I2C地址格式

Question

I'm working on writing/reading data across i2c to the USB to i2c board UMFT201 . The data sheet says the default i2c address is "22h". I can't figure out what that means. When I use the general call address it seems to be able to write data to the board; so I think my code is working. I'm new to C programming; thus not sure what that "22h" means.

Answer 1

There is a trick to understand about the FTDI UMFT201 and FT201X chip.

It is an I2C slave chip.

Therefore it is not a master, obvioulsy. This means you need a micro-controller to act as the I2C master plugged into into the UMFT201 which is the slave. The UMFT201 itself being plugged into your PC, you can therefore implement a I2C communication form the micro-controller to the PC. For the micro-controller the PC is an I2C slave with an address of 22h.

You may want to find a an evaluation board like the FTDI FT260 (C samples available) or the device Nusbio.net (C#, VB, PowerShell samples available) based on the FTDI FT2301X which both are I2C master.

This make I2C communication easier as you can talk from your PC to any I2C slave device.

Here is a sample to talk I2C to an LCD screen with C# or vb.net