This makes life easier when calling e.g. `saul_reg_write()` with data
stored in flash.
As now the signatures for reading and writing differ (in that `const`
qualifier only), `saul_notsup()` is split into `saul_write_notsup()`
and `saul_read_notsup()`. However, one is implemented as a symbol alias
of the other, so that ROM consumption remains unchanged.
- Use standard RIOT style `ina2xx_params_t` on initialization as explained in
[1] instead of a custom API
- Provided a default configuration via `ina2xx_params_t` as required by [1] that
works fine for the INA219 breakout board and with an optimal resolution that
still covers the whole range of USB high-power devices (500 mA @ 5V) with a
comfortable safe margin.
- Changed initialization procedure to include a device reset and connectivity
test, as required by [1]
- The calibration value is now calculated by the driver
- This simplifies using the driver a lot
- The user can still choose a trade-off between range and resolution that
matches the application requirements, but now among predefined values
- This allows the driver to easily convert the raw data into meaningful
physical data, as the resolution of the raw data is known
- All measurements are provided as meaningful physical data as required by [1]
[1]: https://github.com/RIOT-OS/RIOT/wiki/Guide:-Writing-a-device-driver-in-RIOT
The INA219 has the exact same interface as the INA220 (including values and
semantics of the configuration register). Thus, this driver can be used for
both. The ina220 has been renamed to ina2xx to reflect this and pseudo modules
for the ina220 and ina219 have been added.
