Re: Line In/Out Pinout to Mac

Ben Cook

Thank you Juergen,

I verified all connectors on the board to the TRRS cable look good. So no issues there. Also in case it helps anyone else, the solder points from the previous photo bottom left moving clockwise are: ring 2 (ground), ring 1 (line in), tip (line in), and sleeve (line out).

I did overlook that part of the manual. I was able to adjust the audio in on the Morserino according to the manual. I tested that it can receive and decode morse code when generated by the computer! So, we are narrowing in on the input issue of getting the line out from the Morserino into the MacBook Pro.

Birk mentioned that maybe that Mac doesn’t detect the Morserino as a microphone. I believe that is the issue right now. I measure DC voltage across the TRRS ring 2 (ground) and sleeve (audio out) so I believe the Morserino is outputting audio voltage.

73, Ben

On 28 Aug 2019, at 11:07, Juergen Wagner wrote:

Yes Ben,
i think thats looking gud: TRRS = 4 contacts - and 4 are soldered. The unused may be switched connection points.
You know the automaticly switches off speakers when u pluged in a headphone...

So next what i would test with a OHM-meter: solderd connection points and the TRRS at the cable.

And then there may be an un-read point in the manual (pg 6):

A long press of the RED button starts a function to adjust the audio input level (and possible the output
level on a device you connected to the Morserino-32's line-out port).


Am 28.08.2019 um 17:31 schrieb Ben Cook:

Hi Juergen,

Good point. I connected the audio out to an amplified speaker and heard no audio. Tested with the headphone jack and got plenty of audio. This made me thing there might be something wrong with my soldering job or the component. Sure enough, when I tested, the two pins in the yellow box appear to be connected even when not keying. The solder joints don’t look connected, so I’m wondering if I got a bad component or where to check next. None of the other pins seem connected.

On 28 Aug 2019, at 9:47, Juergen Wagner wrote:

Hello Ben,
in your information i can't see: do u hve checked with earphone / scope or other device
that there is the keyed audio at the sleeve ? My first idea is that there is no audio there !

Am 28.08.2019 um 16:23 schrieb Ben Cook:
Good morning! Trying to figure out why the TRRS pinout from the Morserino to a Mac input doesn't work. Looking at the manual and then looking at the Mac's pinout, it seems like this should work with a straight through TRRS male-male cable. I learned today this appears to be the CTIA standard.

apple pin purpose morseino pin purpose
tip left audio tip line in
ring 1 right audio ring 1 line in
ring 2 ground ring 2 ground
sleeve mic/in sleeve line out

Yet when I plug the Morserino into my mac and go to the CW Keyer, I see no audio coming into the mac. When I go to the iCW function on the Morserino, I see no audio coming into the mac. I'm missing something here, but not sure what if anything to splice in the cable to make this work. Some additional insight appreciated.

Ben, N6ELF

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