ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
I want to control my BeoLink Passive through a self-made IR receiver based on the TSOP7000 (IR receiver for 455kHz). For now I connected PIN 2(GND), PIN 6(+5B) and PIN 7(IR out) of the 7-pin DIN connector with a TSOP7000 - without any effect.
Any ideas on how bring it to work? A detailed description/spec of what the BeoLink passive expects on the 7-pin DIN connector would help as well.
Hi,
try a pull-up resistor from PIN 6 to PIN 7 at the DIN plug. The value for the pull-up could be between 2K2 and 4K7 .
Are you sure you use the right pinout of the TSOP7000?
Hope this helps
Ralph-Marcus
Hi RaMaBo,
thx for the proposal.
I tried the pull-up (2K7) but still does not work.
As of the right pinout: I connected the pins (TSOP/DIN plug): 1/7, 2/2, 3/6
To be absolutely sure, I swapped pin 6 and 7 without success.
Meanwhile I checked positively that the BeoLink Passive still works fine with the B&O IR eye.
Hmm, could be that the B&O puck has active high output and the TSOP gives a active low signal.
You can check this by connecting the puck to the Beolink passive and then measure the voltage at pin 7 of the DIN plug when no remote key is pressed. Should be near 5V, maybe a bit lower. Pushing a key on the remote should lower the voltage => active low. If the voltages are the other way round the puck gives uses active high and you have to invert the signal of the TSOP7000.
Best key used is volume up/down because they repeat the IR signal if pressed longer and gives a bit better reading at the (digital) voltmeter. An oscilloscope makes live easier
Those TSOPs can be damaged quite fast by wrong connection of the output and Vcc This can happen by placing the TSOP wrong. See here for correct pin-out of the TSOP7000
Checking the voltage did not provide a clear answer. Meanwhile checked the puck with an oscilloscope and found it uses active high (5V level). I inverted the TSOP7000's signal with a transistor and it still did not work. Comparing the signals of the puck with my circuit showed that they are looking pretty much the same while a key on the remote is pressed.
But, I found that in "silent" phases the puck generates some kind of signal/pattern which does not really look like noise. That is why measuring the voltage did not bring a clear answer.
I suppose it is kind of a channel encoding.
Any ideas?
I got it working now!
Forget about the channel encoding stuff :-). It *was* noise - maybe coming from the I2C stuff on the B&O IR eye board. That would be an explanation for looking like a regular signal.
The key is to increase the signal duration. While the TSOP7000 provides 200us signal peaks, the BeoLink passive needs about 1500us. I guess this is to make the signal more robust to cope with the fact that a connection between the eye and the B&O device (BeoLink Passive here) can be several meters. I used a NE555 as monostable element followed by a transistor to convert active-high back to active-low.
As a result I am now able to create a B&O IR eye alternative for just a few Euros. This thing should basically work on any B&O device with an IR-IN plug.
Thanks to RaMaBo for supporting.
And thanks for posting the outcome, that's good knowledge!
I believe the key difference here is that the physical Datalink connections use longer pulse widths to overcome cable capacitances, while the IR medium uses very short carrier bursts to both save the battery and allow for higher power transmission even though the encoding is basically the same.
--mika