Forums

wireless audio device

Started by Programmer March 25, 2005
This isn't directly related to DSP as of now, but at the same I'm hoping 
that someone in here may be able to help (after all it's music related!)

I've been gearing up to take on a new hobby project, building a wireless 
MIDI controller.

I've done a fair bit of research and I am pretty straight on what parts I 
need for the task and so on. 

The one roadblock I've hit is making the setup wireless. The options I've 
explored are mainly Bluetooth and RF with the latter looking to be more 
promising.

Problem is, I'm so new to this that I'm not certain what to do next. I'm 
aware of how to program a PIC chip to read output from a sensor, and in 
turn translate that data and send it over a serial MIDI connection to my 
computer to have it trigger the said note.

I'm hoping that someone could give me some idea(s) as to how to accomplish 
this wirelessly? What parts I will need, what a basic schematic might look 
like? 

My device will most likely have 12-14 buttons that will need to send a note 
a controller change upon being pressed. Velocity register through a piezo 
or FSR is also likely.

I've done some searching around already but couldent find anything in 
practice, mostly just theroy of how it "should" work.

It woulde be especially helpfull if anyone has, or knows of a working 
controller similar to the above mentioned (tutorial or other).

Many thanks in advance-
Programmer wrote:
> This isn't directly related to DSP as of now, but at the same I'm hoping > that someone in here may be able to help (after all it's music related!) > > I've been gearing up to take on a new hobby project, building a wireless > MIDI controller. > > I've done a fair bit of research and I am pretty straight on what parts I > need for the task and so on. > > The one roadblock I've hit is making the setup wireless. The options I've > explored are mainly Bluetooth and RF with the latter looking to be more > promising.
Bluetooth _is_ RF -- by RF do you mean some simple protocol rather than the tres-complex Bluetooth? You may also want to look at zig-bee -- I know little about it, other than it is a Bluetooth alternative. Further, have you considered IrDA? It's restricted to line-of-sight to a much greater extent than an RF-based method like Bluetooth, Zig-Bee or your "RF" would be, but it'll be much simpler to implement from scratch.
> > Problem is, I'm so new to this that I'm not certain what to do next. I'm > aware of how to program a PIC chip to read output from a sensor, and in > turn translate that data and send it over a serial MIDI connection to my > computer to have it trigger the said note. > > I'm hoping that someone could give me some idea(s) as to how to accomplish > this wirelessly? What parts I will need, what a basic schematic might look > like? > > My device will most likely have 12-14 buttons that will need to send a note > a controller change upon being pressed. Velocity register through a piezo > or FSR is also likely. > > I've done some searching around already but couldent find anything in > practice, mostly just theroy of how it "should" work. > > It woulde be especially helpfull if anyone has, or knows of a working > controller similar to the above mentioned (tutorial or other). > > Many thanks in advance-
If you don't know anything about RF design I would strongly suggest that you find yourself a module that will talk to a PIC and leave all the RF stuff to someone else. Try sci.electronics.basic or sci.electronics.design for pointers on modules. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com
Programmer <aprogrammer@hotmail.com> writes:

> This isn't directly related to DSP as of now, but at the same I'm hoping > that someone in here may be able to help (after all it's music related!) > > I've been gearing up to take on a new hobby project, building a wireless > MIDI controller. > [...]
You might want to scout around to see if you can get from here to there without much effort first. I know there are USB versions of MIDI, and I think someone makes a wireless USB interface. -- Randy Yates Sony Ericsson Mobile Communications Research Triangle Park, NC, USA randy.yates@sonyericsson.com, 919-472-1124
Programmer wrote:
> This isn't directly related to DSP as of now, but at the same I'm hoping > that someone in here may be able to help (after all it's music related!) > > I've been gearing up to take on a new hobby project, building a wireless > MIDI controller. > > I've done a fair bit of research and I am pretty straight on what parts I > need for the task and so on. > > The one roadblock I've hit is making the setup wireless. The options I've > explored are mainly Bluetooth and RF with the latter looking to be more > promising. > > Problem is, I'm so new to this that I'm not certain what to do next. I'm > aware of how to program a PIC chip to read output from a sensor, and in > turn translate that data and send it over a serial MIDI connection to my > computer to have it trigger the said note. > > I'm hoping that someone could give me some idea(s) as to how to accomplish > this wirelessly? What parts I will need, what a basic schematic might look > like? > > My device will most likely have 12-14 buttons that will need to send a note > a controller change upon being pressed. Velocity register through a piezo > or FSR is also likely. > > I've done some searching around already but couldent find anything in > practice, mostly just theroy of how it "should" work. > > It woulde be especially helpfull if anyone has, or knows of a working > controller similar to the above mentioned (tutorial or other). > > Many thanks in advance-
So how many groups did you target with your multiple post? Couldn't you have at least cross-posted? Honestly. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com
On 25 Mar 2005 14:00:04 -0500, Randy Yates
<randy.yates@sonyericsson.com> wrote:

