i2c

import {I2c} from 'mikro/i2c'

Communicate with I2CInter-Integrated Circuit devices such as temperature sensors, displays, and EEPROMs.

Usage

import {I2c} from 'mikro/i2c'

const bus = I2c(0, {sda: 6, scl: 7, freq: 400000}).orPanic('I2C init failed')

// Scan for devices
const devices = bus.scan().orPanic('scan failed')
console.log('Found devices at: %o', Array.from(devices))

// Read 2 bytes from device at address 0x44
const data = bus.read(0x44, 2).orPanic('read failed')

bus.end()

Functions

I2c(bus, options)

function I2c(bus: number, options: I2cOptions): Result<I2c, I2cError>

Claims the sda and scl pins, starts the bus and returns a Result with the handle. Both pins must be able to drive a signal, or you get InvalidGpio. If another handle, a peripheral or the console holds one of them, you get GpioInUse.

Parameters:

• bus: I2CInter-Integrated Circuit controller. The ESP32 and ESP32-S3 have buses 0 and 1; the ESP32-C3 and ESP32-C6 have bus 0 only. Any other number returns InvalidParam.
• options: see I2cOptions

Methods

bus.end()

end(): void

Deletes the bus and releases its GPIOGeneral-Purpose Input/Output pins. Calling it again does nothing. After end(), write() does nothing, read() and scan() return an empty array, and the first such call prints a warning. The handle keeps the hardware and its GPIOGeneral-Purpose Input/Output pins until you call end(), even when your code no longer refers to the handle.

bus.read(address, bytes)

read(address: number, bytes: number): Result<Uint8Array, I2cError>

Read bytes bytes from the device at address. An address outside 0 to 0x7f, or a byte count that is not a whole number from 1 to 65535, returns InvalidParam.

bus.write(address, data, stop?)

write(address: number, data: Uint8Array, stop?: boolean): Result<void, I2cError>

Write data to the device at address. Set stop to false to send without a stop condition (for repeated start).

bus.scan()

scan(): Result<Uint8Array, I2cError>

Scan the bus and return an array of addresses that responded.

Types

I2cOptions

interface I2cOptions {
  sda: number // SDA pin
  scl: number // SCL pin
  freq?: number // clock frequency in Hz (default: 100000)
  timeout?: number // timeout per operation in ms (default: 100)
}

Errors

I2cError

Variant	Fields	Description
GpioInUse	owner, message	A pin is held by another handle, peripheral or the console
InvalidGpio	message	The chip has no such GPIOGeneral-Purpose Input/Output, or the GPIOGeneral-Purpose Input/Output cannot drive a signal
InvalidParam	message	The bus, an option, an address or a read length is out of range
BusInitFailed	message	Failed to initialize the bus
AddDeviceFailed	message	Failed to add device to bus
WriteFailed	message	Write operation failed
WriteTooLarge	—	Write data exceeds buffer size
ReadFailed	message	Read operation failed