Fly UTOC CAN bus Termination
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UTOC CAN bus termination jumpers

Fly UTOC CAN bus termination

  • The Fly UTOC main CAN bus 120 ohm resistor is not jumpered and always enabled.
  • CAN bus must have two 120 ohm resistors. One at each end of the bus.
  • Failure to correctly terminate the CAN bus cause to communication issues and instability.
  • No matter how many USB devices you connect on a singe bus only enable one 120 ohm resistor at each end of the bus. There is no need to add a resistor to every CAN device
  • The resistance between CAN H and CAN L measured with the system powerd off should be 60 ohms with all CAN devices connected.
  • The UTOC-3 USB-A ports provide a CAN transciever and termination for an attached STM32 device that does not have it’s own can transciever.
Fly UTOC-3 120R jumpers
Fly UTOC-3 120R jumpers
  • The Fly UTOC has an on-board 120 ohm resistor for the USB-A ports. They are enabled by installing a jumper as shown in the picture above.
Fly UTOC-3 5v jumpers
Fly UTOC-3 5v jumpers
  • The Fly UTOC has jumpers to supply +5v to the USB-A ports and JST_XH sockets if the connected CAN device requires power from the Fly UTOC