dw1000 transmit max power

[justinleeyang]

hi, all:

Can lps node add transmit power ? Currently, the transmit power have adjusted maximum ? I want to add distance without PA.

[arnaud]

Hi Justin,

The current setup is using the default power value I got from the Arduino lib that was used as a base for the DW1000 driver. As far as I know those are the default values from the datasheet and are not the maximum power the dw1000 is capable to output.

We have not tried to play with power yet. Some other things we are going to try to increase the range: increasing the preamble size and lowering the data transmission rate.

[justinleeyang]

hi, arnaud:

I don't adjust preamble size, but I try lower the data transmission rate to 110Kbps, range a time successfully about ~10ms, so long,
so I will try 850Kbps.

[arnaud]

The preamble might be worth a try since it will not increase the transition time so much: it takes 1us per preamble symbol, we currently have 128 symbol. Since we currently have time-slot of 2ms with TDoA I estimate up to 1024 symbol will not cause so much problem with TDoA.

[justinleeyang]

hi,arnaud:

I have already try 1024 preamble size, set the mode as following:
const uint8_t MODE_LONGDATA_FAST_ACCURACY[] = {TRX_RATE_6800KBPS, TX_PULSE_FREQ_64MHZ, TX_PREAMBLE_LEN_1024};
when use 128 preamble, the range time about 2ms, but use 1024 size preamble, range time about 4.8ms. and the range distance
no more.

[arnaud]

Hi Justin, thanks for reporting the result! This is interesting (and surprising) then I guess changing the output power is our best bet to increase range.