Re: Set Tmin and Tmax for inquiry?

[Carles Cufi <carles.cufi@gmail.com>]

Hi Ilya,

The hcitool application uses the HCI library function hci_send_req()  
to send a periodic inquiry request to the controller. The max and min  
periods are hardcoded to 16 and 10 respectively, and there is no user  
option to change those. In the case of your python script I can't tell  
you for sure because I haven't looked at the code of the python BlueZ  
bindings, but if the API call it presents to you has no Tmin and Tmax  
that means it's hardcoded there too. The bluetoothd (formerly called  
hcid) has absolutely nothing to do with the hcitool since this tool  
bypasses it completely. For python, you should look at the code for  
the bindings and find out how the API implementation handles your call.

--
Carles

On Mar 18, 2009, at 9:42 PM, Ilya Rubtsov wrote:

> Oops. Mistake. Right is: 'max 24 min 16 lap 0x9e8b33 len 8 num  
> 0' (StartDiscovery) and 'max 16 min 10 lap 0x9e8b33 len 8 num  
> 0' (hcitool)
>
> Ilya Rubtsov пишет:
>
>> Hi
>>
>> I'm developing an application for bluecasting. So period of  
>> periodic inquire is important for me.
>> AFAIK, inquire process takes 10.24 seconds (Bluetooth 2.0). But if  
>> I use StartDiscovery method in python script, then I see this in  
>> hcidump:
>>
>> < HCI Command: Periodic Inquiry Mode (0x01|0x0003) plen 9
>>  max 24 min 16 lap 0x9e8b33 len 8 num 0
>>
>> and I get "Inquiry Complete" event every ~24-30 second. But if I  
>> use 'hcitool spinq', then I see:
>>
>> < HCI Command: Periodic Inquiry Mode (0x01|0x0003) plen 9
>>  max 24 min 16 lap 0x9e8b33 len 8 num 0
>>
>> and "Inquiry Complete" event takes place every ~13-15 seconds. And  
>> in both cases all remote devices is being founded, so I don't see  
>> any reason for longer inquiring. AFAIK HCID internally sets Tmin  
>> and Tmax parameters, but is there any way to affect to its  
>> 'decision'?
>>
>> P.S. Excuse me for my English :(
>
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