I'd like to take some time to reflect on what I encountered with this project. I will start with the Trinket Pro side of things then move on to Android.
Hardware (Trinket Pro and components)
- Awesome little controller. I will gladly use 2 pins for a USB bootloader. I look forward to using this in further projects
- I wish the bootloader didn't wait as long to start the FW or if the bootloader would only start on hardware reset
- Awesome resolution
- Can require a bunch of RAM (depending on the Library)
- functions can be stripped to gain back ram
- Would opt for a bigger (same resolution) next time 1.3 inch or so
- Very nice not to have to do in code.
- Bulky hardware
- Timing sensitive (but can be fixed)
- Awesome to have all of this built in.
- A bit expensive to buy all of the breakout boards
- Plan on making an all in one at a later date
- I Love this little module. A bit overkill. yes. but easy to work with
- Replaceable for a 4 pin UART based module (3.3v)
- I always underestimate how long hardware takes me. It took a good few days to get everything in the Altoids tin and working.
Software - Android
Android is a lot more time consuming than I remember. I always run it to odd issues. My saving grace for this project when it comes to android is that I was able to reuse the BluetoothSerialService (slightly modified). I remember this taking days to get right. There are still a ton of things I want to learn about android application development and the resources are out there. Hopefully I will have more time in the future to look into this more.
I want to make the device more state-ful with various additional menus and a bunch of additional functionality. This has been a fun learning exercise. I was able to cram quite a bit into the Trinket Pro firmware and still have a lot of ram (despite the OLED Libs) and code store space left.
I would also like to make a PCB for inside of the altoids tin to make it look better. I may do this as a Rev 2. It sounds like a fun design project. I would integrated the Trinket Pro ref design and the lipo management and a handful of other components on the same board. Would free up space in the tin.. Say to carry headphones or something.