The personal website of Scott W Harden

Solar Powered QRSS Transmitter

Haray! I'm making awesome progress with my QRSS transmitter design. Because my current transmitter (previous few posts) was randomly freezing-up (likely due to the oscillator stopping its oscillating due to being overloaded) so I moved the oscillator from in-chip to an external oscillator. It's been made small enough to fit in an Altoids tin, and I already tested it with the solar panel and it works! Awesome! Here are some photos. Again, when I perfect the design I'll post final schematics.

Sticking out are wires for power and an antenna on each side. The goal is to hang the device between two trees by its own antenna. That's my new chip development board. I made it with what I needed on it. It's so convenient! It uses 5v of power from the USB port too! Altogether I've tested the device and confirmed it transmits radio when the solar panel is illuminated. I'm thinking of making it more effective by adding more panels... but that's it for now!

Markdown source code last modified on January 18th, 2021
---
title: Solar Powered QRSS Transmitter
date: 2010-05-24 07:47:01
tags: qrss
---

# Solar Powered QRSS Transmitter

__Haray!__ I'm making awesome progress with my QRSS transmitter design. Because my current transmitter (previous few posts) was randomly freezing-up (likely due to the oscillator stopping its oscillating due to being overloaded) so I moved the oscillator from in-chip to an external oscillator. It's been made small enough to fit in an Altoids tin, and I already tested it with the solar panel and it works! Awesome! Here are some photos. Again, when I perfect the design I'll post final schematics.

<div class="text-center img-border">

[![](DSCN0532_thumb.jpg)](DSCN0532.jpg)

</div>

<div class="text-center img-border img-small">

[![](DSCN0533_thumb.jpg)](DSCN0533.jpg)
[![](DSCN0535_thumb.jpg)](DSCN0535.jpg)
[![](DSCN0537_thumb.jpg)](DSCN0537.jpg)
[![](DSCN0539_thumb.jpg)](DSCN0539.jpg)

</div>

__Sticking out__ are wires for power and an antenna on each side. The goal is to hang the device between two trees by its own antenna. __That's my new chip development board.__ I made it with what I needed on it. It's so convenient! It uses 5v of power from the USB port too! __Altogether__ I've tested the device and confirmed it transmits radio when the solar panel is illuminated. I'm thinking of making it more effective by adding more panels... but that's it for now!
May 22nd, 2010

First QRSS Spot!

I'm so excited! This little transmitter I made and programmed to transmit my call sign (AJ4VD) and a picture of a gator got its first spotting tonight! I'm so excited. It was reported by W4HBK in Pensacola, FL. It's only 300 miles away, but it's a start! I'm keeping my fingers crossed and maybe someday soon I'll hear from Europe.

Markdown source code last modified on January 18th, 2021
---
title: First QRSS Spot!
date: 2010-05-22 22:47:03
tags: qrss
---

# First QRSS Spot!

__I'm so excited!__ This little transmitter I made and programmed to transmit my call sign (AJ4VD) and a picture of a gator got its first spotting tonight! I'm so excited. It was reported by [W4HBK](http://www.qsl.net/w4hbk/W4HBKgrabber.html) in Pensacola, FL. It's only 300 miles away, but it's a start! I'm keeping my fingers crossed and maybe someday soon I'll hear from Europe.

<div class="text-center img-border">

[![](spotNice_thumb.jpg)](spotNice.jpg)

[![](simple_qrss_transmitter_thumb.jpg)](simple_qrss_transmitter.jpg)

</div>

Debut of the AJ4VD QRSS Gator

I re-wrote the code from the previous entry to do several things. Once of which was to make a gator rather than a fish. It's more appropriate since I'm planning on housing the transmitter at the University of Florida. To do it, I drew a gator in paint and wrote a python script to convert the image into a series of points. I'll post it later. One thing to note was that size was a SERIOUS issue. I only have two thousand bytes of code, and every point of that gator was a byte, so it was a memory hog. I helped it dramatically by using repeating segments wherever possible, and some creative math to help out the best I could (i.e., the spines on the back) Here's what it looks like, and the code below it...

