Hi
I am using dw1000 chip for my project with two-way ranging mode. I want to get the data from the Tag input of the device with the sensitivity of 1ms. Moreover, when we give the DW1000 an external SYNC signal, can it transmit the data with reference to this signal by adding time information?
Thanks
Hi,
Appending your IoT data to the TWR is trivial, just change the length of the tx and expected rx payload.
Using sync pin is more delicate subject, you cannot do what you want as sync pin is “just” resetting the internal system timer and it starts counting again immediately starting from sync pin time point. What you can do is to do a delayed TX with fixed delay wrt to sync pin. On The RX side you can measure the RX timestamps period.
Good luck.
It is possible to use the sync pin to initiate a transfer but it does depend on exactly how good you want the synchronisation to be. From the user manual:
6.1.2 One Shot Transmit Synchronisation (OSTS) Mode
DW1000 allows the transmission of a frame at a deterministic time after the SYNC signal is asserted, using the One Shot Transmit Synchronisation (OSTS) mode. OSTS mode provides for the transmission of a frame at a well-defined time relative to the assertion of the SYNC DW1000 input. This time will vary slightly per part, typically 12 ps, but may vary up to 3 ns across process for all parts.
You could use sync to reset the time counter to 0 and then schedule a transmit for a known time but unless all the devices are on the same 38.4 MHz clock that would also be inaccurate since the exact zero point will depend on the phase of that clock.
Also if adding data to the data packets in a TWR then you may need to increase some of the time delays and timeouts from the defaults to allow for the longer packet transmit time. How much depends on how much extra data you are adding.