HydraFW 1 wire guide

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.

• debug Use the 1-wire line as a SWIO debugger probe compatible with minichlink

• 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

SWIO protocol interaction

Since a2d1f57d96c454d93113f98bfb4391cf17cc0d42, Hydrabus can be used to program SWIO-enabled microcontrollers like CH32V003. The debug spawns a "Ardulink" interface that can be used with minichlink.

Note that an external 1K pullup resistor must be added in order to work correctly. The STM32F405 internal pullups are too strong and don't allow the line to rise fast enough.