Connecting to the serial UART header on the Infinity CPU board

Updated by Bryan Jones


The Infinity CPU Board is used on a number of products including Telos Infinity, Axia IQx, iQs, 25-Seven PDM II, and some Linear Acoustic products.


This board has a serial UART header that is helpful if doing advanced troubleshooting. This port can not be used for configuration, etc. If you are reading this doc hoping to find configuration or other information from this port, move along. There is nothing to see here.

This port is labeled J6 UART and is located along the long edge of the board (opposite the ethernet connectors) next to the MicroSSD slot.


The serial line voltages on this board are "TTL level", not the more standard "RS232 level." You need an "active" cable for this. A standard serial cable or even a USB RS323 adapter will not work. You need some kind of active USB to TTL Serial 3.3V UART Converter Cable. At the time of this writing, here's an Amazon link.

USB to TTL Serial 3.3V UART Converter Cable with FTDI Chip Terminated by 6 Way Header, Works with Galileo Gen2 Boards/BeagleBone Black/Minnowboard Max and Moreby Easy4Work

The pinouts are defined as follows (note: pin 1 is closest to the edge of the board):

  • Pin 1 - +3V3 (leave unconnected)
  • Pin 2 - Transmit (generally White)
  • Pin 3 - Receive (generally Green)
  • Pin 4 - Ground (generally Black)
NOTE, Pin 1 has +3V DC; unless instructed otherwise, do NOT connect anything to this pin. Please be cautious connecting your serial port cable to not damage your device or short out this board. Shorted boards or damage as a result of misuse are not covered as a warranty repair.

Image of the entire board for orientation purposes.

Cables and other components were removed for clarity.

Close up of the J6 UART header

Properly connected cable

Note, no connection to Pin 1

Terminal Settings

Adjust your setting in your terminal program as shown here;

  • Baud Rate - 115,200
  • Data Bits - 8
  • Stop Bits - 1
  • Parity - None
  • Flow Control - None

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