hw i2c & sensor module about lua-rtos-esp32

[jolivepetrus]

Hi loboris,

We will create a new branch for give support to i2c in Lua RTOS. I took a look at your proposal for i2c driver and I have some comments about it:

• Lua platform folder will be disappear in the future

• Drivers in Lua RTOS are intended to have all the intelligence for allow simple Lua modules, and in the future for other programming languages.

• Drivers lock those resources they need via driver_lock function. For example, if a driver need 2 pins that pins are lock by the driver. If later, if another driver lock resource locked previously by another driver an error is raised.

• Lua modules take care about errors raised by drivers and an exeption is generated to the user if a driver error is raised. Lock resources are important for us because they avoid programming errors from the blockly environment.

The ADC driver is a good example for know more about this.

[loboris]

Thanks for your comments, especially about driver_lock function, I've somehow missed it.

[jolivepetrus]

You have i2c driver and i2c Lua module in master branch see commit bb446ad
.
We have to write the wiki for this module, but you have an example in (https://github.com/whitecatboard/Lua-RTOS-ESP32/blob/master/components/spiffs_image/image/examples/lua/i2c.lua).

For sensors we are thinking about a more elaborate strategy that fits better with our educational perpectives. Some ideas about that:

• Sensors are things that use drivers, so it would be better to put them in another folder

• Is possible to have a Lua module that encapsulates generic sensor behavior, such as filters for reduce noise, ...

• We are think in something like:

  instance1 = sensor. BME280(i2c.I2C0, address, speed, sda, scl)
  instance1:read()
  ...

  instance2 = sensor.TMP36(adc.ADC0, adc.ADC_CH6)
  instance2:read()
  ...