This topic opens a new series of projects that show you how to build an access control system. The first iteration is simple: Users present their ID cards, and the system unlocks the door for the users whose cards are in the data table.
12 posts tagged with "tibbit_03_1"
View All TagsIn the second Access Control project step, we add the manual exit button. To simplify testing, a keypad key is used in lieu of an actual physical switch wired into your TPS' IO line.
The third step in creating a full-featured access control application adds the door open sensor and an alarm relay. Again, a keypad key is used instead of an actual door sensor wired to your TPS' IO line to simplify testing. The F4 key (marked "DOOR SENSOR" on the LCD) stands for the actual door open sensor.
This project step adds the id_expiry DateTime field to the user_ids table. Once the current date and time are past the expiry date and time for an ID card, it stops working.
This step adds logging of everything that is going on in the access control system.
This final step shows you how to work with real inputs. For simplicity, all previous project iterations implemented the exit button and the door open sensor as keypad buttons. This is convenient for testing, but real life requires wiring a real button and an actual sensor to your TPS. In this project's configuration, external inputs are wired in through Tibbit #00-1 (four direct IO lines).
Having worked through The Basics section of the Tutorial, you now know enough to take on a "real project." We start with a multi-step implementation of a device that is common in agriculture -- the Sprinkler (Watering) Controller. Such controllers turn the plant watering on and off according to a pre-defined schedule.
Hardcoding the watering start times and duration -- as we did in the first version of the application -- is a "quick and dirty" way of creating a Sprinkler Controller for personal use. If you are designing for your customers, a bit more "finesse" will be required to satisfy the general public. Obviously, the proper way is to have an editable schedule table. Each entry in this table would consist of the watering start time and the watering duration.
This project expands on the previous application by adding status messages displayed on the LCD. For this to work, you must have the TPS2L(G2) device -- only this model has the LCD (and keypad).
It is great to have the watering happen on schedule, but sometimes you will want to manually operate the sprinklers, even if to test that the hardware works properly.