-
-
Notifications
You must be signed in to change notification settings - Fork 1.1k
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
Feature/wire on request more #550
Open
jwagnerhki
wants to merge
2
commits into
arduino:master
Choose a base branch
from
jwagnerhki:feature/wire-onRequestMore
base: master
Could not load branches
Branch not found: {{ refName }}
Loading
Could not load tags
Nothing to show
Loading
Are you sure you want to change the base?
Some commits from the old base branch may be removed from the timeline,
and old review comments may become outdated.
Open
Conversation
This file contains 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
Memory usage change @ 3dec52e
Click for full report table
Click for full report CSV
|
jwagnerhki
added a commit
to jwagnerhki/cerastar-i2c
that referenced
this pull request
Mar 8, 2024
…stMore() callback to the usual Arduino Wire API
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.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.
Extend the Wire object by an onRequestMore callback. Example code is included.
The pull request extends the existing onRequest callback mechanism in the I2C target mode. The existing onRequest callback provides some data into the transmit buffer. However, that callback is invoked only once at the very start of the I2C transaction. There was no mechanism to top up further data mid-way into a continued transaction.
In more dynamic protocols, the actual number of bytes that the I2C controller is expecting is sometimes not known in advance - the controller tries to clock in as many bytes as it needs, before terminating the transaction. If the onRequest -provided initial data get depleted, the new onRequestMore is invoked and allows the user to top up the transmit buffer. The onRequestMore gets invoked each time the transmit buffer runs empty, as long as the I2C transaction is still active, i.e., until the I2C controller terminates it.
(Note: if these additions are acceptable, it'll probably be necessary to update https://github.com/arduino/ArduinoCore-API/blob/master/api/HardwareI2C.h by adding a corresponding new line with "virtual void onRequestMore(void(*)(void)) = 0;' to it.)