spi - spi Operation Library

Adapted Air780E Air780EP Air780EPS Air700EAQ Air700EMQ Air700ECQ Air201

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This library has its own demo,click this link to view the demo example of spi

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There are also video tutorials in this library, click this link to view

Constant

constant	type	explanation
spi.MSB	number	Big Endian Mode
spi.LSB	number	Little Endian Mode
spi.master	number	Host Mode
spi.slave	number	slave mode
spi.full	number	Full Duplex
spi.half	number	half duplex
spi.SPI_0	number	SPI0
spi.SPI_1	number	SPI1
spi.SPI_2	number	SPI2
spi.SPI_3	number	SPI3
spi.SPI_4	number	SPI4
spi.HSPI_0	number	High-speed SPI0, currently 105 dedicated

spi.setup(id, cs, CPHA, CPOL, dataw, bandrate, bitdict, ms, mode)

Set up and enable SPI

Parameters

Incoming Value Type	Explanation
int	SPI No., for example 0
int	CS Foot selection, not available in w600, please fill in nil
int	CPHA Default 0, optional 0/1
int	CPOL Default 0, optional 0/1
int	Data width, default 8bit
int	baud rate, default 2M=2000000
int	Size side, default spi.MSB, optional spi.LSB
int	Master-slave setting, default master 1, optional slave 0. Generally, only host mode is supported
int	Operating mode, full duplex 1, half duplex 0, default full duplex

Return Value

return value type	explanation
int	Returns 0 on success, otherwise returns another value

Examples

-- Initialization spi
spi.setup(0,20,0,0,8,2000000,spi.MSB,1,1)

---

spi.createSoft(cs, mosi, miso, clk, CPHA, CPOL, dataw, bitdict, ms, mode)

Set up and enable the software SPI

Parameters

Incoming Value Type	Explanation
int	cs Pin number, incoming nil means Lua controls cs pin
int	mosi Pin number
int	miso Pin number
int	clk Pin number
int	Default 0, optional 0/1
int	Default 0, optional 0/1
int	Data width, default 8bit
int	Size side, default spi.MSB, optional spi.LSB
int	Master-slave setting, default master 1, optional slave 0. Generally, only host mode is supported
int	Operating mode, full duplex 1, half duplex 0, default half duplex

Return Value

return value type	explanation
Software SPI object	can be used as the ID of the SPI

Examples

-- Initialize software spi
local softSpiDevice = spi.createSoft(0, 1, 2, 3, 0, 0, 8, spi.MSB, 1, 1)
local result = spi.send(softSpiDevice, string.char(0x9f))

---

spi.close(id)

Close the specified SPI

Parameters

Incoming Value Type	Explanation
int	SPI No., for example 0

Return Value

return value type	explanation
int	Returns 0 on success, otherwise returns another value

Examples

-- Initialization spi
spi.close(0)

---

spi.transfer(id, send_data, send_len, recv_len)

Transferring SPI Data

Parameters

Incoming Value Type	Explanation
int	SPI number (e. g. 0) or software SPI object
string/zbuff	The data to be sent. If it is zbuff data, it will be read from the pointer where the object is located.
int	Optional. The length of the data to be sent. The default value is the length of data.
int	Optional. The length of the read data. The default value is 1

Return Value

return value type	explanation
string	Read successfully returns the string, otherwise it returns nil

Examples

-- Initialization spi
spi.setup(0,nil,0,0,8,2000000,spi.MSB,1,1)
local recv = spi.transfer(0, "123")--Send 123 and read data

local buff = zbuff.create(1024, 0x33) --Create a memory area with all initial values of 0x 33
local recv = spi.transfer(0, buff)--Start zbuff data from the pointer, send it all out, and read the data

---

spi.recv(id, size, buff)

Receives SPI data of a specified length

Parameters

Incoming Value Type	Explanation
int	SPI No., for example 0
int	Data length
userdata	zbuff object, optional, 2024.3.29 New

Return Value

return value type	explanation
string/int	The string returned after the read is successful. If zbuff is passed in, the read size is returned. If an error is returned nil

Examples

-- Initialization spi
spi.setup(0,nil,0,0,8,2000000,spi.MSB,1,1)
-- Receive data
local recv = spi.recv(0, 4)--Receive 4 bytes of data

-- When the zbuff parameter is passed in, the return value is different. 2024.3.29 New
-- After a successful read, the pointer moves back len bytes
-- The write position starts with the current used() position, make sure there is enough space to write len-length data
local len = spi.recv(0, 4, buff)

---

spi.send(id, data[, len])

Send SPI Data

Parameters

Incoming Value Type	Explanation
int	SPI No., for example 0
string/zbuff	The data to be sent. If it is zbuff data, it will be read from the pointer where the object is located.
int	Optional. The length of the data to be sent. The default value is the length of data.

Return Value

return value type	explanation
int	Send Results

Examples

-- Initialization spi
spi.setup(0,nil,0,0,8,2000000,spi.MSB,1,1)
local result = spi.send(0, "123")--Send 123

local buff = zbuff.create(1024, 0x33) --Create a memory area with all initial values of 0x 33
local result = spi.send(0, buff)--Start the zbuff data from the pointer and send it all out.

