Class SPISettings_SPIClass
SPISettings Class
Description
Defines a class to set SPI parameters.
Syntax
class SPISettings
Members
Public Constructors |
|
|---|---|
SPISettings::SPISettings |
Create a SPISettings object and set SPI clock speed, bit order and data mode |
SPISettings::SPISettings
Description
Construct an object and configure SPI parameters — clock speed, bit
order and data model to the preferred default value.
Syntax
SPISettings YourObject(uint32_t clock, BitOrder bitOrder, uint8_t
dataMode);
Parameters
clock: SPI clock speed, default is 4000000
bitOrder: order of bit stream, MSB first or LSB first, default is
MSBFIRST
dataMode: There are 4 modes -> SPI_MODE0~3, default is SPI_MODE0
Returns
The function returns nothing.
Example Code
NA
Notes and Warnings
This class seldom used alone, it is always used with
beginTransaction() as a parameter in SPIClass.
SPIClass Class
Description
Defines a class of SPI implementation for Ameba.
Syntax
class SPIClass
Members
Public Constructors |
|
|---|---|
SPIClass::SPIClass |
Constructs an SPI object |
Public Methods |
|
SPIClass::transfer |
Transfer data through SPI |
SPIClass::transfer16 |
Transfer a 16-bits data through SPI |
SPIClass::beginTransaction |
Set slave select pin and SPI initial settings |
SPIClass::endTransaction |
Stop SPI transaction |
SPIClass::begin |
Associate each SPI pin to Ameba pin using ameba HAL APIs |
SPIClass::end |
Stop SPI master mode |
SPIClass::setBitOrder |
Set MSB first or LSB first |
SPIClass::setDataMode |
Set to one of the four data modes |
SPIClass::setClockDivider |
Set to correct clock speed (no effect on Ameba) |
SPIClass::setDefaultFrequency |
Set default SPI frequency |
SPIClass::SPIClass
Description
Construct an SPI object, create a pointer to the object, and attach
“MOSI, MISO, CLK, and SS” to each pin on Ameba.
Syntax
SPIClass(void *pSpiObj, int mosi, int miso, int clk, int ss);
Parameters
pSpiObj: SPI pointer to the object
mosi: master out slave in
miso: master in slave out
clk: clock
ss: slave select
Returns
The function returns nothing.
Example Code
SPIClass SPI((void *)(&spi_obj0), 11, 12, 13, 10);
Notes and Warnings
2 SPI objects are created in the library for 2 different hardware SPI
on Ameba (if applicable), use “SPI” for first hardware SPI and “SPI1”
for the second.
SPIClass::transfer
Description
Calling HAL API to send data in the buffer to the slave
Syntax
byte SPIClass::transfer (byte _pin, uint8_t _data, SPITransferMode
_mode);
byte SPIClass::transfer (uint8_t _data, SPITransferMode _mode);
void SPIClass::transfer (byte _pin, void *_buf, size_t _count,
SPITransferMode _mode);
void SPIClass::transfer (void *_buf, size_t _count, SPITransferMode
_mode);
Parameters
_pin: Slave select pin
_data: Actual data being sent over
_mode: SPI transfer mode
_count: number of bytes of data
_buf: data buffer
Returns
Void or “0” in case of error, “d” in case success
Example Code
NA
Notes and Warnings
NA
SPIClass::transfer16
Description
Same as “transfer” method above except data being of 16-bits.
Syntax
uint16_t SPIClass::transfer16(byte _pin, uint16_t _data,
SPITransferMode _mode)
uint16_t SPIClass::transfer16(uint16_t _data, SPITransferMode _mode)
Parameters
_pin: Slave select pin
_data: Actual data being sent over
_mode: SPI transfer mode
Returns
The data being transferred
Example Code
NA
Notes and Warnings
NA
SPIClass::beginTransaction
Description
Set slave select pin and initialize SPI with default settings using
SPISettings class.
Syntax
void SPIClass::beginTransaction(uint8_t pin, SPISettings settings)
void SPIClass::beginTransaction(SPISettings settings)
Parameters
pin: slave select pin
settings: an object of SPISettings class
Returns
The function returns nothing.
Example Code
NA
Notes and Warnings
Refer to SPISettings class for details of the initial settings.
SPIClass::endTransaction
Description
Set slave select pin to 1 and stop SPI transaction.
Syntax
void SPIClass::endTransaction(void);
Parameters
The function requires no input parameter.
Returns
The function returns nothing.
Example Code
NA
Notes and Warnings
NA
SPIClass::begin
Description
Calling HAL APIs to initialize SPI pins to physical Ameba pins and set
SPI format and frequency
Syntax
void SPIClass::begin(void)
void SPIClass::begin(int ss)
Parameters
void or ss: slave select
Returns
The function returns nothing.
Example Code
NA
Notes and Warnings
This is a required method to use SPI on Ameba.
SPIClass::end
Description
Free hardware SPI from any activity.
Syntax
void SPIClass::end(void);
Parameters
The function requires no input parameter.
Returns
The function returns nothing.
Example Code
NA
Notes and Warnings
NA
SPIClass::setBitOrder
Description
A specific method to set bit order to either MSB first or LSB first
and set slave select pin.
Syntax
void SPIClass::setBitOrder(uint8_t _pin, BitOrder _bitOrder)
void SPIClass::setBitOrder(BitOrder _order)
Parameters
_pin: slave select
_bitOrder: bit order -> either MSB first or LSB first
_order: same as above
Returns
The function returns nothing.
Example Code
NA
Notes and Warnings
NA
SPIClass::setDataMode
Description
A specific method to set data mode to one of the 4 modes (default:
SPI_MODE0) and set slave lave select pin.
Syntax
void SPIClass::setDataMode(uint8_t _pin, uint8_t _mode)
void SPIClass::setDataMode(uint8_t _mode)
Parameters
_pin: slave select
_mode: one of the 4 modes (default: SPI_MODE0)
Returns
The function returns nothing.
Example Code
NA
Notes and Warnings
NA
SPIClass::setClockDivider
Description
A specific method to set to divider in order to get correct clock
speed
Syntax
void SPIClass::setClockDivider(uint8_t _pin, uint8_t _divider)
void SPIClass::setClockDivider(uint8_t _div)
Parameters
_pin: slave select
_divider: clock divider
_div: same as above
Returns
The function returns nothing.
Example Code
NA
Notes and Warnings
This function does not affect the Ameba board.
SPIClass::setDefaultFrequency
Description
A specific method to set default SPI frequency
Syntax
void SPIClass::setDefaultFrequency(int _frequency)
Parameters
_frequency: the default SPI frequency
Returns
The function returns nothing.
Example Code
Example: PM25_on_ILI9341_TFT_LCD
Details of the code are given in the previous section of
AmebaILI9341:: AmebaILI9341.
Notes and Warnings
Take note that defaultFrequency = _frequency.