Change baud rade in embedded-serial service (RDT-227)

[KaDw]

Hi,

Cool project, especially for integration testing on embedded systems.
I'm just checking it out but I'm not that familiar with python. How do I configure the baud rate for embedded-serial service?

[hfudev]

Hi @KaDw ! Now you can use the environment variable ESPBAUD to specify it. Would improve the cli arguments in the future :) (#96)

[KaDw]

Thanks for the fast response! I will check this out

One more question, I'm using Windows 10 with FT232 and CP210x UART-USB converter.

At first I tried to use one serial converter with RX and TX shorted.
On the software side I'm basically using the echo example with slight modifications: I removed the conftest.py and modified test script as following:

import pytest

@pytest.mark.parametrize(
    'port',
    ['COM12'],
    indirect=True,
)
def test_echo_tcp(dut):
    dut.write(b'aaa')
    dut.expect('aaa')  # will decode automatically

This didn't work, pexpect.expectations.TIMEOUT: Not found "aaa"

Next just to make sure that it is not fault on the hardware side I prepared following setup:

         RX <- TX    
COM7 <-> TX -> RX    <-> COM12
         GND <-> GND

The software side is the same.
I checked that I can see in COM12 everything that I type in COM7 and the other way
Then every second I send 'a' character to COM7 which is received at COM12 (this is the DUT)

In both cases all I get is:

pexpect.expectations.TIMEOUT: Not found "aaa"
Bytes in curent buffer:
Please check the full lof here C:/Users/ ...

However, in COM7 I can see aaa so the dut.write executed correctly.

Any ideas what I might try to make the dut.expect (the RX side) work?

[hfudev]

Unaware of why the first try failed, but for your second example,
this line you're writing dut.write('aaa') is actually writing to the COM12 port, since the dut is using the port in your param.

This is a multi dut case, you may try this code block

import pytest

@pytest.mark.parametrize(
    'count, port',
    [(2, 'COM7|COM12')],
    indirect=True,
)
def test_echo_tcp(dut):
    com7 = dut[0] 
    com12 = dut[1]
    com7.write('aaa')
    com12.expect('aaa')  # will decode automatically

related docs: https://docs.espressif.com/projects/pytest-embedded/en/latest/key_concepts/#multi-duts

[KaDw]

Good to know that the framework supports multiple duts!

About the second test. I'm writing using dut.write('aaa') to COM12 and see the output on COM7. This is not intended to be multi dut case but a case where I can see if the write method works fine. I ended up manually pushing 'a' key over 30 seconds to make sure that the other side (COM12) can receive the characters.

I'm just trying to figure out why I can't receive anyting using expect() method and the buffer is empty. That's why I'm doing such weird things :P

Just to be on the same side: My problem is that I can write to the COM portbut I'm unable to receive anything (may be I should open another issue about that)

PS. I made small mistake in my last comment, I'm using dut.write (b'aaa') not dut.write ('aaa')

[hfudev]

dut.write (b'aaa') and dut.write ('aaa') should be the same.

may be I should open another issue about that

sure. that would be better.

In the new issue, you may also attach a few additional info, like:

1. the cli command and the output
2. does it work with interacting with the port directly, without pytest-embedded? For example, can you receive bytes if using putty to send the characters?
3. pip list | grep pytest-embedded

and back to this issue, does the ESPBAUD workaround work? if it works you may close this issue and open the new one :)

[KaDw]

The ESPBAUD workaround does not work.

I'm using Windows 10 and set the environmental variable in System variables (I also tried to set the env variable using set ESPBAUD=921600). I can see that it is set to correct value, echo %ESPBAUD% gives me 921600. When I call pytest the dut.write still uses 115200. I just used another usb-uart to montor the output of COM12 with 115200 and regardless of ESPBAUD I can only see correct characters when it is set to 115200.

I created new issue about the problem with dut.expect() - #97

[igrr]

@hfudev i think that's probably because ESPBAUD is only taken into account in pytest-embedded-serial-esp for flashing, but not used in pytest-embedded-serial for the actual data exchange over serial (not that it's supposed to be used there...)

[igrr]

Maybe patching the value in Serial class can be a workaround for the time being. For example, in conftest.py:

from pytest_embedded_serial.serial import Serial as ESerial
ESerial.DEFAULT_PORT_CONFIG['baudrate']=921600

[KaDw]

@igrr Thanks, this workaround works!