project im working on trying to find the best way to do it

[Jeff_5_7]

ok well first im new to all of this but im working on somthing that i need help with. I need to find out how to transmit a signal wirelessly. OK so i will have a circuit with a temperature sensor and a pressure switch i need it to where when the temperature sensor reads between 97 and 103 degrees and the pressure switch is active it sends a signal wirelessly to a reader. I hope that makes sense its kind of confusing for me. all this is going in a small space but the singal only needs to go about 4 feet i was thinking about RFID but i dont know if it would work. Mabey bluetooth???? help me please

 

[dknguyen]

All you need to send it a TRUE/FALSE signal for whether or not the temperature is between 97 degrees and 103 degrees? ANd a second ACTIVE/INACTIVE signal for the pressure sensor?

Nothing else? I would think IR would be your best bet. Bluetooth, and serial RF, and even RFID seem to be overkill and overcomplicated for something that is only sending two TRUE/FALSE signals. But after IR, RFID may be your best choice if you can find one that can operate at 4feet and allow you to manipulate the data being sent (RFID tends to be used with tags with static data rather than sending variable information and active RFID has ranges of hundreds of feet which is overkill, but passive RFID might not be able to reach 4 feet).

 

[albad]

bluetooth modules can be bought for many different required distances, im sure it would be cheaper to buy a short range one like you need.

how are you planning on controlling all of this, like knowing that it is this signal that will trigger whatever you need, and not someone with a mobile phone?

PIC microcontrollers allow programming of modules and some have bluetooth peripherals available for them ready built, just need to plug in and program them

hope this helps

 

[Jeff_5_7]

yea im going to be putting all this in a helmet like a football helmet and so i need it to be kinda small. The pressure switch is active from your head hitting it showing the person wearing the helmet. The temp sensors will sense the temp of the persons head and if its between 97 and 103 it is says ok and if the temp sensor says ok and the pressure sensor is active then i need to transmit a Ok signal so how can i do this and what can i use for a temp and pressue switch that i can put in a helmet?

 

[albad]

for the temperature, there are plenty of options, google thermistor.

some of the most simple are voltage-varying, whereby they output a different voltage dependent on their temperature.

whatever you end up doing, you will need a battery and a controller (chip) either within the helmet, or maybe hidden within some body padding with a small wire running up your neck?

i think you will have to do some programming regardless to get the system working, so some sort of development board will be needed. once its programmed though you can remove the chip to put it in a smaller package

 

[Jeff_5_7]

yea i saw the thermistors but i real question is how can i transmit the signal wirelessly?? and what kind of chip i havnt ever done anything like this so... but thanks for all your help already

 

[albad]

no worries.
ive just started on a chip controlled project myself, and was advised to look at products by a company called microchip. take a look at their site, im pretty sure they do a bluetooth module too.

good luck