I'd never looked closely at the Decawave stuff before, but the more I do, the more impressed I am (but then I impress easily). The DW1000 chip is about $10 qty 1, if you want to implement your own antenna. The DWM1000 module includes the antenna and associated bits. Either of those would require a microprocessor (their API's are oriented around STM32's). A product based on these would require FCC CFR47 part 15 certification. If this is a one-off application, the TREK1000 evaluation kit includes four ready to use application boards for $990. An application use case for the kit is a tracking system with 3 anchors and 1 roaming tag for 3D trilateration. That kit can be expanded with more evaluation boards. On Wed, Oct 9, 2019 at 10:26 AM Gary Crowell wrote: > "Some sort of comm system.." Silly me. The modules can also pass data, > so as long as the base modules are in range of each other, comms are take= n > care of. > > > On Wed, Oct 9, 2019 at 10:22 AM Gary Crowell > wrote: > >> Sorry, I should have elaborated. These are not GPS, but rather >> module-to-module ranging. Multiple 'base' modules could be placed aroun= d >> the field in the OP's application, and the module roaming in the field >> could be located. Some sort of comm system would need to be implemented >> between the base modules, and whatever processor is doing the location >> calculation. >> >> >> On Wed, Oct 9, 2019 at 10:16 AM Gary Crowell >> wrote: >> >>> Hi, sorry I'm coming into this conversation late, but I have something >>> that may apply. I have no personal experience with these, other than d= oing >>> a PCB layout for one, but an associate has used them with success. The= se >>> are complete RF Time-of-Flight geolocation modules from Decawave. >>> https://www.decawave.com/ >>> >>> These operate in the 3-6GHz range and claim a resolution down to 10cm. >>> The DWM1000 module and an associated processor can be implemented on a >>> 2"x2" board easy. The DWM1000 is available at DigiKey ~$25. They also >>> have development boards and evaluation kits. My friend that has used t= hem >>> has said that the software application utilities were extensive and eas= y to >>> use. They claim ranges of 70 to 250 meters, but I'm sure that is highl= y >>> dependent upon the antennas and other factors. >>> >>> Gary >>> >>> On Tue, Oct 8, 2019 at 7:59 PM RussellMc wrote: >>> >>>> On Wed, 9 Oct 2019 at 02:26, Allen Mulvey wrote: >>>> >>>> > I've never done anything like this but I wonder if you could >>>> > avoid the rotating direction finder and have a non-moving >>>> > solution. Perhaps with a couple of stations along the >>>> > perimeter of the field with two directional antennae >>>> > pointing in somewhat different directions you could >>>> > interpolate the difference in signal strength to get a >>>> > bearing from each? >>>> > >>>> > I mentioned the POSSIBLE use of rotating tx or rx as it adds a degre= e >>>> of >>>> information input not easily available with static solutions. >>>> Rotation could be using phased arry but that seems vanishingly unlikel= y >>>> to >>>> be attractive here. >>>> A mechanical scanner adds time domain (OK, time) variation and a >>>> periodicity to the signal and a signal which has a shaped "lobe" as t= he >>>> tx-rx path aligns and the dealigns once per rotation. >>>> Watching that by eye on eg an oscilloscope would make it very clear in >>>> most >>>> cases which was the real desired path and which the varying spurious >>>> paths. >>>> Analysis 'programmatically is far harder but the cyclical peaks are >>>> liable >>>> to help heaps [tm]. >>>> >>>> >>>> Russell >>>> -- >>>> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >>>> View/change your membership options at >>>> http://mailman.mit.edu/mailman/listinfo/piclist >>>> >>> >>> >>> -- >>> ---------------------------------------------- >>> Gary A. Crowell Sr., P.E. , CID+ >>> >>> Linkedin Elance >>> >>> KE7FIZ Things >>> RocketryCNC >>> >>> >>> >> >> -- >> ---------------------------------------------- >> Gary A. Crowell Sr., P.E. , CID+ >> >> Linkedin Elance >> >> KE7FIZ Things >> RocketryCNC >> >> >> > > -- > ---------------------------------------------- > Gary A. Crowell Sr., P.E. , CID+ > > Linkedin Elance > > KE7FIZ Things > RocketryCNC > > > --=20 ---------------------------------------------- Gary A. Crowell Sr., P.E. , CID+ Linkedin Elance KE7FIZ Things RocketryCNC --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .