SPI - Serial Peripheral Interface

The Serial Peripheral Interface is a Serial Bus for peripherals that uses Clock, Data In, and Data Out (and often a Chip Select pin).

See SPI Class in the reference

Hardware SPI

On most boards there are hardware SPI peripherals. Check out the pin diagram on the reference page for your board and look for pins marked with an SPI tag.

You can use it as follows.

// set up SPI
SPI1.setup({mosi:B5, miso:B4, sck:B3});

// write data without a response
SPI1.write([1,2,3,4])

// write data with a response
var d = SPI1.send([1,2,3,4]);

See the reference for SPI.setup for more information on the arguments that can be passed in.

Software SPI

If you don't have access to your board's pins, you can also emulate SPI in software:

// set up SPI
var spi = new SPI();
spi.setup({mosi:B5, miso:B4, sck:B3});

// write data without a response
spi.write([1,2,3,4])

// write data with a response
var d = spi.send([1,2,3,4]);

Speed (baud rate)

Pretty much all SPI devices are guaranteed to support 100kBits/sec transfer speed, so that is the default in Espruino. However you can specify higher speeds with bitrate in SPI.setup if your device supports it, eg:

SPI1.setup({ mosi:B5, miso:B4, sck:B3, baud: 400000 });

Note: baud rate is ignored for software SPI - it will always send as fast as possible.

Using SPI

W25Qxx and W25Xxx Serial NOR Flash SSD16XX e-Paper display driver ST7735 LCD controller ST7789 LCD controller ILI9341 LCD controller SSD1306 OLED driver SSD1606 e-Paper display driver PCD8544 LCD driver (Nokia 5110) ADNS5050 Optical Mouse Sensor SH1106 OLED driver MFRC522 NFC/RFID module MAX7219 7 segment display driver SSD1351 OLED display driver Sharp Memory LCD ILI9163 LCD controller LIS302DL Accelerometer SX1276/77/78/79 LoRa Modules MCP4xxx0 SPI digital potentiometers ST7565/ST7567 128x64 Monochrome LCD driver XPT2046 AT25xxx SPI EEPROMs (incl. M95xxx, 25AAxxx, 25LCxxx, CAT25xxx, BR25Sxxx) SH1107 OLED driver LIS2DH12 Accelerometer Touchscreen HopeRF RFM69 Wireless Module MCP4xxx I2C and SPI digital potentiometers MCP23xxx I2C and SPI port expanders ADS7843 Touchscreen