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I have a technical question about connecting the Aardvark I2C/SPI Host Adapter to a new design that is in development.

We are looking for the ability to detect whether the Aardvark adapter is connected based on the voltage level on pin 10, which is supposed to be a GND connection.  AARDVARK_CON_nDETECT, a signal from our controller,  will be used for automatically enabling an internal level shifter – the  functionally is similar to your Level Shifter Board -  when the Aardvark adapter is connected.

• When the Aardvark adapter is disconnected, the signal AARDVARK_CON_nDETECT is pulled high.
• When the Aardvark adapter is connected, the signal AARDVARK_CON_nDETECT is pulled low, which enables the Aardvark adapter to program the clock generator signal with the internal level shifter.

The question we have - is it sufficient to only connect pin 2 to GND, and then use pin 10 to detect the Aardvark adapter? Note – on our board, the ground closest to the I2C pins is the actual ground.

Thank you for your question! Based on Aardvark adapter GND pins and the speed of the I2C bus, the design that you described should work.

Aardvark Host Adapter and Ground Connections

Your design should work because the two GND pins are common on the Aardvark adapter. To optimize the connection, it is always best to have more grounds tied down as real ground wires. However, as the I2C bitrate is relatively slow, your design should be functional.

Software Options for Selection

There are two options regarding selection, which are available separately in our software applications.

• When using Flash Center Software, you can use the +5V Target Power for selection.
• When using Aardvark Software API, you can use the SPI interface in GPIO mode, and then use a GPIO pin for selection. For information about API commands, refer to section 5 API Documentation of the Aardvark I2C/SPI Host Adapter User Manual, which includes details about the commands per mode: I2C, SPI, and GPIO.

We hope this answers your questions. Additional resources that you may find helpful include the following:

• Aardvark I2C/SPI Host Adapter User Manual
• Level Shifter Board User Manual
• Flash Center Software User Manual
• I2C Background

If you want more information, feel free to contact us with your questions, or request a demo that applies to your application.