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I2C on EHS6T:USB Terminal | Telit Cinterion IoT Developer Community

July 12, 2015 - 12:08pm, 8653 views

I am having problems using the I2C bus to communicate to a 3V I2C LCD display (Address: 7C). This is what I have done:-

Set: AT^SCFG="Gpio/mode/SPI","std"

Response: ^SCFG: "Gpio/mode/SPI","std"

Set: at^sspi=

Response: CONNECT

Set: <a7C>

Response: {a+}

Set: <a7C0038>

Response: {a-0002}

I am using 4k7ohm resistors fitted between the bus lines and a regulated 3.3V supply.

I have the I2C display working with a freescale FRDM-KL25Z using Mbed compiler and standard library functions/programs so I know the LCD works. 

Even if I disconnect everything from the terminals connector and type <a7C> i get {a+} even if I type any random two Hex numbers like <a22> it returns {a+}. This seems a little strange.

Any help/advice most welcome.