There are three potential directions for further project evolution, each of them may exist and develop independently.
External accessories might be plugged in via J2, J4 are CONN1 connectors. List of possible accessories is given below:
CONN1 is normally used with external relay board to control
one or two appliances. For example, a table lamp could be switched on or/and
off when preset time comes or certain event occurs. Currently port output
state might be triggered by incoming SMS
(refer to Chapter 6, Command Set List). As
an example, there is a basic schedule implementation which switches
output 1 on and off every day according to the time defined
RTClock.asm, please see the code fragment below:
Example 9.1. RTClock.asm Settings
.EQU SCHEDULED_OUTPUT1_ON_HOUR = 7 .EQU SCHEDULED_OUTPUT1_ON_MIN = 0 .EQU SCHEDULED_OUTPUT1_OFF_HOUR = 7 .EQU SCHEDULED_OUTPUT1_OFF_MIN = 30
It becomes obvious, that
output 1 state will be set to
active (high) level at 7-00 am and set back to inactive (low) level at 7-30 am
every day. To implement more sophisticated behavior allowing dynamically
change setting for both outputs extra development time must be spent.
It would be a good reason to keep such settings in EEPROM
rather than been hardcoded in a program memory.
J4 connector is normally used for plugging in external temperature sensor, such as DS18S20 by Dallas Semiconductor. Current implementation is capable of detection the amount of thermosensors connected to the bus but fetches data from the first detected sensor only. Temperature data will be incorporated as system field into every HTTP request and will become automatically available as soon as the sensor is connected and recognised. Again, to enhance this capability and to handle more than one sensor, extra development time should be spent.
J2 connector is reserved for future extentions. Its resource might be used for plugging in extra PIR/etc sensors. Currently there is software support for external LED matrix display. The schematics and the PCB of the display will be incorporated in the next UserGuide revision. Also J2 might be used for any other purpose but appropriate software support must be provided as well.