Audio Out Socket on Pandaboard

There are two audio sockets on the Pandaboard in vertical array. Which is audio out, the upper or lower socket, for testing a pair of speakers?

Upper jack is audio in, lower jack is headphone audio out.

Thanks, Chris, for that. I looked high and low for this information before asking here. The obvious place, the Pandaboard ES System Reference Manual, didn’t make it clear which way round the sockets are, and I was concerned that if I stuck the jackplug in the wrong hole I might damage something. Maybe nothing would happen if you stuck the speakers jackplug in the Audio In hole as there would be nothing to go in? But what would happen if you stuck a microphone jackplug in the Audio Out hole?

Anyway, the Logitech Z200 speakers sound great playing “BachFXVI” with the Maestro application.

the Pandaboard ES System Reference Manual, didn’t make it clear which way round the sockets are

As we approach pantomime season, ‘Oh Yes it did’ on page 38 of 82:

The OMAP4460 Pandaboard ES provides a stacked audio connector, which provides two 3.5mm audio jack connections. The upper jack on this stacked connector (J16A in Figure 13 below), is connected to FM Audio Left and Right inputs of the TWL6040 Audio Companion IC (AFML/AFMR). The lower jack on this stacked connector (J16B in Figure 13 below) is connected to the Headset Right and Left outputs of the TWL6040.

Yes, I found this passage, but must have misunderstood it. It is clear enough.

Can you answer my 2 questions?

I would predict that trying to use a microphone as a loudspeaker would be disliked by the microphone.

However a loudspeaker (if that is all it is) can actually work, albeit poorly, as a microphone. That said, many ‘loudspeakers’ used with computers have their own internal amplifiers. If properly designed, they might just give you hum. But if they leak dc might upset the mic socket.

Thanks for reply. Actually, I did accidentally stick a speakers jackplug in a microphone socket, but nothing happened. I see from the Logitech website that some headsets, i.e. headphones plus microphone, have only one jackplug, e.g., Logitech H111 and H151. Apparently, these work with a socket that is both Audio In and Audio Out, weird or what?

have only one jackplug, e.g., Logitech H111 and H151. Apparently, these work with a socket that is both Audio In and Audio Out, weird or what?

Seems simple enough.
4 contact jack plug:

1. Common
2. Audio In
3. Audio Out (right)
4. Audio Out (left)

Re-arrange numbers to match the user manual listing (if they bother)
Stereo input would be an interesting jack plug, it would look like it was a zebra :)

No no no! The barrel end is the ground. The second ring down is the right output, the third ring down is the left output, and the tip is the audio input.

Anybody who is doing anything else is doing it wrongly.

It’s that way for a specific reason – because it is compatible with regular 3.5mm stereo headphones (that simply don’t have the fourth ring, so no input).

Pretty much every Android/Apple/etc phone and tablet with a 3.5mm audio socket follow this protocol.

Sadly the Pi models with audio/video in a 3.5mm jack appear to use the top ring for video, which makes me wonder if it’s possible to sensibly use headphones or speakers with a 3.5mm plug?
[when I take audio from the Pi, I use the headphone socket on the HDMI decoder]

No no no! The barrel end is the ground. The second ring down is the right output, the third ring down is the left output, and the tip is the audio input.

Anybody who is doing anything else is doing it wrongly.

• I said “Re-arrange numbers to match the user manual listing”
• Numbering from the barrel common is 1

Pretty much every Android/Apple/etc phone and tablet with a 3.5mm audio socket follow this protocol.

After looking at a set of Apple stick in your ears with wires running into one and ending in a 4 ring jack I’m wondering where the microphone is

Two snags with the TRRS layout described above.

1) Only has mono input.

2) TRRS is also used to give ‘balanced’ output to stereo headphones. Now moderately common for high-quality units.

Either way an utterly daft idea IMNSHO. Should have been drowned at birth. But then people shouldn’t be using analogue like this anyway.

Two snags with the TRRS layout described above.
1) Only has mono input.

Have a 5-ring jackplug?

Have a 5-ring jackplug?

5-pin domino DIN¹ – it has that retro feel. (That should sort the oldies from the young things)

¹ OK, that was the serial i/o

I assume this assigment of the TRRS has been adopted for use with the headphones which also have a single mic, and the user might want to hear stereo despite sending mono. So, a simple way to use one plug. But then clashes with other applications. And of course if someone at the other end of a ‘Zoom’ or similar call uses the same approach they’ll be sending mono…