VCP error or bug?

OpenMV Products
1

I’m finding that if I’m using USB_VCP my script runs fine from the ide. However, when I attempt to run the script standalone, it crashes. Other scripts run fine. Is this something I’m doing wrong?

simplified script:

import sensor, image, time, utime
from pyb import LED, USB_VCP 

def blink(led,t=80):
    LED(led).on()
    time.sleep(t)
    LED(led).off() 


def write():
    blink(3,t=1000)
    if usb.isconnected():
        print("usb exists; blinking 2")
        blink(2)
    while(True):
        time.sleep(20)
        if usb.any():
            print("usb exists")
            blink(2, t=1000)
            cmd = usb.readlines(timeout=50) #fails here
        else:
            blink(2,t=50)
            print("Nothing on the usb")

sensor.reset()
sensor.set_pixformat(sensor.GRAYSCALE)
sensor.set_framesize(sensor.QQVGA)
sensor.skip_frames(time = 2000)
sensor.set_auto_gain(False) 
sensor.set_auto_whitebal(False) 
clock = time.clock()
usb = USB_VCP()

while (True):
    write()

output coming from the ide:

>>> usb exists; blinking 2
Nothing on the usb
Nothing on the usb
Nothing on the usb
Nothing on the usb

Output from minicom while running the script:

Welcome to minicom 2.7.1

OPTIONS: I18n 
Compiled on Aug 13 2017, 15:25:34.
Port /dev/ttyACM1, 19:41:01

Press CTRL-A Z for help on special keys             
                                                    
usb exists; blinking 2                              
usb exists                                          
Traceback (most recent call last):                  
  File "/main.py", line 36, in <module>
  File "/main.py", line 21, in write
TypeError: fAT
Traceback (most recent call last):AT
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'AT' isn't defined
>>> ~x~
2

Can you try to communicate to your script using the Open Terminal Feature in OpenMV IDE? It’s under Tools->Open Terminal. It creates a terminal to talk to the camera.

3

Running connecting with the IDE terminal yields an “Exception: IDE interrupt” blocking my script from running still. I have tried adding

usb.setinterrupt(-1)

to no avail.

Additional point I forgot in the first post: if I leave nothing connected to camera I can tell from the blinks it has crashed too.

4

Do you have an H7 or an H7 plus? We just found a serious issue in the H7 firmware in regards to it being overclocked.

5

H7 R1. Can you elaborate at all on this bug? Is there an issue open already for it on github?

Could I push an earlier version of firmware to resolve this potentially?

6

There seems to be a bug in readline and readlines, please avoid using it, for now you can implement something like this:

while (usb.any()):
    print(usb.recv(1, timeout=100))
7

You should report a bug on github to keep track of this issue.