HydraFW 1 wire guide - hydrabus/hydrafw GitHub Wiki

HydraFW Bus 1-wire

This guide is updated towards firmware release HydraFW v0.11 and later

Bus: 1-wire
Connections: One pin and ground
Output types: open drain/open collector
Pull-up resistors: required for open drain output mode (2K – 10K).
Pull-up/down resistors Integrated in MCU: Between 30 to 50K (Typical 40K).
Maximum voltage: 5.5volts (5volt safe)

Protocol configuration syntax description:

  • show Show 1-wire parameters or show pins Show pins used in this mode

  • pull with parameter up or down or floating to choose internal MCU pull up/down or no pull/external

  • msb-first or lsb-first to send/receive respectively MSB first or LSB first.

  • scan Discovers one or multiple devices on the 1-wire bus and displays their addresses.

  • exit to exit 1-wire mode

Note default value: 
    > 1-wire 
    Device: onewire1
    GPIO resistor: floating
    Bit order: LSB first

Configuration options:

Hardware Informations:

onewire1> show pins 
PIN: PB11

Protocol configuration example:

Configuration of onewire1 wit internal pullup :

> 1-wire 
Device: onewire1
GPIO resistor: floating
Bit order: LSB first
onewire1> pull up
onewire1> show 
Device: onewire1
GPIO resistor: pull-up
Bit order: LSB first
onewire1> 

Protocol interaction syntax description:

Bus interaction commands

trigger configures the trigger mode

Protocol interaction example usage onewire1 write/read:

onewire1> scan 
Discovered devices : 28 FF 10 2E A6 15 01 3B 
onewire1> [ 0x33 hd:8
WRITE: 0x33
28 FF 10 2E A6 15 01 3B                           |  (......; 

Additional informations about 1-wire

For more information about the 1-wire protocol, see : https://www.maximintegrated.com/en/app-notes/index.mvp/id/1796