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04-13-2016 10:01 AM
i am a DAB developer in using Si4684. i design the new platform using EFM32 CPU.
the reception is very good, nearly -100dbm for for channels . but only one problem is not solved!!
we send a few sample (product) to customer in German, they said the reception is good but only
12 Service Channel is found in my sample. For the others ,Frontiee or Q8, they can get 52 Service
Initially, i suspect the internal RAM is not enough to hold Service Information , so i change to use HG and
reserve more buffer for SI , Buffer size is 3K and the Stack size is 1.5K.
But the second samples still have the same problem .
I need someone who is familiar with DAB or source code to help me.
Thanks for your attention.
04-13-2016 03:03 PM
The command GET_DIGITAL_SERVICE_LIST can return max. 2047 Bytes of payload. So buffer of 3kBytes should be enough.
In AN649 it says: "A max of 2047 bytes of service information."
Anyway, none of the ensembles known to me here in Germany has 52 services in it. So I assume the 52 services reported by your customer is the total count of all services of all receivable ensembles.
Can you please clarify, if all expected ensembles ("channels") can be received and acquired during channel scan?
And please also check, which services are missing.
04-13-2016 06:33 PM
thanks to reply, let me explain in detail .
i would like to define :
1. physical channels ( 41 channels in DAB ) called : DAB station
2. Service Channel (SC) in Ensemble (form single DAB station) : service channel
3. All SC in all DAB station : total service channels.
the first thing i am not sure is the meaning of "52 channels " reported from customer.
the customer did not explain to much , so i think it is total service channels.
in my platform, s/w will keep on scanning until to the last station , totally 41DAB stations .
i did many tests in your ShenZhen office using two DAB generator to simulate multiple DAB station.
it is ok.
i also test with a ETI file with 32 Service Channel .
it is also ok.
but the customer report it still can not get all service channel .
the original platform provided by Silabs is using 8051 , only 4K RAM and less than 1K buffer for SI.
is there any complaints from customer to this problem ?
do u know how many DAB stations in German ?
do u have ETI file has 52 for testing
04-14-2016 02:12 AM
The number of receivable DAB services in Germany depends on the location.
In order to better understand the problem reported by your customer, please ask him to provide:
- A list of all services receivable with the other receiver
- A list of missing services with your receiver
Maybe you have to provide them with some means to get debug logs from your software in order to track down the problem's root-cause.
04-14-2016 01:53 PM
are u working in DAB ?
Can you at least ask them to do a channel scan for each single channel on which they expect to reiceive something and report the channels and found services per channel back to you?
I've written two DAB-related applications (for Windows), one for Realtek RTL2832 and the second one for Silabs Si468x, so I have some experience in the field of DAB.