SPI Methods

These methods are not specific to a given spi device but instead allow you to control any spi device by implementing the device's protocol as specified by the manufacturer's datasheet.

set_pin_mode_spi

 def set_pin_mode_spi(self, spi_port=0, miso=16, mosi=19, clock_pin=18,
                         clk_frequency=500000, chip_select_list=None,
                         qualify_pins=True):
        """
        Specify the SPI port, SPI pins, clock frequency and an optional
        list of chip select pins. The SPI port is configured as a "master".
        :param spi_port: 0 = spi0, 1 = spi1
        :param miso: SPI data receive pin
        :param mosi: SPI data transmit pin 
        :param clock_pin: clock pin
        :param clk_frequency: clock frequency in Hz.
        :param chip_select_list: this is a list of pins to be used for
                           chip select. The pins will be configured as output,
                           and set to high ready to be used for chip select.
                           NOTE: You must specify the chips select pins here!

        cammand message: [command, spi port, mosi, miso, clock, freq msb,
                          freq 3, freq 2, freq 1, number of cs pins, cs pins...]


        """

This method must be called before calling any other spi method. You may choose to use the "standard" MOSI, MISO, and Clock pins as listed above.

All chip select pins for the select SPI port are specified when calling this method.

spi_read_blocking

 def spi_read_blocking(self, number_of_bytes, spi_port=0, call_back=None, 
                       repeated_tx_data=0)

    Read the specified number of bytes from the specified SPI port and call 
    the callback function with the reported data.

    :param number_of_bytes: Number of bytes to read

    :param spi_port: SPI port 0 or 1

    :param call_back: Required callback function to report spi data as a result 
                      of read command

    :param repeated_tx_data: repeated data to send

    callback returns a data list:
        [SPI_READ_REPORT, spi_port, count of data bytes, data bytes, time-stamp]

        SPI_READ_REPORT = 13

This method retrieves the requested number of bytes and returns the result within the specified callback method.

The callback argument is not optional and must be specified.

spi_write_blocking

 def spi_write_blocking(self, bytes_to_write, spi_port=0)

    Write a list of bytes to the SPI device.

    :param bytes_to_write: A list of bytes to write. This must be in the form of a list.

    :param spi_port: SPI port 0 or 1

This method writes a list of bytes to the specified SPI port.

Example: spi_bme280.py

Copyright (C) 2022 Alan Yorinks. All Rights Reserved.