UNI/O General

The UNI/O protocol was created by microchip and is a 1 wire bus.

Docs

Voltage Range

Not specified by the protocol so dependent on the devices being used.

Circuit

A pull up resistor is not required but advisable so the bus is idle if the master is not driving it. The value is dependent on bus voltage and other factors – see here. Based on the calculation is this datasheet:

5V bus, Rpmin = 15K33, Rpmax = 150K

3V3 bus, Rpmin = 9K666, Rpmax = 99K

Max cable length

We couldn’t find a reliable source of info on this. In our bench based tests, using unscreened (not a good idea!) 3 core 7/0.2mm cable, we had comms working fine over 31m. When testing at 100m comms would not work at all. This was with the bus speed set to slowest allowed (10kHz).

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Docs

Voltage Range

Circuit

Max cable length

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