Use JST port for I2C and add new JST port for I2S/Expander#466
Open
roryjamesallen wants to merge 1 commit intomainfrom
Open
Use JST port for I2C and add new JST port for I2S/Expander#466roryjamesallen wants to merge 1 commit intomainfrom
roryjamesallen wants to merge 1 commit intomainfrom
Conversation
roryjamesallen
added
improvement
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Connectors
I've using the JST-PH connector for both ports to match the STEMMA format (see below) as well as because it's just generally a nice small but strong keyed standard. It's about the same size as a 2.54mm header but with an extra shroud that should prevent people plugging things in the wrong way.
I2C Port
I have seen very few people using the I2C port so I believe the gain from using a JST-PH connector in the same layout as the STEMMA series of I2C expansion boards offered by Adafruit will encourage more people to add functionality to the module in this way. It is unfortunate that the layout I originally chose was not the same as the STEMMA specification, so the SDA and SCL lines have had to be swapped to match.
Hopefully the fact that a new connector is being used (with an incompatible pin pitch) will be enough to prevent anyone from accidentally using the wrong layout, and as the power pins have not moved, there is no increased chance of a serious short or other electrical issue.
I2S Port / General GPIO Expansion
There has also been some experimentation by user 'Visions' and others in the Discord server with external I2S DACs for audio output. This PR adds an extra port which breaks out all the remaining unused GPIOs of the Pico (8, 9, 14, and 15), allowing easy prototyping of expanders such as this, and the groundwork for future official expanders which need their own GPIOs (e.g. for PIO outputs) where the I2C port cannot be used.