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ryanrightmer / lis3mdl

A platform agnostic driver to interface with the LIS3MDL (3-axis magnetic sensor)
Apache License 2.0
3 stars 6 forks source link

Takes full ownership of the I2C port not allowing for multiple devices on a single channel #4

Open justacec opened 2 years ago

justacec commented 2 years ago

I have a situation where I need to daisy chain three different sensors on the same I2C channel. With the pattern in this codebase, the driver takes ownership of the I2C device not allowing it to be shared with other device drivers.

I would recommend adding in some way that the driver accepts does not always own the I2C and can be managed by a higher level interface. An example would be to move the i2c device in the struct to be an Option<I2C> and then put in a take_i2c(&mut self) and a set_i2c(&mut self, i2c: I2C) style methods.

An alternative I have seen with other drivers, is to just pass the I2C device to each call. Sounds cumbersome, but might be proffered based on the time it takes to do the extra function calls and cross-checks postulated above.

Thoughts?

quentinmit commented 2 years ago

I believe the intended pattern in embedded-hal is that you should use the shared-bus crate to construct an I2cProxy to pass to each device driver.