>Programmer <aprogrammer@hotmail.com> writes: > >> This isn't directly related to DSP as of now, but at the same I'm hoping >> that someone in here may be able to help (after all it's music related!) >> >> I've been gearing up to take on a new hobby project, building a wireless >> MIDI controller. >> [...] > >You might want to scout around to see if you can get from here to there >without much effort first. I know there are USB versions of MIDI, and I >think someone makes a wireless USB interface.
That's the easy route, but you'll be at the mercy of the delays associated with the MAC and transport mechanisms. If there aren't many other similar devices contending for the channel you may be okay and it's certainly the easiest and most obvious thing to try. For music, especially if you want to play a device somewhere else in real-time from a wireless user interface, the delay issues are probably the biggest problem to solve if your application is sensitive to them. My understanding is that Gibson's Magic system used an existing PHY (T-100 ethernet, IIRC) with their own MAC in order to make sure the delay issues were handled adequately. Having your PIC talk to a USB interface and then just plugging in a WUSB adapter on each end should be easy enough to experiment with. The next best thing might be having the PIC talk directly to a BT or WLAN device through a PCMCIA i/f, the benefit there being that you've taken the USB stuff out of the loop...a small change but perhaps enough if it doesn't work well enough with them in the loop. Eric Jacobsen Minister of Algorithms, Intel Corp. My opinions may not be Intel's opinions. http://www.ericjacobsen.org
"Eric Jacobsen" <eric.jacobsen@ieee.org> schrieb im Newsbeitrag 
news:424495d4.435491687@news.west.cox.net...

> For music, especially if you want to play a device somewhere else in > real-time from a wireless user interface, the delay issues are > probably the biggest problem to solve if your application is sensitive > to them. My understanding is that Gibson's Magic system used an > existing PHY (T-100 ethernet, IIRC) with their own MAC in order to > make sure the delay issues were handled adequately.
I think latency is not THAT much of a problem with MIDI. I have developed a network-midi-driver which runs on top of UDP and I have not yet seen too bad latency (obviously depending on the load of the network-port which is used) But I'm really not sure how much latency is introduced by technologies like WIFI or Bluetooth which comes from modulation / demodulation. So if the original poster would be using WIFI, he might not need to write a WIN32 device-driver, as my driver would work out of the box with a WIFI-device as well. Problem with WIFI might be the higher power-requirements. If he is looking for a portable device which he wants to attach to a "wearable" midi-keyboard for live-gigging, then I'd say batteries are not a good option for WIFI applications ;-) Tobias
On Thu, 31 Mar 2005 16:08:03 +0200, "Tobias Erichsen"
<t.erichsen@gmx.de> wrote:

> >"Eric Jacobsen" <eric.jacobsen@ieee.org> schrieb im Newsbeitrag >news:424495d4.435491687@news.west.cox.net... > >> For music, especially if you want to play a device somewhere else in >> real-time from a wireless user interface, the delay issues are >> probably the biggest problem to solve if your application is sensitive >> to them. My understanding is that Gibson's Magic system used an >> existing PHY (T-100 ethernet, IIRC) with their own MAC in order to >> make sure the delay issues were handled adequately. > >I think latency is not THAT much of a problem with MIDI. I have developed >a network-midi-driver which runs on top of UDP and I have not yet seen >too bad latency (obviously depending on the load of the network-port >which is used) > >But I'm really not sure how much latency is introduced by technologies >like WIFI or Bluetooth which comes from modulation / demodulation.
Not much of the delay comes from the PHY (although some does), most of it comes from the MAC and the protocols used. BT is designed to have less of this, but suffers a range restriction.
>So if the original poster would be using WIFI, he might not need to >write a WIN32 device-driver, as my driver would work out of the >box with a WIFI-device as well. > >Problem with WIFI might be the higher power-requirements. If he is >looking for a portable device which he wants to attach to a "wearable" >midi-keyboard for live-gigging, then I'd say batteries are not a good >option for WIFI applications ;-)
How long is the gig expected to last? Current WiFi NICS aren't that bad compared to some devices. Not something you'd want to use all day on your PDA, but a keyboard is big enough to support a battery sufficient to run a NIC for a looooong time. Eric Jacobsen Minister of Algorithms, Intel Corp. My opinions may not be Intel's opinions. http://www.ericjacobsen.org
> >Problem with WIFI might be the higher power-requirements. If he is > >looking for a portable device which he wants to attach to a "wearable" > >midi-keyboard for live-gigging, then I'd say batteries are not a good > >option for WIFI applications ;-) > > How long is the gig expected to last? Current WiFi NICS aren't that > bad compared to some devices. Not something you'd want to use all > day on your PDA, but a keyboard is big enough to support a battery > sufficient to run a NIC for a looooong time.
I know it's a bit late but I've been out of the loop for a loooonnnggg time... My PDA (Palm Tungsten) can run for several hours with the WiFi turned on. I can sit on the couch at home and log onto my Wireless netowrk, and also run PPTP software (which does a reasonably CPU intensive encryption) over the top of that. I surfed the web on it for about 3 hours from a full charge and it was claiming it was only down to about 60% power when I finished. The Palm has a tiny little battery in it. Something the size of a keyboard would support a battery that would run for days at low power... assuming that you dont' want the full range of the WiFi. YMMV however. A