08/20/2014 at 03:28 •
Just in time for the deadline, I finally filmed and uploaded the introductory video to YouTube and linked everything up. Hopefully I managed to get it right :)
First time I've done a YouTube Video (or any video for that matter) and I know its rough compared to others, but hey got it all in one take.
I plan on uploading some more content soon around the teardown of the display, breadboarding the propeller, and getting started getting video from it to the display. Now that I've got all of the bits and bobs here I can already see that everything should come together quite well leaving just enough room for a nice salvaged battery from an old cell phone.
I just hope that I can come somewhat close to some of the example outputs I've seen done by the propeller, but have yet to find code for. Right now I'm fighting getting the propeller to work with Ubuntu 14.04, but more on that later as well once I get it all working.
Any tips or code links would be appreciated as right now the repo is a bit empty. At least it is there and it will start having code just as soon as I get some working :).
08/11/2014 at 02:05 •
Tested the screen out with a standard blue ray player and was quite impressed at the output resolution for a simple cheap $15 display. Nice crisp colors and lines for the size.
Got the screen torn down and started marking out the IC's, connectors, and what connections go where as well as what they do. I've uploaded a preliminary image showing what I've identified so far.
Got my parts list put together for Digikey and have the propeller ordered. Didn't bother ordering the resistors as I already have those lying around someplace. I also didn't order the Crystal as I missed it in my design originally, hope I have one lying around :)
Validated that there is JUST enough room inside the case that the display came in to reuse it and basically dead bug all of the parts directly in place. Got some pictures of the internals too that I will post once I transfer them from my phone to my computer.
Finally, I setup the GitHub repo for this project. There isn't any code up there yet as I don't have the propeller to validate that I'm even headed in the right direction. If I don't get the propeller in time I may have to put up some known good test code until I can get it all started in the right direction.
Only thing left to do is to create the video introduction.... Yeah... Not looking forward to doing that, I hate making videos. Will be the last thing I do this week, that much I can almost guarntee.
08/06/2014 at 03:40 •
The screen came in today and I have to say that I made the right decision on shape and size! The packaging could have been a bit better (ok a lot better), but it seems to have arrived in tact. Even better news is that on first inspection the screen is protected via an air gap between the plastic shield over it and the actual LCD. That means that I still have a nice buffer in my budget :)
Here is a shot of the packaging:
And a picture of the display in my hand. Its almost the same size and shape as my Nokia Lumia 925 (I'll post a picture of the two side by side some time soon):
Sorry for the strange angle, only way I could get the reflection out of the picture.
After I test it out tomorrow to make sure everything is working I'll tear it down and post some more details. Still have to do that frigging video though :( Any ideas?
08/04/2014 at 18:27 •
After a LOT of research and playing around with the micros and ARM's I have on hand I came to a major conclusion.... They all pretty much suck for doing Component Video out and still having enough space to handle the Capacitive Touch, Sound, battery management, etc... that I have planned for this project.
For that reason alone I'm going to give the Parallax Propeller a try for this project. The price of the DIP version is just $8 (easy to keep in my budget), Composite Video is built in (as well as many other video types), Capacitive Touch should be easy to implement (There is an Object for that), and (most importantly) I've never used the Propeller before.
So, with that in mind here is my revised approach to the project:
- A cog for doing video
- A cog for touch
- A cog for sound
- A cog for the SD Card that will hold the actual programming
- Utilize Catalyst to bring it all together
- Utilize an existing scripting language for programming (probably Lua or Basic since they are built in to Catalyst)
What that means is that so far I've allocated $15 to the display and $8 to the processor for a total of $23 out of pocket for the hardware/compute side of things. Other parts that need to be taken into consideration of the remaining $7 are; an SD Card for programs, the Case, display overlay (protection), the "Touch Panel", sound system, and a few other odds and ends...
That's a lot to fit in $7. Let's just hope that when the display arrives tomorrow there are some good parts that I can cabbage out of it to make this project a success on budget.
08/01/2014 at 15:46 •
Took a bit of time this morning to flush out a few more details in my mind about how I want baby phone to function.
There are already several examples in the wild of creating capacative touch switches utilizing normal BCB's with large areas of copper available to sense when they are being touched or when a touch is near them. For this reason I'm planning on placing a backplane behind the display with 8-16 segments built in that can be used to sense little fingers and toes being mashed on the display. This should give a close approximation of where the device is being touched and thus interactions with the screen should be viable.
I'm also starting to think about the UI and how it should work/react. Across the top of the screen will be a small bar displaying the battery life. This will change from black to white (or some other color combination) and be displayed as a very basic progress bar. All black and the battery is pretty much dead, all white and its fully charged.
The home screen will have a few buttons on it. One that will flash colors, one to play sounds (maybe, if I can fit it into the design), maybe a paint mode, show animal pictures, show letters/numbers, etc... are all different ideas for "apps" I have thought of. Will allow for these home screen apps to be customized a bit. Though details still unclear as to how.
More to come as I work through things.
07/29/2014 at 02:36 •
Today I did some searching around the web for different parts and comparing different phones and cases. Did some baby testing with the phones and cases I have lying around and I think I like the one for my Lumia 925 best. The size is just about right for grabbing and holding. It seems to have a nice tooth to it too (at least according to test subjects :)).
Looking at sourcing 3.5-4.5" TFT LCD's and after some testing with different materials for screen protection I'm thinking of using 2-3 layers of thiner lexan to provide flexibility and durability.
One item that really caught my eye as a starting point is this 3.5" TFT display on Amazon for $15 US (http://www.amazon.com/3-5-Inch-TFT-Monitor-Automobile/dp/B0045IIZKU/). Price is right and the form factor fits in what I'm looking for. Would have to (obviously) remove everything but the screen and driver components, but I'm sure that won't be too difficult.
Since it already has video in might even be able to easily drive it with a small ARM package.
Also decided that my budget "goal" is <$30 for the prototype. Figure if I can hit that with off the shelf components then it is easily in reach of the average hacker.
Really need to figure out how to post pictures after creating my project. Anyone have hints on that?