#include <avr/io.h>
#include <util/delay.h>

// front top LED - PA0
// inside top LED - PA1
// inside bot LED - PA2
// front bot LED - PA3

unsigned long int t_unit; // units of time
const int tDit = 100;     //units for a dit
const int tDah = 255;     //units for a dah
char fsk;                 // degree of frequency shift to use for CW
char fsk2;                // degree of frequency shift to use for HELL

char light = 0; // which lights are on/off

void delay()
{
    _delay_loop_2(t_unit);
}

void blink()
{
    return;
    if (light == 0)
    {
        PORTA |= (1 << PA0);  //on
        PORTA |= (1 << PA1);  //on
        PORTA &= ~(1 << PA2); //off
        PORTA &= ~(1 << PA3); //off
        light = 1;
    }
    else
    {
        PORTA |= (1 << PA2);  //on
        PORTA |= (1 << PA3);  //on
        PORTA &= ~(1 << PA0); //off
        PORTA &= ~(1 << PA1); //off
        light = 0;
    }
}

void tick(unsigned long ticks)
{
    while (ticks > 0)
    {
        delay();
        delay();
        ticks--;
    }
}

void pwm_init()
{
    //Output on PA6, OC1A pin (ATTiny44a)
    OCR1A = 0x00;  //enter the pulse width. We will use 0x00 for now, which is 0 power.
    TCCR1A = 0x81; //8-bit, non inverted PWM
    TCCR1B = 1;    //start PWM
}

void set(int freq, int dly)
{
    OCR1A = freq;
    tick(dly);
}

void fish()
{
    char mult = 3;

    char f2[] = {2, 3, 4, 5, 6, 7, 4, 3, 7, 4, 7, 7, 6, 5, 4, 3, 2, 2, 2, 3, 3, 3, 2, 2, 2, 3, 3, 3, 2, 2, 2, 3, 4, 5, 6, 7, 8, 4, 9, 5, 9, 6, 9, 6, 9, 6, 9, 8, 8, 7, 7, 6, 5, 4, 3, 3, 3, 4, 5, 5};

    for (int i = 0; i < sizeof(f2); i++)
    {
        OCR1A = f2[i] * mult;
        blink();
        tick(20);
        OCR1A = 1 * mult;
        blink();
        tick(20);
    }

    char f3[] = {1, 2, 3, 4, 3, 2};

    char offset = 0;
    while (offset < 9)
    {
        for (char j = 0; j < 3; j++)
        {
            for (char i = 0; i < sizeof(f3); i++)
            {
                char val = (f3[i] + 5 - offset) * mult;
                if (val < mult || val > 10 * mult)
                {
                    val = mult;
                }
                OCR1A = val;
                blink();
                tick(20);
                OCR1A = 1 * mult;
                blink();
                tick(20);
            }
        }
        offset++;
    }
}

void id()
{
    char f[] = {0, 0, 1, 2, 0, 1, 2, 2, 2, 0, 1, 1, 1, 1, 2, 0, 1, 1, 1, 2, 0, 2, 1, 1, 0, 0};
    char i = 0;
    while (i < sizeof(f))
    {
        blink();
        if (f[i] == 0)
        {
            OCR1A = 0;
            tick(tDah);
        }
        if (f[i] == 1)
        {
            OCR1A = fsk;
            tick(tDit);
        }
        if (f[i] == 2)
        {
            OCR1A = fsk;
            tick(tDah);
        }
        blink();
        OCR1A = 0;
        tick(tDit);
        i++;
    }
}

void slope()
{
    char i = 0;
    while (i < 25)
    {
        OCR1A = 255 - i;
        i++;
    }
    while (i > 0)
    {
        i--;
        OCR1A = 255 - i;
    }
}

int main(void)
{
    DDRA = 255;
    blink();
    pwm_init();
    t_unit = 1000;
    fsk = 10;
    id(); // set to fast and ID once
          //fsk=50;//t_unit = 65536; // set to slow for QRSS
    t_unit = 60000;

    while (1)
    {
        ;
        fish();
        id();
    }

    return 1;
}
Markdown source code last modified on January 18th, 2021
---
title: Debut of the AJ4VD QRSS Gator
date: 2010-05-22 18:41:54
tags: qrss, old
---

