The VID (Vehicle Information Device) application is now simply a PIC based C program that is installed on a general purpose micro controller card. IN fact, the VID application can now be used in several ways depending on the needs of the user. One way is to use the RF features of the boards would be to divide the application between a sender and reciever/display board. The sender card is powered by the vehicle's 12 volt system. It connects directly to the vehicle's fuel injection and speed measurement system While the receiver card is battery powered--allowing the user to place it any in the passenger compartment in a position that is most convenient. While both sender and receiver cards are electrically identical to the other--- the embedded software on this card performs high level functions required to process data coming from the other card via IEEE 802.15.4 radio system. This board interacts between the user and the sender card----sending the user requested information to a LED display mounted near the user. Via the switches mounted on reciever card, the user can request information on the engine economy functions, the electrical system output, and the temperature of both inside and outside of the passenger compartment-- as well as have access to a very precise real time clock mounted on either the sender or receiver card. Given the open design concept of this device--- new devices can be added interface with any foreseeable future need.For example, vehicle handling dynamics can be monitored via accelerators, vehicle position can be computed via GPS add-on devices. This is made possible by a I2c inteface provide on both cards.
The final configuration is really just a matter of what software is installed on the boards(or board). For instance--- if a potential user only wanted one board---but also wanted to be able to receive vehicle information via his PC--- he could opt for bring the Fuel Injector and Vehicle Speed Sensor information into the sender board as before. Expect, that instead of broadcasting the information to the receiver card for display to to the user--he could simply attach the I2C display board to the sender card----and be done with it. The unit would also come with a USB attachment and software for the user's PC. Vehicle information could then be viewed and/or saved to the PC harddisk.
At any rate, this application is but one of many possible applications for RF remote sensing and control type projects.
In fact, the same PIC/RF technology is about to be deployed to create a system of remote controlled thermostats in our home. Since the card was originally designed for the automotive application, it also includes temperature sensing and real-time clock--- it was a natural step to move this device to monitoring and controlling the temperature in each of the (many) rooms in this house. I will get into the technical specifics of this application later-- but in general using these boards will allow us to manage the electrical use during the winter months with the eventual goal of time-sharing KWHs used as alternative heat source to the oil-fired boiler.
With the ability to centrally monitor and up to 10 thermostats distributed throughout the house, the temperature in those areas(zones) can now be optimized for the exact use required--according to the time of day, and the number of people occupying that space. Assuming that the R value factors are in order---- it is now possible to install by each zone, a single 120 vac, 1500 watt electrical heater for use as supplemental heating.
The astute reader would immediately question exactly how potentially 15000 watts of load attached to 120 volt circuits would be useful when having more than one unit on at a given time would likely trip the 15 amp breakers. And so that is the point--- by finding a proper balance point between heater on time (for each zone) and the requested room temperature-----and the heat loss characteristics of this house. it may be possible to keep a large (and largely unoccupied) house such as this from freezing using a round-robin approach to the several 1500 watt heaters--without (immediately) resorting to the use of a 2.5+ gallon/hour oil fired boiler. (I might add-- that we have a 75 KBTU wood stove that is used to handle most of the living space heat requirements during the waking hours.)
In other words, the basic goal is to keep the huge oil fired boiler OFF for as long as possible during the coldest NE nights of the winter. Of course the boiler also constitutes a heating zone of control--the PIC based system can also trigger it into operation when the temperature finally drops below a point where the heaters are not adequate.. However, having a system that would automatically adjust all zones for real-time conditions---just barely keep the unoccupied rooms in this house from freezing without the boiler would save the large cost of developing a head of steam for no particular reason other then to keep pipes from freezing in the outlaying areas of the house.. Of course depending on the load on each 15 amp circuit some heaters on different circuits could be triggered on together--but the general goal is to run each heater for just long enough to satisfy a constantly variable set point and then move on to the next---until the cycle is repeated---perhaps each hour.
So---with a RF networked group of remote sensor/thermostats (each controlling one heater), the hour-by-hour requirements of each zone can be managed from a central-led PC running Windows XP. In addition , each zone station can be set either remotely or at the station to maintain a specific temperature if it receives no countervailing commands from the central thermostate program.
Ok--- I have said enough for now... just in case anyone is reading this-- drop back soon for more details on these cards and the general progress of things.
