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import os
import sys
import periphery
from .test import ptest, pokay, passert, AssertRaises
if sys.version_info[0] == 3:
raw_input = input
spi_device = None
def test_arguments():
ptest()
# Invalid mode
with AssertRaises("invalid mode", ValueError):
periphery.SPI("/dev/spidev0.0", 4, int(1e6))
# Invalid bit order
with AssertRaises("invalid bit order", ValueError):
periphery.SPI("/dev/spidev0.0", 4, int(1e6), bit_order="blah")
def test_open_close():
ptest()
# Normal open (mode=1, max_speed = 100000)
spi = periphery.SPI(spi_device, 1, 100000)
# Confirm fd and defaults
passert("fd > 0", spi.fd > 0)
passert("mode is 1", spi.mode == 1)
passert("max speed is 100000", spi.max_speed == 100000)
passert("default bit_order is msb", spi.bit_order == "msb")
passert("default bits_per_word is 8", spi.bits_per_word == 8)
# Not going to try different bit order or bits per word, because not
# all SPI controllers support them
# Try modes 0, 1, 2, 3
spi.mode = 0
passert("spi mode is 0", spi.mode == 0)
spi.mode = 1
passert("spi mode is 1", spi.mode == 1)
spi.mode = 2
passert("spi mode is 2", spi.mode == 2)
spi.mode = 3
passert("spi mode is 3", spi.mode == 3)
# Try max speeds 100Khz, 500KHz, 1MHz, 2MHz
spi.max_speed = 100000
passert("max speed is 100KHz", spi.max_speed == 100000)
spi.max_speed = 500000
passert("max speed is 500KHz", spi.max_speed == 500000)
spi.max_speed = 1000000
passert("max speed is 1MHz", spi.max_speed == 1000000)
spi.max_speed = 2e6
passert("max speed is 2MHz", spi.max_speed == 2000000)
spi.close()
def test_loopback():
ptest()
spi = periphery.SPI(spi_device, 0, 100000)
# Try list transfer
buf_in = list(range(256)) * 4
buf_out = spi.transfer(buf_in)
passert("compare readback", buf_out == buf_in)
# Try bytearray transfer
buf_in = bytearray(buf_in)
buf_out = spi.transfer(buf_in)
passert("compare readback", buf_out == buf_in)
# Try bytes transfer
buf_in = bytes(bytearray(buf_in))
buf_out = spi.transfer(buf_in)
passert("compare readback", buf_out == buf_in)
spi.close()
def test_interactive():
ptest()
spi = periphery.SPI(spi_device, 0, 100000)
print("Starting interactive test. Get out your logic analyzer, buddy!")
raw_input("Press enter to continue...")
# Check tostring
print("SPI description: {}".format(str(spi)))
passert("interactive success", raw_input("SPI description looks ok? y/n ") == "y")
# Mode 0 transfer
raw_input("Press enter to start transfer...")
spi.transfer([0x55, 0xaa, 0x0f, 0xf0])
print("SPI data 0x55, 0xaa, 0x0f, 0xf0")
passert("interactive success", raw_input("SPI transfer speed <= 100KHz, mode 0 occurred? y/n ") == "y")
# Mode 1 transfer
spi.mode = 1
raw_input("Press enter to start transfer...")
spi.transfer([0x55, 0xaa, 0x0f, 0xf0])
print("SPI data 0x55, 0xaa, 0x0f, 0xf0")
passert("interactive success", raw_input("SPI transfer speed <= 100KHz, mode 1 occurred? y/n ") == "y")
# Mode 2 transfer
spi.mode = 2
raw_input("Press enter to start transfer...")
spi.transfer([0x55, 0xaa, 0x0f, 0xf0])
print("SPI data 0x55, 0xaa, 0x0f, 0xf0")
passert("interactive success", raw_input("SPI transfer speed <= 100KHz, mode 2 occurred? y/n ") == "y")
# Mode 3 transfer
spi.mode = 3
raw_input("Press enter to start transfer...")
spi.transfer([0x55, 0xaa, 0x0f, 0xf0])
print("SPI data 0x55, 0xaa, 0x0f, 0xf0")
passert("interactive success", raw_input("SPI transfer speed <= 100KHz, mode 3 occurred? y/n ") == "y")
spi.mode = 0
# 500KHz transfer
spi.max_speed = 500000
raw_input("Press enter to start transfer...")
spi.transfer([0x55, 0xaa, 0x0f, 0xf0])
print("SPI data 0x55, 0xaa, 0x0f, 0xf0")
passert("interactive success", raw_input("SPI transfer speed <= 500KHz, mode 0 occurred? y/n ") == "y")
# 1MHz transfer
spi.max_speed = 1000000
raw_input("Press enter to start transfer...")
spi.transfer([0x55, 0xaa, 0x0f, 0xf0])
print("SPI data 0x55, 0xaa, 0x0f, 0xf0")
passert("interactive success", raw_input("SPI transfer speed <= 1MHz, mode 0 occurred? y/n ") == "y")
spi.close()
if __name__ == "__main__":
if os.environ.get("CI") == "true":
test_arguments()
sys.exit(0)
if len(sys.argv) < 2:
print("Usage: python -m tests.test_spi <SPI device>")
print("")
print("[1/4] Arguments test: No requirements.")
print("[2/4] Open/close test: SPI device should be real.")
print("[3/4] Loopback test: SPI MISO and MOSI should be connected with a wire.")
print("[4/4] Interactive test: SPI MOSI, CLK, CS should be observed with an oscilloscope or logic analyzer.")
print("")
print("Hint: for Raspberry Pi 3, enable SPI0 with:")
print(" $ echo \"dtparam=spi=on\" | sudo tee -a /boot/config.txt")
print(" $ sudo reboot")
print("Use pins SPI0 MOSI (header pin 19), SPI0 MISO (header pin 21), SPI0 SCLK (header pin 23),")
print("connect a loopback between MOSI and MISO, and run this test with:")
print(" python -m tests.test_spi /dev/spidev0.0")
print("")
sys.exit(1)
spi_device = sys.argv[1]
test_arguments()
pokay("Arguments test passed.")
test_open_close()
pokay("Open/close test passed.")
test_loopback()
pokay("Loopback test passed.")
test_interactive()
pokay("Interactive test passed.")
pokay("All tests passed!")
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