# Debut of the AJ4VD QRSS Gator

__I re-wrote the code__ from the previous entry to do several things. Once of which was to make a gator rather than a fish. It's more appropriate since I'm planning on housing the transmitter at the University of Florida. To do it, I drew a gator in paint and wrote a python script to convert the image into a series of points. I'll post it later. One thing to note was that size was a SERIOUS issue. I only have two thousand bytes of code, and every point of that gator was a byte, so it was a memory hog. I helped it dramatically by using repeating segments wherever possible, and some creative math to help out the best I could (i.e., the spines on the back) Here's what it looks like, and the code below it...

<div class="text-center img-border">

[![](aj4vd_gator_thumb.jpg)](aj4vd_gator.png)

</div>

```c
#include <avr/io.h>
#include <util/delay.h>

// front top LED - PA0
// inside top LED - PA1
// inside bot LED - PA2
// front bot LED - PA3

unsigned long int t_unit; // units of time
const int tDit = 100;     //units for a dit
const int tDah = 255;     //units for a dah
char fsk;                 // degree of frequency shift to use for CW
char fsk2;                // degree of frequency shift to use for HELL

char light = 0; // which lights are on/off

void delay()
{
    _delay_loop_2(t_unit);
}

void blink()
{
    return;
    if (light == 0)
    {
        PORTA |= (1 << PA0);  //on
        PORTA |= (1 << PA1);  //on
        PORTA &= ~(1 << PA2); //off
        PORTA &= ~(1 << PA3); //off
        light = 1;
    }
    else
    {
        PORTA |= (1 << PA2);  //on
        PORTA |= (1 << PA3);  //on
        PORTA &= ~(1 << PA0); //off
        PORTA &= ~(1 << PA1); //off
        light = 0;
    }
}

void tick(unsigned long ticks)
{
    while (ticks > 0)
    {
        delay();
        delay();
        ticks--;
    }
}

void pwm_init()
{
    //Output on PA6, OC1A pin (ATTiny44a)
    OCR1A = 0x00;  //enter the pulse width. We will use 0x00 for now, which is 0 power.
    TCCR1A = 0x81; //8-bit, non inverted PWM
    TCCR1B = 1;    //start PWM
}

void set(int freq, int dly)
{
    OCR1A = freq;
    tick(dly);
}

void fish()
{
    char mult = 3;

    char f2[] = {2, 3, 4, 5, 6, 7, 4, 3, 7, 4, 7, 7, 6, 5, 4, 3, 2, 2, 2, 3, 3, 3, 2, 2, 2, 3, 3, 3, 2, 2, 2, 3, 4, 5, 6, 7, 8, 4, 9, 5, 9, 6, 9, 6, 9, 6, 9, 8, 8, 7, 7, 6, 5, 4, 3, 3, 3, 4, 5, 5};

    for (int i = 0; i < sizeof(f2); i++)
    {
        OCR1A = f2[i] * mult;
        blink();
        tick(20);
        OCR1A = 1 * mult;
        blink();
        tick(20);
    }

    char f3[] = {1, 2, 3, 4, 3, 2};

    char offset = 0;
    while (offset < 9)
    {
        for (char j = 0; j < 3; j++)
        {
            for (char i = 0; i < sizeof(f3); i++)
            {
                char val = (f3[i] + 5 - offset) * mult;
                if (val < mult || val > 10 * mult)
                {
                    val = mult;
                }
                OCR1A = val;
                blink();
                tick(20);
                OCR1A = 1 * mult;
                blink();
                tick(20);
            }
        }
        offset++;
    }
}

void id()
{
    char f[] = {0, 0, 1, 2, 0, 1, 2, 2, 2, 0, 1, 1, 1, 1, 2, 0, 1, 1, 1, 2, 0, 2, 1, 1, 0, 0};
    char i = 0;
    while (i < sizeof(f))
    {
        blink();
        if (f[i] == 0)
        {
            OCR1A = 0;
            tick(tDah);
        }
        if (f[i] == 1)
        {
            OCR1A = fsk;
            tick(tDit);
        }
        if (f[i] == 2)
        {
            OCR1A = fsk;
            tick(tDah);
        }
        blink();
        OCR1A = 0;
        tick(tDit);
        i++;
    }
}

void slope()
{
    char i = 0;
    while (i < 25)
    {
        OCR1A = 255 - i;
        i++;
    }
    while (i > 0)
    {
        i--;
        OCR1A = 255 - i;
    }
}

int main(void)
{
    DDRA = 255;
    blink();
    pwm_init();
    t_unit = 1000;
    fsk = 10;
    id(); // set to fast and ID once
          //fsk=50;//t_unit = 65536; // set to slow for QRSS
    t_unit = 60000;

    while (1)
    {
        ;
        fish();
        id();
    }

    return 1;
}
```

