Over the past week I have been working with 'bring-up' of the various hardware components. My biggest fear for this project was running our of memory (RAM) due to the Adafruit OLED + GFX Library taking over 1K of RAM (on a 2K Ram MCU) for a display buffer. Don't get me wrong: I absolutely love the work Adafruit has done with the library and what they offer in terms of support on their forums. The library is fantastic for actually drawing to the screen. The first rev of this project is (for the most part) text only. I was able to find a text only library for the SSD1306 (link). This library reduced RAM usage and I (at the time of only testing the oled) was well under 100 Bytes of RAM usage including some basic structures in the sketch. This was a huge improvement when the other library used over 1K (1024 Bytes). I now feel more comfortable that I will be able to included all of the features I want on this device. I am still leaving the button de-bouncing up to the MC14490P to save some code store and RAM. I should easily be able to fit this dip package into the Altoids Tin. I did a mock fitting prior to rewiring the prototype (indicated in my last project log).
At the time of writing this project log, I have a test firmware that tests the oled, various oled supporting functions, and button input. I have stated working on the command structure to interface to the Android Application but it has be a time scarce week. I still need to account for the AT messages from the RN42.