Arduino based DRSSTC or SSTC Modulator

Reaching, Thu Jul 03 2014, 11:16AM

Hi there.

Ive been working on a new drsstc modulator and thought this would be interesting for you guys.

the modulator basically is a simple arduino board (i.e mega 2560 or even the nano V3), with a 20x4 digit display and some sort of keypad to control it.
there are just a few external components needed so you dont even have to solder things together if you dont want to.

i just thought it would be cool to completely modulate everything in software instead of using external components.

there are 2 modes of operation.

first mode is the "manual" mode,. here you can control the on and the off time within restricted ranges you set in the code.
for example: if you set 250microseconds on time in the code, the modulator is not be able to do more than 250microseconds.. no need to grab your screwdriver and turn a trimpot around and measure the output. just write it in the code and you done^^

the display shows you the on and the off time in realtime, calculates the frequency in hertz and calculates the duty cycle in %

the output is either inverting or non inverting, depending on the electronics you want to use to send the signal to your coil.

______________________
the music mode is by far the best mode i think^^ you just put an audiosignal on the analog input, and the modulator will do the rest.(square or sinusodial or anything else)
with a simple routine, the software will find the zero crossing point, turn the analog signal into a square wave and then adds the ontime to the signal.
thats it.
the volume will be displayed in percent, so you know if your audio input is loud enough. the ontime is displayed and the adjusted mode.

Its still a work in progress but ive been working on it for days now and its ready to play the first music on a drsstc :)
ive made a video of the modulator, but its in german, so, just take a look, maybe i will explain it in english on the next video, but i have a bad accent, ^^

Link2

If this all works fine, i will add a third mode, the midi input cheesey

Greetz,
Martin
Re: Arduino based DRSSTC or SSTC Modulator
DerStrom8, Thu Jul 03 2014, 12:36PM

Excellent work, thanks! I'm currently building my first DRSSTC and I am using an Arduino Uno as the controller. I currently only have it set up to adjust frequency and duty cycle, but was also going to add some zero-crossing detector code for audio input. Mine won't be as fancy as yours, for sure, but your project is definitely going to be an inspiration.

Cheers!
Matt
Re: Arduino based DRSSTC or SSTC Modulator
Graham Armitage, Thu Jul 03 2014, 02:29PM

This is great. The first modulator I built used the Arduino and I continue to experiment with it. I love the idea of being able to experiment via code rather than circuitry. Never did anything this fancy though - very nice work. A MIDI option would be the cherry on the top.
Re: Arduino based DRSSTC or SSTC Modulator
Reaching, Thu Jul 03 2014, 04:35PM

hey
Yes, i thought that too.

So im working hard on a midi mode right now... maybe in a few days, hihi^^ cheesey

Greetz,
Martin
Re: Arduino based DRSSTC or SSTC Modulator
Sigurthr, Fri Jul 04 2014, 03:12AM

Very nice work, that code must be quite impressive! Loneoceans has a brilliant SSTC interrupter that runs on arduino IDE via a ATTiny85 chip, and I've reworked his software to suit my needs (adding a CW mode and adjusted the PRF and PW range) but getting either of our versions to work as nicely as yours for a DRSSTC would be a stretch. I'm no programmer though, but yours looks beautiful!
Re: Arduino based DRSSTC or SSTC Modulator
Reaching, Fri Jul 04 2014, 07:16PM

Hi

Did some serious tests today cheesey First light with a small drsstc was quite impressive

Link2

Cheers

Martin
Re: Arduino based DRSSTC or SSTC Modulator
DerStrom8, Fri Jul 04 2014, 08:42PM

Reaching wrote ...

Hi

Did some serious tests today cheesey First light with a small drsstc was quite impressive

Link2

Cheers

Martin

Very impressive! Nicely done! Do you plan to release the source code, or is it your own little secret? wink

I look forward to seeing more!

Regards,
Matt

EDIT: I stumbled across this in my work, thought I'd share it. May serve as some inspiration!
Link2
Re: Arduino based DRSSTC or SSTC Modulator
Vitalii, Mon Sept 01 2014, 02:50PM

Hi!
Can you share your source code and schematic with the community.