Debut of the AJ4VD QRSS Fish

Finally! After a few years tumbling around in my head, a few months of reading-up on the subject, a few weeks of coding, a few days of bread-boarding, a few hours of building, a few minutes of soldering, and a few seconds of testing I've finally done it - I've created my first QRSS transmitter! I'll describe it in more detail once I finalize the design, but for now an awesome working model. It's all digital, consisting of 2 ICs (an ATTiny44a for the PWM-controlled frequency modulation, and an octal buffer for the pre-amplifier) followed by a simple pi low-pass filter.

My desk is a little messy. I'm hard at work! Actually, I'm thinking of building another desk. I love the glass because I don't have to worry (as much) about fires. That sounds scary, I know.

This is the transmitter. The box is mostly empty space, but it consists of the circuit, an antenna connection, a variable capacitor for center frequency tuning, and a potentiometer for setting the degree of frequency shift modulation.

Yeah, that's a fishy. Specifically a goldfish (the cracker). It's made with a single tone, shifting rapidly (0.5 sec) between tones. So cool. Anyway, I'm outta here for now - getting back to the code! I think I'll try to make a gator next...

Here's the code that makes the fish. It sends my ID quickly, some fish, then my ID in QRSS speed using PWM.

#include <avr/io.h>
#include <util/delay.h>

const int tDit = 270 / 3;
const int tDah = 270;

char fsk;
unsigned long int t_unit;

void delay()
{
    _delay_loop_2(t_unit);
}

void blink()
{
    PORTA ^= (1 << 0);
    PORTA ^= (1 << 1);
    PORTA ^= (1 << 2);
    PORTA ^= (1 << 3);
}

void tick(unsigned long ticks)
{
    while (ticks > 0)
    {
        delay();
        delay();
        ticks--;
    }
}

void pwm_init()
{
    //Output on PA6, OC1A pin (ATTiny44a)
    OCR1A = 0x00;  //enter the pulse width. We will use 0x00 for now, which is 0 power.
    TCCR1A = 0x81; //8-bit, non inverted PWM
    TCCR1B = 1;    //start PWM
}

void set(int freq, int dly)
{
    OCR1A = freq;
    tick(dly);
}

void fish()
{
    char f[] = {0, 0, 0, 4, 5, 3, 6, 2, 7, 1, 5, 6, 8, 1, 8, 1, 8, 1, 8, 1, 8, 2, 7, 3, 6, 2, 7, 1, 8, 1, 8, 4, 5, 2, 3, 6, 7, 0, 0, 0};
    char i = 0;
    while (i < sizeof(f))
    {
        i++;
        OCR1A = 255 - f[i] * 15;
        blink();
        tick(20);
    }
}

void id()
{
    char f[] = {0, 0, 1, 2, 0, 1, 2, 2, 2, 0, 1, 1, 1, 1, 2, 0, 1, 1, 1, 2, 0, 2, 1, 1, 0, 0};
    char i = 0;
    while (i < sizeof(f))
    {
        blink();
        if (f[i] == 0)
        {
            OCR1A = 255;
            tick(tDah);
        }
        if (f[i] == 1)
        {
            OCR1A = 255 - fsk;
            tick(tDit);
        }
        if (f[i] == 2)
        {
            OCR1A = 255 - fsk;
            tick(tDah);
        }
        blink();
        OCR1A = 255;
        tick(tDit);
        i++;
    }
}

