On 26 July 2013 14:01, Anderson Lizardo <anderson.lizardo@xxxxxxxxxxxxx> wrote: > Hi James, > > On Thu, Jul 25, 2013 at 7:42 PM, James Baker <j.baker@xxxxxxxxxxx> wrote: >> As part of my summer placement, I've been introduced to some >> non-connectable Ble tags. These are effectively beacons - advertising >> and transmitting data every 250ms. >> >> Now, this is where I'm less clear: >> I am something of a bluetooth newbie as it were, but I know for sure >> they're transmitting more than just the address and name of the device >> (as displayed in hcidump when running hcitool lescan). I know this >> because the data is picked up on an iPhone app I have lying around. >> >> My question is, how would I read data from a connectionless Ble broadcaster? > > You forgot to mention what you need to do with the data once you get > it at which "level" you want to program to get this data. > > On Linux, you have basically two "levels" to communicate with > Bluetooth devices. At the highest level, you have a D-Bus API > (documented on doc/*-api.txt files on the BlueZ source code) that > usually is the easiest way to get information from devices, because > you don't have to worry about packet details. The Broadaster/Observer > API you found works at this level, but as you noticed, it has not > evolved yet to go upstream. It's not being actively developed at the > moment. > > The second, lower level is to program using Bluetooth sockets. At this > level you talk directly to the kernel and BlueZ is not involved. It's > much like programming for TCP sockets, if you have some experience > with socket programming on Linux it will not be much different. > hcitool works at this level. > > You already mentioned that with hcidump + hcitool lescan you were able > to see the data you need to access. hcidump is just a "sniffer" that > shows all the incoming/outgoing communication going through the > bluetooth adapter. My advice is to take a look at the hcitool source > code (tools/hcitool.c) and try to understand how lescan is > implemented. With some effort, you will be able to modify hcitool to > print the information you need. > Hi, thank you, Just to give an update, I have done exactly that - I've gutted hcitool in order to give me the individual packets, which I'm now decoding on the fly. Now just to deal with connectable devices! All best, James -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
