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KLC Document audio connector pin mapping decission. #364

Open poeschlr opened 5 years ago

poeschlr commented 5 years ago

@evanshultz as you worked out the current naming, could you provide a first draft as a comment?

evanshultz commented 5 years ago

Sure. It seems to fit into KLC clauses S3.7 and F2.4, and should work with all other text since I've included a note about the pin 1 equivalent for footprints below. If that isn't accepted, I note pin 1 discussed in clauses F4.1, F5.1, F5.2, and F7.2.

I've written this explicitly for audio jacks and nothing else. This could be condensed and generalized if we apply this to other places. For example, I believe there is acceptance for SD/SIM/etc. cards at . If this is the case, I can re-word to a general statement that in some places we use names instead of numbers for pins and then perhaps a small table showing the types of symbols/footprints were this is done.

I think an image is very helpful and we can find a nice one at [1], but if we need to make our own let me know. Alternatively, I have pointed out several symbols which illustrate this.

For S3.7:

Audio jacks have specific pin names which are industry-standard and broadly understood. By giving the symbols pin names, rather than numbers, a single generic symbol can be used for a variety of footprints without needing many manufacturer-specific symbols.

The basic pin names are "T" (tip), "R" (ring), and "S" (sleeve). "R" is used for stereo or balanced systems and is not always present. See AudioJack3 for a TRS symbol.

Multiple ring connections may be used, and in that case they are named "R#" where "#" is a number starting at 1, with "R1" closest to "T". See AudioJack5 for a symbol with three ring terminals.

Some pins may be "normalled" (or switched) meaning signal flows through the connector when no jack is inserted, and the signal path is broken and re-directed from the jack when it is inserted. The normalled pins are given a suffix "N" after the name of the pin they switch. AudioJack5_Switch shows the "T", "R", and "S" pins being switched. AudioJack_SwitchTR is another example where "S" is not switched.

Note that XLR connectors have standard pin names of 1, 2, and 3. Combination jacks will when use both letters and numbers. An example of this symbol is XLR3_AudioJack3_Combo.

For F2.4:

Audio jack footprints use pins "T", "R", and "S" in lieu of numbers to match with the schematic symbols. There are other pin name variations for more complicated pin configurations. The component datasheet will need to be scrutinized and then pin designators matched up with the correct pin names before submitting a new audio jack footprint.

1: https://www.cui.com/image/getimage/9169?typecode=m

poeschlr commented 5 years ago

The image uses pin numbers which wouldl be confusing. I suggest making a similar one but instead of 1,2,3 use T,R,S

Edit: i am not so sure that f2.4 and s3.7 are the correct rules to edit.

On the footprint side we might want to add a rule similar to "by default footprints use the pin numbers indicated in the datasheet" and then list exceptions. (audio connectors, sd cards, ...) I would add it somewhere under F4 (would be best added as 4.3 but that would require moving all other rules.)

Or we add these rules to the general section

evanshultz commented 5 years ago

Here is a version of the image with the signals changed from numbers to letters. I believe it should be OK for us to use this in KLC but we should provide attribution. trs_plug_jack

My skills in this area are weak so if we need to make something from scratch we should probably enlist from professional help.

If you want to put the content in other places, go for it.