Inspired by jancumps post 1958 Turntable from the Black Forest - 21: Right-Sizing my Plans I decided to plan the last 5 weeks of the challenge and look back on what I've achieved.


Looking Back


The features I've promised are:

  1. No user interaction necessary besides hanging the keys
  2. Make key status available on-line
  3. RGB-LEDs to display status of the absent persons
  4. RESTful / IFTTT  / Tasker (android) interface

Additional, optional features I have proposed:

  1. Record speech messages which get played when the person / respectively the key returns
  2. Detect a specific key ring independent of the hook it was hanged on
  3. Placing "ToDo" lists (on paper) on the board and sending "accepted" messages to listeners


I had no plan how to reach the the goals I've set for the challenge until now. Not that I did not know the value of a good project plan, but I am not as experienced as the other contenders therefore I could not estimate the time I would need. Even the proposal was just a wild guess of what could be possible within 15 weeks.

Currently I am able to detect key rings independently of the hook they where placed on and send out the status to a prototype client which is integrated into tasker. Therefore I've achieved 1, 2,4 and b). This is not to bad. I am currently working on 3 and I am evaluating 2 options:

  • using the Infineon RGB Shield (Product LinkProduct Link) and multiplexing the output to 5 RGB LEDs
  • using WS2812B LEDs

In both cases I have the challenge of receiving an interrupt at the end of a PWM period. I've read the Data sheets of both the Infineon and the AMD processor. In both cases they mention that it should work but I can not find out how. I've already spent the combined spare time of 2 weeks on this problem. The documentation for the SAMA5D4 simply is not made for the hobbyist so I might overlook something obvious for the expert.


Looking Forward


Now it's time to do a top-down project plan. There are 5 weeks left and one important goal to reach along with the necessary project documentation. I guess I need 2 weeks to do the cleanup and do the final presentation for the challenge. That leaves me with 3 weeks to solve the Problem, implement the server on the SAMA5D4 (Product LinkProduct Link). For the later 1 estimate 1 week since it is already partially solved. This leaves me with 2 weeks of experimenting and debugging the code for driving 5 to 8 LEDs. Sounds doable but hopefully I'll find the missing puzzle peace soon.