Flightlevel: micropython

Note

This section explains:

  • How to execute micropython code on the MCU.

  • How to read results from the MCU.

  • How to render micropython code using jinja to make it portable between processor families.

Required knowhow:

File: tests/test_simple.py

 1 def test_i2c(
 2     mcu: Tentacle,
 3     device_potpourry: Tentacle,
 4     daq_saleae: Tentacle,
 5 ) -> None:
 6     mp_program = """
 7     from machine import Pin, I2C
 8
 9     {{mcu_config.i2c}}
10
11     pin_trigger_1 = Pin('{{mcu_config.trig1}}', mode=Pin.OUT, value=0)
12     pin_trigger_2 = Pin('{{mcu_config.trig2}}', mode=Pin.OUT, value=0)
13     pin_trigger_1.value(1)
14     i2c_data = i2c.readfrom(0x50, 10, True)
15     pin_trigger_1.value(0)
16     """
17     mcu.dut.mp_remote.exec_render(mp_program, mcu_config=mcu.tentacle_spec.mcu_config)
18
19     i2c_data = mcu.dut.mp_remote.read_bytes("i2c_data")

  • Line 1: test_i2c() is a pytest.

  • Line 6-16: This is micropython code. The {{..}} fragments will be rendered by jinja.

  • Line 11: If mcu_config.trig1=”GP20”, then line will be rendered as pin_trigger_1 = Pin(‘GP20’, mode=Pin.OUT, value=0).

  • Line 17: mcu.dut.mp_remote.exec_render: Execute the micropython code on the dut on the mcu tentacle.

  • Line 17: mcu_config=mcu.tentacle_spec.mcu_config this will instruct jinja to replace {{mcu_config.xyz}} with the values of mcu.tentacle_spec.mcu_config. mcu.tentacle_spec.mcu_config is part of the tentacle specification. You can add new variables to mcu.tentacle_spec.mcu_config when ever needed.

  • Line 28: Read the variable i2c_data from the dut on the mcu tentacle. The expected datatype is bytes.