spimaster

SPI Master

Communicate via SPI with an ESP8266 module.

The Micropython board is the SPI master and the ESP8266 the slave. The HSPI port of the ESP822 is used, which is implemented in hardware and controlled by an Arduino-for-ESP8266 sketch, which uses the SPISlave library.

To test, wire the two boards together like this:

Function	Pyboard / STM32F4DISC	ESP8266 / NodeMCU
SS	X5 / (P)A4	15 / D8
SCK	X6 / (P)A5	14 / D5
MISO	X7 / (P)A6	12 / D6
MOSI	X8 / (P)A7	11 / D7
GND	GND	GND

On the ESP8266 use the Arduino IDE to compile & upload the "SPISlave/SPISlave_Test.ino" sketch from the examples included with the Arduino core for ESP8266.

You can test and benchmark the communication on your micropython board with the following code:

import pyb
from time import ticks_diff, ticks_ms
from spimaster import SpiMaster

def timeit():
    spi = SpiMaster(1, baudrate=int(pyb.freq()[3] / 16))
    start = ticks_ms()

    for i in range(2 ** 10):
        spi.write_data(b'abcdefgh' * 4)
        spi.read_data()

    print("Millisecond ticks elapsed: %i" % ticks_diff(ticks_ms(), start))

timeit()