SpiDevice Class Reference

Represents a peripheral attached to the SPI bus More...

Public Member Functions
	SpiDevice (Spi spiModule, SpiChipSelectPin chipSelect, ChipSelectMode chipSelectMode=ChipSelectMode.SpiActiveLow, double speedMhz=6, SpiMode mode=SpiMode.Mode00)
	Construct an SPI device attached to a particular module More...
Task< byte[]>	SendReceiveAsync (byte[] dataToSend, SpiBurstMode burst=SpiBurstMode.NoBurst)
	Start an SPI transaction More...

Properties
SpiChipSelectPin	ChipSelect [get, protected set]
	Get or set the pin to use for chip-select duties. More...
SpiMode	Mode [get, protected set]
	Get or set the SPI module's mode More...
double	Frequency [get, set]
	Gets or sets the Frequency, in MHz, that this device will use for SPI communication. More...
ChipSelectMode	ChipSelectMode [get, protected set]
	The chip select mode to use with transactions More...

Detailed Description

Represents a peripheral attached to the SPI bus

Constructor & Destructor Documentation

SpiDevice()

SpiDevice	(	Spi	spiModule,
		SpiChipSelectPin	chipSelect,
		ChipSelectMode	chipSelectMode = ChipSelectMode.SpiActiveLow,
		double	speedMhz = 6,
		SpiMode	mode = SpiMode.Mode00
	)

Construct an SPI device attached to a particular module

Parameters

spiModule	The module this device is attached to
chipSelect	The chip select pin used by this device
chipSelectMode	The ChipSelectMode to use with this device
speedMhz	The speed to operate this device at
mode	The SpiMode of this device

Member Function Documentation

SendReceiveAsync()

Task<byte[]> SendReceiveAsync	(	byte []	dataToSend,
		SpiBurstMode	burst = SpiBurstMode.NoBurst
	)

Start an SPI transaction

Parameters

dataToSend	The data to send
burst	The burst mode, if any, to use

Returns

Data received by the peripheral

Property Documentation

ChipSelect

SpiChipSelectPin ChipSelect

getprotected set

Get or set the pin to use for chip-select duties.

Almost every SPI peripheral chip has some sort of chip select (which may be called load, strobe, or enable, depending on the type of chip). You can use any Pin for chip-select duties as long as it belongs to the same board as this SPI peripheral (i.e., you can't use a pin from one Treehopper as a chip-select for the SPI port on another Treehopper). Chip-selects are controlled at the firmware, not peripheral, level, which offers quite a bit of flexibility in choosing the behavior. Make sure to set ChipSelectMode properly for your device.

Mode

SpiMode Mode

getprotected set

Get or set the SPI module's mode

The SPI module supports the four SPI modes: 00, 01, 10, 11. See SpiMode for more info.

Frequency

double Frequency

getset

Gets or sets the Frequency, in MHz, that this device will use for SPI communication.

The SPI module can operate from 0.09375 MHz (93.75 kHz) to 24 MHz. Setting Frequency outside of those limits will result in clipping, plus a debug notice. Note that SPI transfers are managed by the CPU, as Treehopper's MCU has no DMA. As a result, there are diminishing performance returns above 8 MHz, as dead space starts appearing between bytes as the SPI module waits for the CPU to push the next byte into the register.

ChipSelectMode

ChipSelectMode ChipSelectMode

getprotected set

The chip select mode to use with transactions

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The documentation for this class was generated from the following file:

• F:/Git/treehopper-sdk/NET/API/Treehopper.Libraries/SpiDevice.cs