USB FM RDS Solution with sofware - Page 20

84RegalRider · 05-23-2007, 03:48 AM

Mine lags.
went to the drive in tonight and it had about a 2 second lag on it so it kinda sucked.
haha

anyway i have it plugged in a usb 1.1 hub think that could be the problem??
that usb2 would make it go fast enough or think it is with the radio itself and takes a while to decode.

thanks if you got any ideas

Iceman_jkh · 05-23-2007, 04:06 AM

The way the device processes audio means that there will always be a lag.

-Receive the FM
-Encode to Audio
-Send audio to PC
-PC plays audio

Its not very important for normal radio, but I never thought about the drive in scenario

.. bummer.

Sal R. · 05-23-2007, 10:06 AM

Quote: Originally Posted by Iceman_jkh

The way the device processes audio means that there will always be a lag.

-Receive the FM
-Encode to Audio
-Send audio to PC
-PC plays audio

Its not very important for normal radio, but I never thought about the drive in scenario

.. bummer.

Drive in?

Wow...I haven't to those in like...23 years...

lez · 05-23-2007, 10:23 AM

we had one in the uk once, the Asda(walmart) did it as a publicity stunt, big inflatable screen, FM transmission of audio to your car, and a crap film, Grease, of all the crap films to choose...........

84RegalRider · 05-23-2007, 01:51 PM

yea i was pretty sure it would be the radio itself.
haha

80% of the reason for getting it was to still be able to cruse in the drive in. haha
o well

AyrtonSennaD · 05-23-2007, 02:33 PM

Quote: Originally Posted by 84RegalRider

yea i was pretty sure it would be the radio itself.
haha

80% of the reason for getting it was to still be able to cruse in the drive in. haha
o well

my main reason that i purchase this unit was for the drive's in

sucks

lez · 05-23-2007, 02:51 PM

Quote: Originally Posted by AyrtonSennaD

my main reason that i purchase this unit was for the drive's in

sucks

I think most could be improved by a 2 second delay...........

84RegalRider · 05-23-2007, 03:35 PM

yea i never thought about it having a delay.

well anyways it works great, get as good as reception as i did with my alpine headunit, after changing out the stock antnnea.

Just means i gotta work for the ladies now, before it was just go to the drive-in and it was pretty much over.
haha

AyrtonSennaD · 05-23-2007, 04:08 PM

Quote: Originally Posted by lez

I think most could be improved by a 2 second delay...........

how can I improve that 2 second delay ?

Iceman_jkh · 05-23-2007, 06:55 PM

Ask the guys who are doing the .DLL programming to see if they can see a way to reduce the time delay. It is possible the delay is caused by the firmware on the SiLabs chip. If so, its unlikey you can change/fix this. However, if the delay is caused by sync issues/USB issues/Tuning in software, then they might be able to write you a 'lite' version which has no special tuning/signal strength/error checking/RDS features, and reduces the lag to an acceptable amount.

just my 2cents/thoughts.

bimmerpc · 06-01-2007, 03:14 PM

Hi
I got my Silab today from Mouser.com
I read up on all the soldering info I could get from these silab threads. I did buy a 50ohm european motorola standard antenna cable marked "coaxial cable RG58 50 ohm".

When I tried the unit after I had desoldered the factory soldered small antenna the unit works.
When I soldered the coaxial antenna (center lead to the small hole and outer lead to the bigger hole) and plug in the unit again the led light is continously yellow and the unit is not recognized by windows and the program does not pick up any radio signal. When I desoldered the coaxial and plugged in the unit once more without antenna the unit does work again but with ofcourse a bit bad reception.

So... I guess I did something wrong with the soldering.... ?
It seems I did not screw up anything yet since the unit works when the antenna-cable is unsoldered again...

Any help would be extremely helpful

For example; is it important that the two holes including the solder does not connect together between or should they do that?

I mean the distance is like 1 mm so I wouldnt be suprised if electricity goes between the two soldered connections....

OR... Since I am just testing on my home pc and with the cable soldered hanging unconected in the other end, maybe I have to finish my car project and attach it to the car antenna cable to make it work?

grayvader · 06-01-2007, 11:39 PM

you definitely don't want solder connecting the leads together -- make sure there is no contact between the two holes.

bimmerpc · 06-02-2007, 02:06 AM

Quote: Originally Posted by grayvader

you definitely don't want solder connecting the leads together -- make sure there is no contact between the two holes.

Thanks
Looking at the board again, and now when the antenna wire is soldered away there is stil solder left on both holes and they currently are soldered together by just - solder -. BUT the unit works and I can hear some stations briefly. AND when I connect the factory one lead wire the unit picks up better signal even when I just manually press the wire into the hole when the unit is in the computer. When doing this the Silab led flashes red/gren smoothly

But when doing the same with a soldered motorola wire the unit does just light constantly orange and does not work

Definitely something I dont understand here. How can the holes be connected and working without a lead but not working when the lead is actually connected to the holes?

Is it maybe because the small factory fitted antenna is a complete antenna and the motorola (that is just an adapter/wire/extender) is not recognized as an antenna ?

Dont know if it matters but I did cut off the female part of the motorola lead so: Silabs -> Motorola lead -> Male end plug. Not working

((((

Guess I have to consult an electrical shop somewhere.. ...

Bj · 06-02-2007, 04:47 AM

Quote: Originally Posted by bimmerpc

But when doing the same with a soldered motorola wire the unit does just light constantly orange and does not work

Definitely something I dont understand here. How can the holes be connected and working without a lead but not working when the lead is actually connected to the holes?

What will possibly be happening is that you have attached the coax shield to the active part of the antenna, thus shorting out the ground (via the antenna shield) to the USB 5V+ when soldering the tail in. Use a smaller diameter coax to do the tail like I did in the picture.

Otherwise make sure you use a capacitor to couple the antenna if you have a powered (amplified) car antenna and prevent the earth loop problem on the usb radio. Use something like a 47pf ceramic cap between the antenna hole on the PCB and the centre of your coax. Leave the coax shield attached the the ground pad of the board.

bimmerpc · 06-02-2007, 06:19 AM

Ok
I will go and let some expert look at it and maybe buy some extra addons for the short-prevention

I add some pics here. What I am suspicious about is maybe the backside.. but I dont know what I shoule use to isolate the mess between the holes.... permanent marker pen? Ideas? It was some years since I went to basic electrial skills lessons :O)