
};

byte PressDetects = 0;
byte ButtonPin = 3; // see pinout
byte ColorOnePin = 0; // see pinout
byte ColorTwoPin = 1; // see pinout
byte ColorThreePin = 2; // see pinout
byte MemVar;
byte ButtonPinState;
byte ColorChoice;
byte MemoryLocation = 1;
byte TriggerCount = 10; // threshold for debounce
================================
======start of new stuff========
================================
int RandomVar;
int RandomVarNew;
int GenerateRandom;
===============================
=======end of new stuff========
===============================

void setup (){ // this subroutine runs once upon startup
  MemVar = EEPROM.read(MemoryLocation); // read EEPROM on power on
  pinMode (0, OUTPUT); // set pin 0 to output
  pinMode (1, OUTPUT); // set pin 1 to output
  pinMode (2, OUTPUT); // set pin 2 to output
  pinMode (3, INPUT); // set pin 3 to input

================================
======start of new stuff========
================================
  if (MemVar == 8){
    RandomVar = EEPROM.read(MemoryLocation);
    RandomVar = 9999 * RandomVar
    // does this language allow use of string functions on an int?
    // the following fuction is surely incorrect syntax
    RandomVarNew = int( left(RandomVar, 3) & right(RandomVar, 3) )
    EEPROM.write(RandomVar, RandomVarNew); // Write new number
    ColorChoice = (RandomVarNew % 7) + 1;
  }
===============================
=======end of new stuff========
===============================
}

void loop(){ // this subroutine runs continuously after setup finishes
  ButtonPinState = digitalRead(ButtonPin);  // read ButtonPin to ButtonPinState  
  if (MemVar == 0 || 255){  // first time an EEPROM is read it reads as 255
    MemVar = 1;
  }
  if (ButtonPinState == HIGH){ // when ButtonPinState is HIGH...
    ++ PressDetects; // increment detection variable
  }
  if (PressDetects >= TriggerCount) { // when threshold is exceeded...
    ++ MemVar; // increment memory variable
    PressDetects = 0; // reset button detector
    if (MemVar >= 9){ // on 9th button press...
      MemVar = 1; // reset color
    }  
    if (MemVar == 8){ // on 8th button press...
        ================================
        ======start of new stuff========
        ================================
	GenerateRandom = random(100000, 999999);
	ColorChoice = (GenerateRandom % 7) + 1; // I think this is how you do modulus?
        EEPROM.write(RandomVar, GenerateRandom); // Write initial psuedu random number
        ===============================
        =======end of new stuff========
        ===============================
    }  
    EEPROM.write(MemoryLocation, MemVar); // write color to memory         
  }
  if (MemVar != 8){ // prevents ColorChoice from being set to 8 (invalid)
    ColorChoice = MemVar;
  }  
  digitalWrite(ColorOnePin, pinOptions[ColorChoice-1][0]);
  digitalWrite(ColorTwoPin, pinOptions[ColorChoice-1][1]);
  digitalWrite(ColorThreePin, pinOptions[ColorChoice-1][2]);
}

Sigurthr said:

I think you have to convert the int to binary and then do bitwise math on it in order to select the center bits you want. Likewise the EEPROM can only store a single byte (0-255) of data in a single location, so you'd have to break down the seed into bytes and then store them individually, then recall them and put them back together. That's above my level of expertise unfortunately. My C++ background is CLI level engineering and scientific programs.

Click to expand...

Sigurthr said:

I'm not 100% clear on this next section:

Code:

    RandomVarNew = int( left(RandomVar, 3) & right(RandomVar, 3) )
    EEPROM.write(RandomVar, RandomVarNew); // Write new number
    ColorChoice = (GenerateRandom % 7) + 1;

The first line I assume you're trying to do bitwise math on RandomVar. The second line is clear. The third line I'm not sure of since you didn't initialize the GenerateRandom value prior to this line of code, and thus its value is zero. Zero modulo 7 = 0, +1 = 1. This would set color choice to 1 each time. Was GenerateRandom supposed to be a function and not a variable?

Click to expand...

    RandomVar = EEPROM.read(MemoryLocation);
    RandomVar = 9999 * RandomVar
    RandomVarNew = int( left(RandomVar, 3) & right(RandomVar, 3) )
    EEPROM.write(RandomVar, RandomVarNew); // Write new number
    ColorChoice = (RandomVarNew % 7) + 1;

Sigurthr said:

The more likely solution is probably as Things stated; run a pseudorandom function in the main loop, do a modulo 7 + 1 to get it into range, write it to eeprom, and then use it for a seed. Read eeprom on start up as normal for MemVar, if it is 8 then read the eeprom seed byte and use it in the PRNG to get the new random colorchoice.

Click to expand...

Sigurthr said:

Your edit#1 link doesn't work (the link works, the idea doesn't). I've tried it on regulated and unregulated supplies, the "floating" pins just don't float for me.

I mentioned adding a thermistor and resistor for temperature sensing as a random seed earlier, figured you didn't like it when you didn't mention it since size is an issue. Can easily do that. Just size the resistor to bias the output to ~2.5V at room temp and send that in to the unused ADC line (A2). analogRead it and use as randomSeed, then random(1,7) for ColoChoice. Put all of that in the void setup() inside of an if(){} conditional for MemVar==8.

(I type most of this out for my own reference because tomorrow I will have forgotten the steps to implement otherwise and will have to redo it in my head!)

Click to expand...

Sigurthr said:

Re: Thermistor; you could add amplification via BJTs but you'd be eating up space again.

Will there be any optical splash near the circuit? Or exposed room lighting? Could do a photocell.

Click to expand...