Project Logs

Collapse

• pimping the board

  davedarko • 09/12/2015 at 15:51 • 4 comments

  I thought about using the Talkie library for arduino with this module, inspired by #Gas Sensor For Emergency Workers , but it is written for 16 MHz and I would have to deal with timers (again). 16MHz resonators are ordered - although I'm not certain that the atmega32L will work properly at 16MHz and 2.8V. I will look into that, but will also order 8MHz resonators as well and maybe a new LDO for 3.3v? I'm also waiting for some 2x3 pin headers for easier programming via an ISP connector and might make a labeled board... idk.

• program progress

  davedarko • 09/04/2015 at 08:50 • 5 comments

  So with the help of the code from #Portable Trollmaster 3000 I was able to set up the module in no time. It works on the atmega32 (no real surprise here). I've made some little changes to the program - I set the sending power all the way up with the help of the datasheet and also worked on the following function. This should make it easier to set the frequency.

  void set_frequency(unsigned long frequency)
  {
    unsigned long factor = frequency / 8192;
    unsigned int upper = (uint8_t) (factor >> 8);
    unsigned int lower = (uint8_t) ((factor << 8) >>8);
    
    Wire.beginTransmission(NS731_I2C_addr);
    Wire.write((uint8_t) 0x0a);     
    Wire.write((uint8_t) lower);    // lower 0XEA is 90.0 Mhz 77 / 33 for 108
    Wire.write((uint8_t) upper);    // upper 0X2A Change those values to change the frequency
    Wire.endTransmission(); 
  }
  

  updated function, removed not needed type castings etc. (thanks to @al1 )

  void set_frequency(unsigned long frequency)
  {
    unsigned long factor = frequency / 8192;
    uint8_t upper = factor >> 8;
    uint8_t lower = factor;
    
    Wire.beginTransmission(NS731_I2C_addr);
    Wire.write((uint8_t) 0x0a);     
    Wire.write(lower);    // lower 0XEA is 90.0 Mhz 77 / 33 for 108
    Wire.write(upper);    // upper 0X2A Change those values to change the frequency
    Wire.endTransmission(); 
  }

• Video

  davedarko • 09/03/2015 at 16:10 • 0 comments

  https://instagram.com/p/7LKkQHsYti/

• Pinout of the module

  davedarko • 09/03/2015 at 12:57 • 0 comments

  There actually is already a good pinout picture, but I wanted to correct the voltage and be on the safe side when it comes to copyrights - so I fired up inkscape.

• sketch for timer

  davedarko • 08/31/2015 at 12:33 • 0 comments

  int output_pin = 15;
  int randNumber;
  
  ISR (TIMER2_COMP_vect)
  {
    PORTD ^= ( 1 << PD7 );
  }
  
  void setup()
  {
    randomSeed(analogRead(0));
    // set LED pin to ouput
    DDRD = ( 1 << PD7 );
  
  //CTC Modus
    TCCR2 = (1 << WGM21);
  
  //Prescaler 64
  //3686400 / 64 / 440 = 131
    TCCR2 |= (1 << CS20);
    TCCR2 |= (1 << CS21);
  //TCCR2 |= (1 << CS22);
  
  //start with an A
    OCR2 = 131 - 1; 
  
  //Enable Compare Interrupt
    TIMSK |= (1<<OCIE2);
  
  //Enable global Interrupts 
    sei();               
  }
  
  void loop()
  {
    randNumber = random(256);
    OCR2 = randNumber;
    delay(250);
  }

  
  

View all 5 project logs