I’m trying to make a cell phone antiloss device utilizing Bluetooth. Its just for fun but its a start into the world of Bluetooth for me. For now, I’d like to avoid using a micro if at all possible.
I’m trying to maintain a connection to a phone via bluetooth. I’m using rn-41sm. I can connect to the module with Hyperterminal and a Bluetooth adapter and it will sustain the connection itself without any data being sent. I’m trying to do the same thing with a Blackberry. The phone pairs to the module without any issues but there doesn’t seem to be a sustained connection. I think it is paired but not connected. Do I have to continuously send data through the connection to keep it alive? Is there a way to do this without using a micro? I do not have anything connected to the module for now either than power.
1 - how much throughput are you expecting on this com link
2 - what types of connection medium other than bluetooth are you expecting to utilize
3 - what exactly is your target purpose for the devices performance,(without divulging intellectual properties that need to be kept hidden for whatever purpose) and can it be thinned down and still work.
Example- keep reducing load requirements until you start to cut into functionality, then step back a notch or two and settle on that hardware set.
4 - related to #3 , do you want to waste a lot of money to make things easier for you (because that is what happens) or
is this bordering criticality of finances and its prudent to focus on getting this done on the cheap. (usually = more manual intensive thinking)
With these variables laid out, a widely varying set of possible directions and decisions presents itself…offering the only tangible window of opportunity to determine / influence if this job will be easy and fast, or painful and punishing.
(I usually stress this step… need to define the scope and then pair it down depending on market cheap-o dynamics.)
1 - how much throughput are you expecting on this com link
–>Don’t really care. All I need to do is notice when the link is down when the distance is too great
2 - what types of connection medium other than bluetooth are you expecting to utilize
–>Only Bluetooth for now. I like bluetooth because most phones have it built in already so I don’t need to add anything to the phone.
3 - what exactly is your target purpose for the devices performance,(without divulging intellectual properties that need to be kept hidden for whatever purpose) and can it be thinned down and still work.
Example- keep reducing load requirements until you start to cut into functionality, then step back a notch or two and settle on that hardware set.
–>Basically when the phone is out of range of the device, the device will signal the user that the bluetooth link has been broken. The RN-41 has a GPIO pin that provides connection status. I’m planning to utilize this pin. I want a bare bones system. Simple is better for now. I would prefer to not have to use a micro if possible. Again, just trying to keep it simple.
4 - related to #3 , do you want to waste a lot of money to make things easier for you (because that is what happens) or
is this bordering criticality of finances and its prudent to focus on getting this done on the cheap. (usually = more manual intensive thinking)
–>Finances are not too critical right now. I can buy this device for under $20. I’m doing it more as a learning experience. Since I already have the RN-41, I’d like to use it and not have to buy something else.
Question: Regarding the RN-41, does anyone know or can confirm that the GPIO output is only 1uA? Seems really little. The suggested circuit shows a 220 ohm current limiting resistor and an LED being driven by this. This doesn’t seem possible.