spi Transfer
Send a command over a SPI connection and receive a response.
pins.spiTransfer(null, null)Command data in Buffer is sent to an SPI slave device. The format of the data in the command buffer depends on how the connected device expects to read it.
Parameters
- command: a Buffer that contains the command data to send to the slave device.
- response: a Buffer that will receive the data for the response to command.
Example
Send some text to show on an alphanumeric LCD display. The display is connected by SPI and the display command is 2. The command buffer formatted for the display contains both the command and the text string Hello!.
let resBuff = pins.createBuffer(2)
let cmdBuff = pins.createBuffer(16)
let message = "Hello!"
cmdBuff.setUint8(0, 2)
for (let i = 0; i <= message.length - 1; i++) {
cmdBuff.setUint8(i+1, message.charCodeAt(i))
}
pins.spiTransfer(cmdBuff, resBuff)