void slope()
{
    char i = 0;
    while (i < 25)
    {
        OCR1A = 255 - i;
        i++;
    }
    while (i > 0)
    {
        i--;
        OCR1A = 255 - i;
    }
}

int main(void)
{
    DDRA = 255;
    PORTA ^= (1 << 0);
    PORTA ^= (1 << 1);
    pwm_init();

    t_unit = 2300;
    fsk = 50;
    id(); // set to fast and ID once

    fsk = 50;
    t_unit = 65536; // set to slow for QRSS

    while (1)
    {
        id();
        for (char i = 0; i < 3; i++)
        {
            fish();
        }
    }

    return 1;
}
Markdown source code last modified on January 18th, 2021
---
title: Debut of the AJ4VD QRSS Fish
date: 2010-05-19 19:58:16
tags: python, qrss, old
---

# Debut of the AJ4VD QRSS Fish

__Finally!__ After a few years tumbling around in my head, a few months of reading-up on the subject, a few weeks of coding, a few days of bread-boarding, a few hours of building, a few minutes of soldering, and a few seconds of testing I've finally done it - I've created my first QRSS transmitter! I'll describe it in more detail once I finalize the design, but for now an awesome working model. It's all digital, consisting of 2 ICs (an ATTiny44a for the PWM-controlled frequency modulation, and an octal buffer for the pre-amplifier) followed by a simple pi low-pass filter.

<div class="text-center img-border">

[![](qrss-desk_thumb.jpg)](qrss-desk.jpg)

</div>

__My desk is a little messy.__ I'm hard at work! Actually, I'm thinking of building another desk. I love the glass because I don't have to worry (as much) about fires. That sounds scary, I know.

<div class="text-center img-border">

[![](qrss-transmitter_thumb.jpg)](qrss-transmitter.jpg)

</div>

__This is the transmitter.__ The box is mostly empty space, but it consists of the circuit, an antenna connection, a variable capacitor for center frequency tuning, and a potentiometer for setting the degree of frequency shift modulation.

<div class="text-center img-border">

[![](qrss-fish_thumb.jpg)](qrss-fish.png)

</div>

__Yeah, that's a fishy. __Specifically a goldfish (the cracker). It's made with a single tone, shifting rapidly (0.5 sec) between tones. So cool. Anyway, I'm outta here for now - getting back to the code! I think I'll try to make a gator next...

