This fixes/improves a few issues with I2C support:
* Validate I2C pins, so only pins that are supported by the hardware
can be used (similar to how it's done with PWM).
* Add address to Tx API (without it, the simulator can't really
simulate I2C).
* Add frequency when configuring. Not currently used, but might be
useful in the future and adding it now avoids possibly breaking
changes.
This is a breaking change, but since the simulator doesn't support I2C
yet that seems fine to me. (It does in my local changes, but those need
to be cleaned up before I can push them).
This makes all rp2040 boards available for simulation using
-tags=<board_name>. Importantly, this includes the Gopher Badge which
I'm working on to add to the TinyGo Playground.
Do it all at once in preparation for Go 1.18 support.
To make this commit, I've simply modified the `fmt-check` Makefile
target to rewrite files instead of listing the differences. So this is a
fully mechanical change, it should not have introduced any errors.
This commit changes the I2C declarations so that the objects are
instantiated in each chip file (e.g. machine_atsamd21e18.go) and used to
define I2C0 (and similar) in the board file (e.g. board_qtpy.go). This
should make it easier to define new board files, and reduces the need
for separate *_baremetal.go files.
I have tested this the following way:
- With the LIS3DH driver example on the Circuit Playground Express and
the PyBadge.
- With the LSM6DS3 driver example on the Arduino Nano 33 IoT.
They both still work fine.