Esp32

[tablatronix]

PR is FOR TRACKING and diffs, do not merge!

[tablatronix]

@UnexpectedMaker this PR is just to track the commits and files changed for diffing, please ignore thanks.

[tablatronix]

esp32 support, mosty commenting stuff out

ToDo

removes flashstorage to be abstracted into methods and add ifdef wraps

• esp32 flash storage support for read and write methods
• esp32 tone buzzer
• esp32 relay pwm use sigmandelta or ledc abstract to start and wriite methods

@todo comments added to code
instead of sticking ifdefs all over the code, abstract the few instances into 4-5 methods and handle there

methods needed

• storage init
• storage write
• storage read
• relay init
• relay set
• buzzer ( existing )

not related

• abstract temperature to allow different reading methods, adc, i2c, ads*, non thermocouple etc.
  This controller should be able to control hotplates, kilns etc for example

❗️ I added some temperate test code, and ads1x code for adc modules you might want to remove that if you are using the max chip, I have not received mine yet, i will try to add some defines to swap that behavior back

[tablatronix]

added sigmadelta tests, NOT TESTED
not sure if sd or ledc is best for the relay and buzzer control, I have not worked with either yet

[tablatronix]

I did have to modify spline lib was getting some warnings or errors dont recall

kerinin/arduino-splines@master...tablatronix:master

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pwm refs

esp32 examples

https://github.com/espressif/arduino-esp32/tree/master/libraries/ESP32/examples/AnalogOut

some pwm helper lib

https://github.com/nkolban/esp32-snippets/blob/master/cpp_utils/PWM.cpp
https://github.com/nkolban/esp32-snippets/blob/master/cpp_utils/PWM.h

ifdef wraps

espressif/arduino-esp32#4 (comment)

analogwrite abstraction/polyfill

espressif/arduino-esp32#849

no pwm, use DAC

https://esp-idf.readthedocs.io/en/v2.0/api/peripherals/dac.html