I have an application where I would need to generate a "radio trigger" pulse in order to sample adc data collected syncrocronously, in a geophisical application.
I should be able to cover 1 mile between the transmitter and receiver, and the maximum tolerated delay between gnerating the pulse and receiving it it would be 100 microsecs.
Such delay should be as constant as possible, as well. Range is a question of RF power and good antennas, but has anyone an idea of the best TI solution/device in order to solve such problem?
Previously I have been using CC1000 with success to transfer data between 2 devices, but I have no idea of the time delay it could introduce between sending and receiving such signal. Thank you for the support.
Design strategy is important here.
1 mile is certainly possible with the correct choice of antennas, and possibly off-chip LNAs and PAs etc.
Expecting some response from any radio in 100us is a tall order, especially RSSI indications etc.
A better strategy is to establish the link and then encode a trigger on it after the link has been established.
Since you know it takes 35ms for the CC1000 to retune after power-up, you will need to establish the link first.
After the link is established you could modulate it with a codeword which can be decoded by a uC and provide the trigger.
But there are also latencies involved:
1. sending the codeword into the CC1000
2. the CC1000 transmitter to encode the codeword and send it out
3. propagation delay (insignificant here)
4. the remote CC1000 receiver to receive the codeword
5. the remote receiver to send it to a uC
6. the remote uC to decode the codeword and trigger an ADC to sample.
At a CC1000 data rate of 76.8kbps (on a good day), there goes 13us for just one bit time.
No Gian, I don't think syncing to 100us is possible with such a simple radio system.