MicroPython's I2C and SPI support

[liudr]

Thanks Roberthh. I will go with manufacturer's recommendations.

[Roberthh]

You rtc device may also work with 3.3v. If you have a product link, I could look at it.

[liudr]

Thanks Roberthh. The RTC I have is DS3231, which does work at 3.3V so is the ADS1115 ADC I want to use. But in order to sense 5V analog sensors, ADS1115 needs 5V supply as well so does the PCF8574 GPIO IC for LCD. I have a couple of bidirectional level shifters I can use. I can get level shifters for cheap. I used to design my own boards with surface mount components. Nowadays the breakout boards are cheaper than the components they break out so I'm just designing carrier boards to organize various breakout boards into a coherent design. Here is a data logger I designed based on Arduino:



This is the board:



The logger could use a nice upgrade with ESP8266-based dev boards such as WEMOS mini or NODEMCU.
The LCD has a PCF8574 backpack. Everything fits nicely inside the enclosure. The ADS1115 spot is not populated. There are also multiple options for boost converter and LCD backpack types (supports two that have different pin arrangements) and a spot for MCP23008.