Electronic – CS4270 doesn’t respond to I2C commands

Although you say your comms are properly terminated before insertion or removal, it may be worth trying this solution, as there is a situation where the I2C bus can give problems after a reset of just one of the devices on the bus.

Before initialising the Master I2C hardware, set SDA as an input and test for SDA low.

If it is low then set the SCL pin high.

Then toggle the SCL pin low and high until SDA goes high (i.e. clock out any remaining bits that peripherals might still be trying to send). This cannot take more than 8 clock cycles - if it does then there is some other issue.

I can't guarantee this will solve your problem, but it did solve mine !.

It seems the problem you have is that you want to connect 10 devices to a IIC bus, but these devices can only be configured to one of two addresses. I'm ignoring your proposed solution because the description is too confusing and too long.

One way to deal with this is if each of the devices has a enable line. You can configure the devices into two groups of 5, one address for each group. You then have to have 5 separate enable lines, with only one device from each group being enabled at a time. One way to generate the enable lines is with a 3 to 8 line decoder. Or you can use up to 5 I/O lines for a data bus and another as a clock, then run those into a octal flip-flop. There are various tradeoffs between pins of the micro used and external hardware.

Another possibility is to actively control the address bit of each device. Keep them all at one address except the device you want to use. That device is switched to the second address, which is the only address you ever send over the IIC bus. This effectively uses the address setting line as a enable line. This time you'd need 10 different enable lines one way or the other eventually.