I2C Functions

dev.io.i2c - wire path i\i - generated from fwMenuI2C.

i2c_write

Write. Writes data to a specific I2C Address

Requires power zone 6 (FPGA). See Errors.

Wire command: i\i\w

Arg	Wire type
address	hex8
register	hex8
data_bytes	hexbytes

Returns: none (Ok/Err only)

dev.io.i2c.i2c_write(address: int, register: int, data_bytes: bytes | bytearray) -> Result

ow_status ow_io_i2c_i2c_write(ow_device* dev, uint8_t address, uint8_t register_, const uint8_t* data_bytes, size_t data_bytes_len);

dev.io().i2c().i2c_write(address: u8, register: u8, data_bytes: &[u8]) -> Result<(), OwError>

The C and Rust signatures above are also the WASM guest signatures - the device API surface is identical; only the transport differs (ow_open_wasm(&dev) in C, OneWili::open() in Rust).

dev.io.i2c.i2c_write(address, register, data_bytes)   # check dev.ok

i2c_read

Read. Reads the number from the address

Requires power zone 6 (FPGA). See Errors.

Wire command: i\i\r

Returns: i2crepsone (hexbytes)

dev.io.i2c.i2c_read() -> Result

ow_status ow_io_i2c_i2c_read(ow_device* dev, uint8_t* i2crepsone, size_t i2crepsone_cap, size_t* i2crepsone_len);

dev.io().i2c().i2c_read() -> Result<Vec<u8>, OwError>

The C and Rust signatures above are also the WASM guest signatures - the device API surface is identical; only the transport differs (ow_open_wasm(&dev) in C, OneWili::open() in Rust).

dev.io.i2c.i2c_read()   # returns value; check dev.ok

i2c_poll

Poll. Tests all addresses for I2C Response

Requires power zone 6 (FPGA). See Errors.

Wire command: i\i\p

Returns: none (Ok/Err only)

dev.io.i2c.i2c_poll() -> Result

ow_status ow_io_i2c_i2c_poll(ow_device* dev);

dev.io().i2c().i2c_poll() -> Result<(), OwError>

The C and Rust signatures above are also the WASM guest signatures - the device API surface is identical; only the transport differs (ow_open_wasm(&dev) in C, OneWili::open() in Rust).

dev.io.i2c.i2c_poll()   # check dev.ok

i2c_slave_enable

I2C Slave Enable. Enables I2C slave mode at the given 7-bit address; 0 disables

Requires power zone 6 (FPGA). See Errors.

I2C Slave Enable

Turns this device into an I2C slave on the breakout bus (SDA 16 / SCL 17) at the given 7-bit address, backed by a 256-byte register file with auto-incrementing pointer semantics.

Usage

e 17
e 0

e 17 enables slave mode at address 0x17; e 0 disables it and returns the bus to master mode using the current I2C settings.

Behavior

• While slave mode is active the master items (Write, Read, Poll) report Failed.
• Master writes received by the slave are streamed as i2cslv events (register followed by the data bytes).
• Seed the register file with Set I2C Slave Data (l).

Arguments

• address — 7-bit slave address in hex; 0 disables slave mode.

Wire command: i\i\e

Arg	Wire type
address	hex8

Returns: none (Ok/Err only)

dev.io.i2c.i2c_slave_enable(address: int) -> Result

ow_status ow_io_i2c_i2c_slave_enable(ow_device* dev, uint8_t address);

dev.io().i2c().i2c_slave_enable(address: u8) -> Result<(), OwError>

The C and Rust signatures above are also the WASM guest signatures - the device API surface is identical; only the transport differs (ow_open_wasm(&dev) in C, OneWili::open() in Rust).

dev.io.i2c.i2c_slave_enable(address)   # check dev.ok

i2c_slave_set_data

Set I2C Slave Data. Writes bytes into the I2C slave register file

Requires power zone 6 (FPGA). See Errors.

Set I2C Slave Data

Seeds the I2C slave register file: the first byte is the starting register index, the rest are data bytes stored from there.

Usage

l 00 DE AD BE EF

Stores DE AD BE EF at registers 0x00-0x03.

Behavior

• Works whether or not slave mode is currently enabled; the register file persists across enable/disable.
• Bounds-checked against the 256-byte register file.

Arguments

• dataBytes — register index followed by one or more data bytes, all hex.

Wire command: i\i\l

Arg	Wire type
data_bytes	hexbytes

Returns: none (Ok/Err only)

dev.io.i2c.i2c_slave_set_data(data_bytes: bytes | bytearray) -> Result

ow_status ow_io_i2c_i2c_slave_set_data(ow_device* dev, const uint8_t* data_bytes, size_t data_bytes_len);

dev.io().i2c().i2c_slave_set_data(data_bytes: &[u8]) -> Result<(), OwError>

The C and Rust signatures above are also the WASM guest signatures - the device API surface is identical; only the transport differs (ow_open_wasm(&dev) in C, OneWili::open() in Rust).

dev.io.i2c.i2c_slave_set_data(data_bytes)   # check dev.ok

Events

Spontaneous frames this menu emits (not command responses). Text events arrive as [*<id> ...] frames (Python: Transport.events; C: ow_poll_text_event; Rust: poll_event -> Event::Text); binary events use the binary API below. The on-device rthon binding does not receive event streams in v1.

i2cmon (text)

I2C monitor captured bytes

Payload field	Wire type
data_bytes	hexbytes

i2cslv (text)

I2C slave received master write (register, data bytes)

Payload field	Wire type
data_bytes	hexbytes

Sub-menus

• I2C Settings - dev.io.i2c.settings