Document

obniz Hardware and cloud specifications.

Peripherals SPI

It is General Purpose SPI
spi0 and spi1 are available.

obniz.getFreeSpi()

It returns unused spi.

var spi = obniz.getFreeSpi();

It shows error when no more spi is available.

var spi0 = obniz.getFreeSpi();
var spi1 = obniz.getFreeSpi();
var spi2 = obniz.getFreeSpi(); // Error

start({mode, clk, mosi, miso, frequency, [, drive, pull, gnd] } );

It starts spi. Now the mode is only "master".
drive and pull are optional settings for io output.
Default settings are drive:5v, pull:null.
See more using obniz.io.drive() or pull().

// Javascript Example
obniz.spi0.start({mode:"master", clk :0, mosi:1, miso:2, frequency:1000000}); 
var ret = await obniz.spi0.writeWait([0x12, 0x98]);
console.log("received: "+ret);

// drive and pull is optional
obniz.spi0.start({mode:"master", clk :0, mosi:1, miso:2, frequency:1000000, drive: "5v", pull:null}); 

[await] writeWait(data);

It sends data to spi and wait until data are received.
The received data length is the same as the sent data.
Max length is 1024 bytes.

// Javascript Example
obniz.spi0.start({mode:"master", clk :0, mosi:1, miso:2, frequency:1000000}); 
var ret = await obniz.spi0.writeWait([0x12, 0x98]);
console.log("received: "+ret);

write(data);

It only sends data to spi and does not receive it.
Max length is 1024 bytes.

// Javascript Example
obniz.spi0.start({mode:"master", clk :0, mosi:1, miso:2, frequency:1000000}); 
obniz.spi0.write([0x12, 0x98]);

end();

It ends spi

// Javascript Example
obniz.spi0.start({mode:"master", clk :0, mosi:1, miso:2, clock:1000000}); 
obniz.spi0.write([0x12, 0x98]);
obniz.spi0.end();