Dear Rony,
Here are my 2 cents. :-)
On 9/5/06, Rony ronbillypop@yahoo.co.uk wrote:
Central server makes use of a computer and needs underground wiring or expensive wireless network. Plus a power consumption of over 300 watts. Local tiny broadcaster circuits are cost effective and maintainence free. Install and forget. The choice is now FM or WLAN or Bluetooth as per Dinesh's suggestion.
To start with, use simple device which can be further expanded/enhanced. I we start with FM/Analog signals, we will be limiting ourselves in transmitting very specific info. However, if the data transmitted is in digital form, it can be easily manipulated at the receiving end. Also think of multitude of languages in India and around the world.
The initial Blutooth transmitter can be very simple programmable device which stores the location/direction info in the digital form.
The actual use and interpretation/translation of the data can be done in the user hand held device. The device can be used not only by only visually challenged but people who are new to city/town and those who can not read/understand local language including tourists and travelers.
Why are we looking at solar panels and batteries? Like street lights, these could be powered by the municipal electricity or traffic signal posts. Maybe a battery backup for power breakdowns.
The solar panel should be used to make the system self sufficient and make it maintenance free as much as possible.
We also need to check out power consumptions of all the 3 devices mentioned above for a TX. range of 5 feet only, not 100 feet.
I have no exact figures for Blutooth power consumption. May be Terrence can throw some light on this. The range for Blutooth is 5-50 meters by design.
What about a cheap laser diode pumping high density packets into a receiver. The rail has a hollow docking port to simply place the receiver's probe into it for a few seconds, so no shake problem. A beep will tell the user that data is transferred. This will make it cheap and will also function as the user position aligner.
Any thing like this can be made useless in no time at any public place. Wireless data/signal exchange is the only viable option in public places.
Regards,
With regards,