Posts Tagged ‘midi’

Another Arduino project – The hardware..

June 12, 2016

So I’ve been busy accumulating hardware for my latest Arduino based project. I am using two different platforms. I am using an Arduino Uno with an SD card shield and an 16×2 LCD display initially because I can hook up the midi parts to it directly as I have done so in the past. The problem with it is that it does not have a lot of program memory and is very limited on data memory so while it’s a good platform to start experimenting with, it remains to be seen how far  can get using it. On the plus side, it does have on chip EEPROM so it is possible to save settings across power ups.

Part two of the project (or it may become the only part, who knows) will use an Arduino Due. The Due has a LOT more program and data memory and runs over five times faster than the Uno (84Mhz vs 16 Mhz). The down side is a) no EEPROM so that’s something I’d have to add externally and b) it’s a 3.3 volt device so no hooking up the MIDI directly to the Due pins like I can with the Uno. That means I’ll have to build some sort of Midi shield for it to buffer the voltages both in and out. I cannot even use anything comercial as I need a custom number of MIDI ports for my little project.

 

This is the UNO hardware stack so far:

UnoStack

All the Hardware is from Adafruit. The LCD display itslf comes pre assembled except for header pins. The Shield it is mounted to is a kit. I added the sockets that the chip is in myself since I don’t like soldering directly to IC chips, too easy to kill them with the heat!

Programming it was pretty easy as all the information you need, as well as a handy dandy library for the LCD and buttons is available via the Adafruit web site.

And this is the DUE stack:

DueStack.JPG

Can’t recall where I got the DUE from but the LCD and shields that that is mounted to are from eBay (vendor is coldtears). Came from Hong Kong, took about a week to get here so not too bad shipping wise. The LCD software uses a library from some guy on the web but it works very well and includes a demo. I did have to change a setting in the demo code to match the LCD screen (device type info) but the biggest problem I had was the Arduino IDE. Initially, it would not upload to the DUE and I was getting some errors during the compiles as well. Eventually I found that some functionality of the IDE to support the DUE that used to be included now has to be added separately. In addition there was a syntax error in one of the config files that was causing the warnings during the compile. Also the thrid party library I was using for the LCD had a .github directory in the library structure that should not have been there.

Once I tidied everything up though, the LCD part worked great.

Both the shield the LDC sits on and the LCD card itself have an SD card slot. The one on the shield is disabled by default so I chose to use the one on the LCD. It’s not very accessible but that’s not too much of a problem right now. The hardest part was figuring out what pin on the DUE corresponded to the Chip Select pin for the SD card reader. After unplugging things and following circuit board traces and digging around on the internet, I figured out it was pin 53. I changed the example SD card  program in the Arduino IDE and tried it and it worked just fine.

 

So now I’ve got two hardware stack basically up and running, albeit without the MIDI part yet. Time to start programming (and researching the MIDI hardware for the DUE)!

 

 

Stomp box – one last change…

October 15, 2013

One thing that had bothered me was that I had no way to indicate to the user (that would be me!) which volume mode the box was in (normal volume or solo level). I had thought about flashing the LEDs but the code would get real messy and I thought it would be confusing visually anyway. So in the end I bit the bullet, accepted there’s only so much you can do with two LEDs and added a third one. A simple code change and it was good to go. I just need to drill a hole for the new LED and glue it in place now and I really am all done this time.

Wireless Midi – The Plan…

April 29, 2013

So, with the wireless midi setup working, obviously I need more!

One issue is that the Lucina does not send volume info via midi so I have no volume control. What I can do though is control the volume on the effects unit that is in my rack setup and my normal way of setting the rack up is to feed the output from the synth module into the effects unit and then to the PA.

Reading the midibridge doc it seems I can in fact setup multiple connections to the wireless midi which would be on the iPad for now (although each iPod can only initiate one session) so I figured I could hook up my midi foot controller using a similar setup and put the keytar and synth module on one midi channel and the controller and effects unit on another channel and it should all work just fine! Also, I can use the foot controller to change effects settings on the effects unit as well as control the volume and use the keytar to change patch settings on the synth module.

The only down side so far is that my current foot controller is mains powered so it’s not really wireless totally yet but I could live with that for now! At least I’d only need a power cable going to the foot controller instead of a power cable and midi cable as now.

Here’s a picture of ‘the plan’…:

WirelesMidi2

Wireless Midi

April 21, 2013

I am a ‘tinkerer’ and a musician of sorts. I play for fun. I’d LIKE to play for money but my skill level being what it is…. ah well! As well as my regular keyboard I have a ‘keytar’, actually a Roland Lucina that I play at gigs sometimes instead of the main keyboard. It’s a lot smaller and easier to carry for a start. I also built myself a rack unit some time ago to augment the both the keyboard and keytar sound.

One think I’ve always wanted to do with the keytar is set it up to use wireless so I could be ‘cable free since it can run from batteries. However commercial (and decent) wireless sound systems get pretty expensive and so does midi. But, me being a tinkerer, I got to wondering if I could create a wireless midi using (mostly) what I already had, mainly an iPad and an iPod!

First off I found a app called Midibridge that would connect various midi inputs and outputs to others in the same device, including a wireless midi connection to the same app on anther device!

So now I needed some hardware to get the midi from the keytar into the iPod and from the iPad out to the rack synth. Enter the iRig midi interface. I went for this one over others because it has a charging port as well so you can charge the iPod/iPad while it is in use.

For this to work I need a wireless network.  Now you might say that I cannot guarantee the presence of a wireless network anywhere but the thing is, you don’t need and actual internet connection for a wireless router to create a wireless network so the plan is to get a wireless router and set it up to create a private ‘non internet’ network where ever I am playing. Wireless routers have plenty of range too so I should not have to worry about that which will let me roam pretty freely with the keytar.

So far I have only tried this at home using my home network and a single iRig midi interface connected to an iPod to drive an app on the iPad but it seems to works fine with very little latency so this ‘might’ actually work (unusual for me!).

This shows how I plan to make all this work:

WirelesMidi

The iPad (or another iPod) and router will sit by the rack synth on the mains power supply. The iPod will sit in a pocket or something on the keytar strap and run off the internal batteries or some sort of battery powered external supply (I’m sure there are some out there).

Hiccups so far. My iPod is a 2nd generation one and the highest level of iOS you can install on there is 4.2.1. Seems the iRig (and other similar devices) need iOS 4.3 or higher (of course). It turns out the kid has a 4th gen iPod he is selling because he got an iPhone so I am buying that off him (actually he still owes me for the iPhone as I paid for it initially so I’m letting him off ‘some’ of the bill’).

I had some trouble getting the Midibridge software to see the wireless midi components on the iPod initially (the iPad was fine). Rebooting it fixed that though.