I have added a DS3231 RTC to my Industruino Ind I/O 1286. I connect the RTC using the expansion port pins D2,D3, GND, and 5V. I'm using the DS1307 library. This works fine when I just use the USB port to power the Industruino, but when I power using the 24V the RTC does not work and the 4-20mA channels do not work. This appears to be an I2C address conflict. The I2c address of the DS3231 RTC is set at 0x68 which is also the I2C address of the Industruino's A/D converter chip. From Indio.cpp:
// I2C address for MCP3422 - base address for MCP3424
#define MCP3422_ADDRESS 0X68
There is no way to change the RTC chip I2C address. From the MCP3424 spec sheet, http://ww1.microchip.com/downloads/en/DeviceDoc/22088c.pdf, pins 9 and 10 allow changes to the I2C address. How can I change the address using these pins?
Another option is to use a DS3234 RTC board which uses SPI, like this board http://www.icstation.com/ds3234-real-time-clock-deadon-ds3234-breakout-compatible-p-5160.html.
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