Media Keys And Alarm Buzzer Idea

[chris_c]

I have my right shoulder configured as a XF86AudioNext key for when I'm on the go with cmus in "low power" mode, however this is slightly sub-optimal as its all too easy to jog the shoulder button when on the go...

As the pandora *can* be woken up from its OFF state by its alarm, and as the pandoras sound output can be physically turned down, it would be handy to have some kind of buzzer thats always at a fixed volume - some kind of cheap nasty piezo would be fine for this

packaged all together with an ipod like hold switch (to inhibit the keys) and you'd have quite a nice satellite control system you could hang outside your inside jacket pocket while your pandora nestles comfortably in safety...

I've had a bunch of experience working with embedded controllers but almost none working with USB - about time!

does anyone know of a USB2.0 capable micro controller that they know doesn't hang the Pandora's usb subsystem ?

AFAICS the usb OTG seems to be only about com's - but could it be press ganged into use ? are there other otg "modes" or even a micro controller that can be connected via OTG

any thoughts and ideas and tips on devices/components at this stage is *most* welcome! - short small not standard usb plugs, micro controllers you know work with the pandora's USB2.0 etc etc...

 

[CPUnltd]

a bluetooth media remote should do the job... here's a good option...

http://www.amazon.com/Palm-Sized-Wireless-Bluetooth-Keyboard-Touchpad/dp/tags-on-product/B002YX1M3U

 

[chris_c]

Way, way too big for what I had in mind and no buzzer! I'm thinking something not much bigger than 6 or so small keys....

 

[iampanis]

It won't give you a buzzer, but you could just write the software to make the hold switch already on the Pandora actually do something.

 

[CPUnltd]

I'm sure the buzzer can be done via the OS... working on a smaller option for the media remote though...

 

[chris_c]

no because you could have the sound turned right down with the *physical* volume control - which has nothing to do with software....

and has it not occurred to you that another motivation for this project, is that I enjoy building useful electronics..?

 

[chris_c]

http://www.pjrc.com/teensy/usb_keyboard.html something like this with 1/2 the buzzers and the buzzer connected to the keyboard "caps lock LED"

My alarm daemon could then find the custom keyboard device and just set the caps lock led to make a noise....


anyone know if Pandora's usb works ok with the teensy ?

 

[CPUnltd]

I see that you have a passion for such... When you make something that compliments the Pandora well, I'll buy one for myself and like 50 for my store...

 

[chris_c]

omg nooo, you mean I'll have to put it in a nice box and everything :-o

 

[CPUnltd]

I can make the nice box... just get me a toy that works and works well...

 

[chris_c]

well.... £20 and 1-3 weeks wait, couldn't find a breakout board for a ATMEGA32U4 from the UK!

the atmega 32u4 as a separate component can be had for as little as £3.50 as a one off, so if made with a custom circuit board the buzzer and 6 micro switches and a slide switch will probably cost more than the controller!

It would be interesting to see what a small run of say 100 populated boards would cost, a number board manufacturers can even pre program the micro controller now a days...

 

[chris_c]

ok so good news and bad news

first off my teensy usb 2.0 arrived and its a super little device! super fast downloading of your code to the micro controller - which is quite a capable little machine in its own right! (beats the arduino hands down but then that is only slow serial over usb...)

There are some simple usb HID examples that are easy to get to grips with, as ever avr make nice chips!

so now the not so happy news - getting it working with the Pandora’s *ridiculously* picky usb host was a no go.... although its a full speed USB 2.0 device it won't revert to hi-speed (sadly) so I went of to my neighbour (Mr ASDA) and purchased a nice 4 port usb Maxel hub for the princely sum of £4

This hub has 5 cables 3, with full sized usb sockets, and 1 mini plug as well as the host plug, after denuding it of its case I decided solder on a longer cable to the host side and cut off the 3 full sized usb sockets leaving the mini plug,

Mainly because of the 16 solder pads for the output the usb hub board is about 50% larger than the teensy board! however I should be able to get it into the project box which is much larger than I would have liked but seemed the best fit when I was in Maplins, and OMG the price of micro switches, I couldn't find any surface mount types so had to get some barrel type, so a few drill holes and they should fit into the box quite neatly.

So next session is investigating the best way to send data from the host to my device (to activate the piezo buzzer) - the keyboard stuff is dead easy and has basically been done for me already with one of the teesey examples...

 

[mcobit]

Why not use a usbkeyboard and strip down everything except the keyboardcontroler from it? Then wire some microswitches to the controller directly and package everything in a nice case. Voila, everything you want without an expensive microcontrollerboard...

Edit: You can even use the multimediakeys, that some keyboards supply.

I think I will hack up something like this just for fun

 

[chris_c]

Why not use a usbkeyboard and strip down everything except the keyboardcontroler from it? Then wire some microswitches to the controller directly and package everything in a nice case. Voila, everything you want without an expensive microcontrollerboard...


Edit: You can even use the multimediakeys, that some keyboards supply.

I think I will hack up something like this just for fun

microcontroller aint expensive! something like a teensy is $16 and well worth it! and far more fun! (besides the keyboard controller *is* a microcontroller!)

I also want to implement an alarm buzzer, disable switch and at a later date some other functionality - as I'm able to write software for the controller I can also work in a kind of deep sleep mode to save power, either the buttons or incoming usb can generate an interrupt which can "wake up" the rest of the controller