SPI.begin()
Syntax
SPI.begin() // Only available with setSPI()
(extra) SPI.begin(spiDeviceName)
See setSPI()
Parameters
spiDeviceName:
The linux spi device path (e.g., "/dev/spidev0.0").
Returns
None
Example
Javascript
const linuxduino = require('linuxduino');
// Testing SPI beginTransaction
(async() => {
// Wait for wasm file
await linuxduino.ready;
// Open SPI port
SPI = new linuxduino.SPI();
SPI.begin("/dev/spidev0.0");
// Set SPI Settings
settingsA = new linuxduino.SPISettings(linuxduino.SPI_CLOCK_DIV64,
linuxduino.MSBFIRST, linuxduino.SPI_MODE3);
// Send Hello World! every second
buff = Buffer.from("Hello World!\n");
var ret;
while(1) {
SPI.beginTransaction(settingsA);
// Note in SPI the last character will not be printed here.
// In SPI you recieve what you sent previously.
for(var i=0; i<buff.length; i++) {
ret = SPI.transfer(buff[i]); // Transmit and receive one byte
process.stdout.write(String.fromCharCode(ret));
}
SPI.endTransaction();
process.stdout.write('\n');
linuxduino.delay(1000); // delay 1 sec.
}
SPI.end();
})();
Run it
sudo node spi_beginTransaction.js
C++
#include "Linuxduino.h"
// Testing SPI beginTransaction
int main(void) {
char ret;
// Open SPI port
SPI.begin("/dev/spidev0.0");
// Set SPI Settings
SPISettings settingsA(SPI_CLOCK_DIV64, MSBFIRST, SPI_MODE3);
// Send Hello World! every second
while(1) {
SPI.beginTransaction(settingsA);
// Note in SPI the last character will not be printed here.
// In SPI you recieve what you sent previously.
for (const char *p = "Hello, world!\n" ; *p!=0 ; p++) {
ret = SPI.transfer (*p); // Transmit and receive one byte
printf("%c", ret);
}
SPI.endTransaction();
printf("\n");
delay(1000); // delay 1 sec.
}
SPI.end();
return 0;
}
Run it
g++ spi_beginTransaction.cpp -o spi_beginTransaction -llxduino
sudo ./spi_beginTransaction