added read write and init

[dyldonahue]

Changes

Built a drive to handle coms to the gpio exander chip

Notes

Just by way of needing function pointers have common parameters, this structure forces the application to have a wrapper for its i2c reads/writes. For example, using HAL, wed have to have the read/write functions we pass in internally handle i2c_handle. Not sure theres a way around this, just something to note though

Test Cases

Not tested/verified

To Do

IDK if we want to abstract any more APIs, for shepherd i dont see the need

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Closes # (#65)

[nwdepatie]

Feels a bit yucky, look at my comments. I think you're def picking up on the general vibe I said tho for function pointers

[nwdepatie]

Can we make these typedefs to make this less verbose? Or maybe like a macro? This looks yucky and I feel like there's a better solution.

Maybe a good idea is to create typedefs for eeprom_read or eeprom_write and then the user can pass them in? Or maybe if you wanna make it more generic make a typedef for I2C_Read/write or Reg_read/write?

[nwdepatie]

Tested, and approved