Propeller Multimedia Board (Audio/Video Board)
6581
Posts: 132
Hi,
I've designed a little board for the propeller in the last 2 days.
This board is made for audio and video applications - such as running the
SIDCog + audio visualization for live performances and similar stuff.
The board is an open source, non-commercial project.
What do you think about it? Any suggestions?
Technical specifications:
- 5 x RCA connectors (chinch) for Audio I/O
- VGA-Connector
- Storage connector
- 3.3V and 5V voltage regulator
http://syso.name/pmb/
PCB Rendering (sorry, not all components in 3D):
PS: Sorry, the image is low-res for now. Got to re-upload it later.
I've designed a little board for the propeller in the last 2 days.
This board is made for audio and video applications - such as running the
SIDCog + audio visualization for live performances and similar stuff.
The board is an open source, non-commercial project.
What do you think about it? Any suggestions?
Technical specifications:
- 5 x RCA connectors (chinch) for Audio I/O
- VGA-Connector
- Storage connector
- 3.3V and 5V voltage regulator
http://syso.name/pmb/
PCB Rendering (sorry, not all components in 3D):
PS: Sorry, the image is low-res for now. Got to re-upload it later.
Comments
Bean
Plus, if one wants to, sounds can be made with that circuit as well as TV signals.
There are 100nF on the bottom side directly under the TQFP44 (connected
directly using vias). From my experience SD works without any problems
without pull-ups (clear signal on oscilloscope, technically okay).
Okay, this can be done easily.
PMB + MIDI in + 6*SIDcog = AWESOME.
It's important to use cog 0 for audio output to reduce noise/distortion as much as possible.
(For live performance it might be necessary to have an external DAC for best results)
JonnyMac has made a commercial audio playback device using just the propeller(No DAC). He might be the right person to talk to if you want any advice.
/Johannes
I've had problems using that style of SD card slot - it's very difficult to rework if there's a problem. I've had better luck with This one.
Other than that (and the caps that JonnyMac et. al. have mentioned), looks nice to me.
Thanks Johannes!
I'll just try it out as soon the first batch of pcb's (3 pieces) arrive.
Is there any news on a stereo sid cog or do I still have to use 6
cores for 6 mono channels?
Btw: I'm thinking of making a MOS6581-compatible DIL-28 replacement
using your SIDcog (with the standard parallel data interface). What do you think?
The TO-92 is used for inverting the /RESET line.
It shouldn't be missing anything - it's based on FTDI's datasheet
schematics, so I guess that should be right. Tell me if I'm wrong.
I'll check out the availability of the SD card socket - if it's available
here, I'll replace it as soon as possible. Thanks for your suggestion.
It should be fairly easy to write back the sound data each sample to HUB ram and then make a mixer-cog to mix the samples from up to 6 SIDcogs into a stereo signal with independent panning. You don't even have to worry about synchronizations between the cogs since each sample takes EXACTLY the same amount of cycles and each cog runs in parallel with the same clock source.
Feel free to improve or add functionality to SIDcog as you like. I haven't updated the code for half a year.
SIDcog ToDo list:
1. Add ADSR bug
2. Validations of the envelope timings
3. Improve Combined waveforms
1 and 2 needs a real SID playing the exact same data as SIDcog and then compare the results against each other.
I would love to have a replacement SID. It could even be programmed with other sound chips like the AY38910 and NES. Why not the SID + AY38910 + NES at the same time?
Yep, kind of at least.. I didn't update the site for a while now.
There is a video:
http://blip.tv/file/4212650
Sorry for the bad video quality - blip.tv seems to convert it to a low quality video
and YouTube sucks, cause it wants to validate my YouTube account via SMS.
You see all of the SID registers on the VGA output (for debugging purposes) and
a visual representation of the Cutoff and Resonance values.
@Ahle2: This seems to be quite interresting: http://ploguechipsounds.blogspot.com/2010/03/sid-6581r3-adsr-tables-up-close.html
Thanks. I'm using Eagle for designing the PCB, Eagle3D scripts to generate PovRay data (customized version) and MegaPOV (modified version) with radiosity and finish fixed. I'll probably publish the scripts needed soon, if I'll find somebody to cleanup the includes.
That is certainly going to help me understanding the envelope part of the SID better.
Btw, I like the demo of your PMB.
The second tune is already in my collection.
Btw, are you using my serial driven SIDcog solution in the video?
I have a Linux version of application as well, if you are interested.
Got to check the name later. I'd enjoy to get the linux version of the serial
player! Are you planing to publish your source code?
Note that this is just some experimental prototype
This is why it looks so boring. What do you think?
Got to cut the LCD and 7-segment holes and add some leds.
Then I'll post some pictures of a working prototype
Sorry, I didn't make any videos of the prototype. I've already "destroyed"
the prototype and now I'm working on PCBs for it. I'll post here as soon
I have the new version built
running soon. There seems to be some bug in the version.
It's going to be finished soon (hopefully)! I will post some pictures then.
I've managed to get multiple instances of SIDCog working (it needs
a little delay between starting another SIDCog. Thanks Ahle for your
great work!
So you finally got multiply instances of SIDcog to work at the same time?
I'm really loking forward to see this in action when it's finished.
/ Ahle2
Yep, that's right. Today in the morning (06:00 AM) I've started to drill
some holes into the 2 PCBs to connect them together and discovered
that my drill layout differs on 2 boards.. Now I have to re-work the
2nd PCB in order to get it up and running. I'll post some pictures
as soon as it's finished.
PS: I've managed to get 4 SIDcogs up and running without any problems
(running in a 5.1-like setup) and playing one SID dump with the detuning
effect used in the stereo SID example + hard set low-pass filter for a
"damping" effect on the rear loudspeakers. This gives a nice depth effect
to chiptunes
Another quite nice thing is: Detune front left by 1.0, Detune front right by 1.006,
detune rear channels by 2.006 - this means that the rear speakers will be exactly
one octave lower.
Does somebody have a organ to put the synthesizer in it (inspired by Linus
Akesson's Chipophone)? I guess this could be a lot of fun with a total of e.g.
12 oscillators ;-)
That's two more oscillators than my precious Yamaha An1x.