---

spi.deviceSetup(id, cs, CPHA, CPOL, dataw, bandrate, bitdict, ms, mode)

Set up and enable SPI (object way)

Parameters

Incoming Value Type	Explanation
int	SPI No., for example 0
int	CS Foot selection, not available in w600, please fill in nil
int	CPHA Default 0, optional 0/1
int	CPOL Default 0, optional 0/1
int	Data width, default 8bit
int	baud rate, default 20M=20000000
int	Size side, default spi.MSB, optional spi.LSB
int	Master-slave setting, default master 1, optional slave 0. Generally, only host mode is supported
int	Operating mode, full duplex 1, half duplex 0, default full duplex

Return Value

return value type	explanation
userdata	spi_device

Examples

-- Initialization spi
local spi_device = spi.deviceSetup(0,17,0,0,8,2000000,spi.MSB,1,1)

---

spi_device:close()

Close the specified SPI (object way)

Parameters

Incoming Value Type	Explanation
userdata	spi_device

Return Value

return value type	explanation
int	Returns 0 on success, otherwise returns another value

Examples

-- Initialization spi
spi_device.close()

---

spi_device:transfer(send_data[, len])

Transfer SPI Data (Object Way)

Parameters

Incoming Value Type	Explanation
userdata	spi_device
string/zbuff	The data to be sent. If it is zbuff data, it will be read from the pointer where the object is located.
int	Optional. The length of the data to be sent. The default value is the length of data.
int	Optional. The length of the read data. The default value is 1

Return Value

return value type	explanation
string	Read successfully returns the string, otherwise it returns nil

Examples

-- Initialization spi
local spi_device = spi.device_setup(0,17,0,0,8,2000000,spi.MSB,1,1)
local recv = spi_device:transfer("123")--Send 123 and read data
local result = spi_device:transfer({0x00,0x01})--Send 0x 00,0x 01, and read data

local buff = zbuff.create(1024, 0x33) --Create a memory area with all initial values of 0x 33
local recv = spi_device:transfer(buff)--Start zbuff data from the pointer, send it all out, and read the data

---

spi_device:send(data[, len])

Send SPI Data (Object Way)

Parameters

Incoming Value Type	Explanation
userdata	spi_device
string/zbuff	The data to be sent. If it is zbuff data, it will be read from the pointer where the object is located.

Return Value

return value type	explanation
int	Send Results

Examples

-- Initialization spi
local spi_device = spi.device_setup(0,17,0,0,8,2000000,spi.MSB,1,1)
local result = spi_device:send("123")--Send 123
local result = spi_device:send({0x00,0x01})--Send 0x00,0x01

local buff = zbuff.create(1024, 0x33) --Create a memory area with all initial values of 0x 33
local result = spi_device:send(buff)--Start the zbuff data from the pointer and send it all out.

---

spi_device:recv(size)

Receives SPI data of a specified length (object method)

Parameters

Incoming Value Type	Explanation
userdata	spi_device
int	Data length

Return Value

return value type	explanation
string	Read successfully returns the string, otherwise it returns nil

Examples

-- Initialization spi
local spi_device = spi.device_setup(0,17,0,0,8,2000000,spi.MSB,1,1)
local recv = spi_device:recv(4)--Receive 4 bytes of data

---

spi.xfer(id, txbuff, rxbuff, rx_len, transfer_done_topic)

The non-blocking hardware SPI transfers SPI data in order to improve core utilization. The API directly returns whether to start the transmission or not. After the transmission is completed, the API is suitable for hardware SPI to transmit a large amount of data. SPI and software SPI occupied by peripheral functions (LCD SPI,W5500 SPI, etc.) cannot be used. Traditional blocking type is recommended for a small amount of data transmission.API

Parameters

Incoming Value Type	Explanation
userdata	or int spi_device Or spi_id, note that if it is spi_device, you need to manually pull it up after the transmission is completed.cs!!!!!!
zbuff	The data to be sent, if nil, only receives the data, because of the non-blocking model, in order to ensure the validity of the dynamic data, can only use zbuff, the data sent from.zbuff.addr
zbuff	Receive data, if it is nil, only send data, due to the non-blocking model, in order to ensure the validity of dynamic data, only zbuff can be used, and the received data is stored from zbuff.addr.
int	The length of the transmitted data, especially if it is half duplex, send before receive, such as spi flash operation, then the length = send byte receive byte, note that the above send and receive buff should leave enough data, subsequent receive data processing needs to skip the send data length byte
string	The callback after the transfer is complete topic

Return Value

return value type	explanation
boolean	true/false Whether this transmission is started correctly, true, start, false, and cannot be started with errors. Message transfer_done_topic and boolean results are published when the transfer is complete

Examples

local result = spi.xfer(spi.SPI_0, txbuff, rxbuff, 1024, "SPIDONE") if result then result, spi_id, succ, error_code = sys.waitUntil("SPIDONE") end if not result or not succ then log.info("spi fail, error code", error_code) else log.info("spi ok") end

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