spi

import {Spi} from 'mikro/spi'

Communicate with SPISerial Peripheral Interface devices such as displays, SD cards, and radio modules.

Usage

import {Spi} from 'mikro/spi'

const spi = Spi(1, {clk: 4, mosi: 5, miso: 6, cs: 7, freq: 1000000}).orPanic('SPI init failed')

// Write data
spi.write(new Uint8Array([0x01, 0x02])).orPanic('write failed')

// Transfer (write and read simultaneously)
const response = spi.transfer(new Uint8Array([0x00, 0x00])).orPanic('transfer failed')

spi.end()

Functions

Spi(host, options)

function Spi(host: number, options: SpiOptions): Result<Spi, SpiError>

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

Parameters:

• host: SPISerial Peripheral Interface host controller. Host 1 is SPI2 and host 2 is SPI3; SPI0 and SPI1 drive the flash. The ESP32, ESP32-S2 and ESP32-S3 have hosts 1 and 2, and chips with one general-purpose SPISerial Peripheral Interface controller, such as the ESP32-C3 and ESP32-C6, have host 1 only. Any other number returns InvalidParam.
• options: see SpiOptions

Methods

spi.end()

end(): void

Frees the bus and releases its GPIOGeneral-Purpose Input/Output pins. Calling it again does nothing. After end(), write() does nothing, transfer() returns 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.

spi.transfer(data)

transfer(data: Uint8Array): Result<Uint8Array, SpiError>

Full-duplex transfer: sends data and returns the bytes received simultaneously.

spi.write(data)

write(data: Uint8Array): Result<void, SpiError>

Write-only transfer. Discards received data.

Types

SpiOptions

interface SpiOptions {
  clk: number // clock pin
  mosi: number // MOSI (Master Out Slave In) pin
  miso?: number // MISO pin (optional for write-only)
  cs?: number // chip select pin (optional, manage manually if omitted)
  freq?: number // clock frequency in Hz (default: 1000000)
  mode?: 0 | 1 | 2 | 3 // SPI mode (default: 0)
}

Errors

SpiError

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 host or frequency is out of range
BusInitFailed	message	Failed to initialize the bus
AddDeviceFailed	message	Failed to add device to bus
TransferFailed	message	Full-duplex transfer failed
WriteFailed	message	Write operation failed