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Linux i2cdetect generates nothing on SCLK

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kishores:
Hi guys,
I am trying to interface an IO expander MCP23017 with Nano Pi Neo2 . I am using Friendly ELEC's Ubuntu 16.04 OS .
I am able to enable I2C 0 on the device and can find a device /dev/i2c-0 on the system .

However , I am not able to find the IO expander device at address 0x22 when I run i2cdetect . I have checked the signals on respective SCLK and get absolutely nothing . What options do I have besides changing the OS ?

NiHaoMike:
Do you have pullup resistors on the bus?

kishores:
Yes . Even without the pullups I should be able to get some signal on them , right ?

andersm:
Some boards need to load a device tree overlay, or adjust some other boot parameter to configure the I/O. I think FriendlyElec has a tool called "npi-config" that lets you enable and disable peripherals.

mikerj:

--- Quote from: kishores on August 04, 2019, 04:20:26 pm ---Yes . Even without the pullups I should be able to get some signal on them , right ?

--- End quote ---

No, an I2C bus cannot operate without pull-ups.

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