Help me choose the right uC
Vern
Posts: 75
First off let me say that I would prefer to stick with parallax products for this project. I am however open to other suggestions if that is what is needed.
Ok so basically I want to build a wristband that you can store 4 or more wav files on (minimum 4) and each wav file can be played with the push of a button or button combo. It should fit in a standard sized sweat wristband and will need to have a way to store the files (I'm think a microSD card for ease of uploading new sound files). It will need a single speaker that can be driven to be loud enough to be audible in everyday situations, ie you should be able to hear it over normal conversation volume.
Is there a premade board out there that will meet my needs? Or am I going to make my first foray into making a custom PCB? I've already searched the OBEX and was happy to see most of what I need is already there to accomplish the software side of things. The biggest hurdle I think is going to be cramming it all into the wristband, hence why I need to keep things small as possible. Also power is an issue I have yet to work out. I'm hoping to power everything from either a rechargeable cell or perhaps just some watch batteries.
Any and all ideas are welcomed, I really just need a starting point for the micro, lets shoot to keep the size under 3-4cm square.
Ok so basically I want to build a wristband that you can store 4 or more wav files on (minimum 4) and each wav file can be played with the push of a button or button combo. It should fit in a standard sized sweat wristband and will need to have a way to store the files (I'm think a microSD card for ease of uploading new sound files). It will need a single speaker that can be driven to be loud enough to be audible in everyday situations, ie you should be able to hear it over normal conversation volume.
Is there a premade board out there that will meet my needs? Or am I going to make my first foray into making a custom PCB? I've already searched the OBEX and was happy to see most of what I need is already there to accomplish the software side of things. The biggest hurdle I think is going to be cramming it all into the wristband, hence why I need to keep things small as possible. Also power is an issue I have yet to work out. I'm hoping to power everything from either a rechargeable cell or perhaps just some watch batteries.
Any and all ideas are welcomed, I really just need a starting point for the micro, lets shoot to keep the size under 3-4cm square.
Comments
I have a few PCBs left for this revision if you want one. The completed unit will sell for $99 when it's finished.
How small is just the board? If possible could you also tell me the dimensions of the battery. Would you be willing to sell me just the board+battery.
Also as a side note, I just decided the title of my post is inaccurate, I really want to use the propeller. Its more like, help me find hardware that will work so I don't have to design my own board because I'm not sure I can. hahaha!
http://arduino.cc/en/Main/ArduinoBoardLilyPad
The LilyPad is open source, you could start with that design, and modify it as necessary to build a Propeller version, if that's the way you wanted to go.
Whatever board you settle on, you could use some of the LillyPad peripherals that are already available, like battery holders,etc.
Sparkfun sells a bunch of them: http://www.sparkfun.com/categories/204
The Lillypad stuff looks good for sewing into clothes - all I've ever done is sewn buttons.
Kevin: I knew about the lilypad but I never thought as using it as a starting point to make a propeller version. Thats a great idea! Then as you said there would be prebuilt linkable peripherals.
Jazzed: Me to on the buttons. But hey, I'm sure I'll figure it out after sewing my thumb to the project a few times.
McTrivia had two products that would have been ideal: The Propmodule and Propmod 1x1. They were both sold through Gadget Gangster on this page (propmodule) and on this page (propmod 1x1), but McTrivia no longer makes them. I have used the Propmod 1x1 for the basis of my Polar Bear Plungelogger and with a few modifications, I have a uSD card piggybacked onto it. You can get a 1.2" square "propeller CPU module" from the center of a protoboard as well with a little bit of cutting.
I am working on something with similar concepts. Attached is a graphic of my brainstorming for a stackup that goes into a Polycase WC-20 Nema rated case for a current project for my work. I have a little bit more room than you, but will be stacking up roughly the same components: uOLED 128 display, Propeller CPU (either my M44D40+ or the center of a protoboard), a 3.7v, 900mah LiPo battery, XBee radio, and a tilt switch.
SpinSocket-Flash is available for battery use and 4MB of Flash memory.
The battery can go as low as 1.2VDC before the Propeller stops working.
The attachment shows 6 battery capable modules. 3 with flash and 3 without.
Modules can also be powered with 4.5V with an optional LM1117 LDO regulator.
I have and SD Card design on my computer but haven't had time to produce it yet.
Cute!