__Here's the code that makes the fish.__ It sends my ID quickly, some fish, then my ID in QRSS speed using PWM.

```c
#include <avr/io.h>
#include <util/delay.h>

const int tDit = 270 / 3;
const int tDah = 270;

char fsk;
unsigned long int t_unit;

void delay()
{
    _delay_loop_2(t_unit);
}

void blink()
{
    PORTA ^= (1 << 0);
    PORTA ^= (1 << 1);
    PORTA ^= (1 << 2);
    PORTA ^= (1 << 3);
}

void tick(unsigned long ticks)
{
    while (ticks > 0)
    {
        delay();
        delay();
        ticks--;
    }
}

void pwm_init()
{
    //Output on PA6, OC1A pin (ATTiny44a)
    OCR1A = 0x00;  //enter the pulse width. We will use 0x00 for now, which is 0 power.
    TCCR1A = 0x81; //8-bit, non inverted PWM
    TCCR1B = 1;    //start PWM
}

void set(int freq, int dly)
{
    OCR1A = freq;
    tick(dly);
}

void fish()
{
    char f[] = {0, 0, 0, 4, 5, 3, 6, 2, 7, 1, 5, 6, 8, 1, 8, 1, 8, 1, 8, 1, 8, 2, 7, 3, 6, 2, 7, 1, 8, 1, 8, 4, 5, 2, 3, 6, 7, 0, 0, 0};
    char i = 0;
    while (i < sizeof(f))
    {
        i++;
        OCR1A = 255 - f[i] * 15;
        blink();
        tick(20);
    }
}

void id()
{
    char f[] = {0, 0, 1, 2, 0, 1, 2, 2, 2, 0, 1, 1, 1, 1, 2, 0, 1, 1, 1, 2, 0, 2, 1, 1, 0, 0};
    char i = 0;
    while (i < sizeof(f))
    {
        blink();
        if (f[i] == 0)
        {
            OCR1A = 255;
            tick(tDah);
        }
        if (f[i] == 1)
        {
            OCR1A = 255 - fsk;
            tick(tDit);
        }
        if (f[i] == 2)
        {
            OCR1A = 255 - fsk;
            tick(tDah);
        }
        blink();
        OCR1A = 255;
        tick(tDit);
        i++;
    }
}

void slope()
{
    char i = 0;
    while (i < 25)
    {
        OCR1A = 255 - i;
        i++;
    }
    while (i > 0)
    {
        i--;
        OCR1A = 255 - i;
    }
}

int main(void)
{
    DDRA = 255;
    PORTA ^= (1 << 0);
    PORTA ^= (1 << 1);
    pwm_init();

    t_unit = 2300;
    fsk = 50;
    id(); // set to fast and ID once

    fsk = 50;
    t_unit = 65536; // set to slow for QRSS

    while (1)
    {
        id();
        for (char i = 0; i < 3; i++)
        {
            fish();
        }
    }

    return 1;
}
```

Minimal QRSS Transmitter

Success! Amid a bunch of academic exams, psycho-motor tests, and other crazy shenanigans my dental school is putting me through, I managed to do something truly productive! I built a simple QRSS transmitter with an ATTiny44A microcontroller clocked by a 7.04 MHz crystal which generates FSK signals and modulates its own frequency by applying potential to a reverse-biased diode at the base of the crystal, the output (CKOUT) of which is amplified by an octal buffer and sent out through an antenna. As it is, no lowpass filtering is implemented, so noisy harmonics are expected. However for ~2$ of parts this is an effective QRSS transmitter!

I was able to detect these signals VERY strongly at a station ~10 miles from my house. I haven't yet dropped in a 10.140 MHz crystal and tried to get this thing to transmit in the QRSS band, but when I do I hope to get reports from all over the world! This is what it looks like:

The cool thing about this transmitter (aside from the fact that it's so cheap to build) is that it will work with almost any crystal (I think below 20 MHz-ish) - just drop it in the slot and go!

Markdown source code last modified on January 18th, 2021
---
title: Minimal QRSS Transmitter
date: 2010-05-17 11:13:52
tags: circuit, qrss, old
---

# Minimal QRSS Transmitter

__Success!__ Amid a bunch of academic exams, psycho-motor tests, and other crazy shenanigans my dental school is putting me through, I managed to do something truly productive! I built a simple QRSS transmitter with an ATTiny44A microcontroller clocked by a 7.04 MHz crystal which generates FSK signals and modulates its own frequency by applying potential to a reverse-biased diode at the base of the crystal, the output (CKOUT) of which is amplified by an octal buffer and sent out through an antenna. As it is, no lowpass filtering is implemented, so noisy harmonics are expected. However for ~2$ of parts this is an effective QRSS transmitter!

<div class="text-center img-border">

[![](simple_qrss_transmitter_thumb.jpg)](simple_qrss_transmitter.jpg)

</div>

__I was able to detect__ these signals VERY strongly at a station ~10 miles from my house. I haven't yet dropped in a 10.140 MHz crystal and tried to get this thing to transmit in the QRSS band, but when I do I hope to get reports from all over the world! This is what it looks like:

<div class="text-center img-border">

[![](aj4vd_thumb.jpg)](aj4vd.jpg)

</div>

__The cool thing__ about this transmitter (aside from the fact that it's so cheap to build) is that it will work with almost any crystal (I think below 20 MHz-ish) - just drop it in the slot and go!

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