After reseting the firmware the USB device is not found anymore

#1

My ChipWhisperer-Lite stoped working so I tried to reset its firmware by shorting JP2 while the Lite was on. After shorting the pins, I unplugged and replugged the USB connector and now ,I can see D2 and D9 diodes lit dimly everytime I connect it to my PC.

However the USB is not recognized anymore. When I use the next commands:

import chipwhisperer as cw
scope = cw.scope()

I get the error:

OSError Traceback (most recent call last)
in
1 import chipwhisperer as cw
----> 2 scope = cw.scope()

c:\users\asizu\chipwh~1\git\home\portable\chipwhisperer\software\chipwhisperer_init_.py in scope(scope_type, sn)
226 from chipwhisperer.common.utils.util import get_cw_type
227 if scope_type is None:
–> 228 scope_type = get_cw_type(sn)
229 scope = scope_type()
230 try:

c:\users\asizu\chipwh~1\git\home\portable\chipwhisperer\software\chipwhisperer\common\utils\util.py in get_cw_type(sn)
501 name = “”
502 if len(possible_sn) == 0:
–> 503 raise OSError(“USB Device not found. Did you connect it first?”)
504
505 if (len(possible_sn) > 1):

OSError: USB Device not found. Did you connect it first?

How can I solve this? I tried to uninstall from the device manager and the right drivers for windows are installed also. I have no clue of what is happening.

#2

Hi,

You’ll need to program new firmware onto your Lite before you can connect to it again.

Try the following code:

import chipwhisperer as cw
def program_sam_firmware(hardware_type=None):
    at91_ports = cw.get_at91_ports()
    if len(at91_ports) == 0:
        raise OSError("Could not find bootloader serial port, please see https://chipwhisperer.readthedocs.io/en/latest/firmware.html")
    if len(at91_ports) > 1:
        raise OSError("Found multiple bootloaders, please specify com port. See https://chipwhisperer.readthedocs.io/en/latest/firmware.html")

    serial_port = at91_ports[0]
    print("Found {}".format(serial_port))
    prog = cw.SAMFWLoader(None)
    prog.program(serial_port, hardware_type=hardware_type)

program_sam_firmware("cwlite")

Alex

#3

Hi, thanks for the answer. I tried to run your code, but I got the next error:

AttributeError Traceback (most recent call last)
in
12 prog.program(serial_port, hardware_type=hardware_type)
13
—> 14 program_sam_firmware(“cwlite”)

in program_sam_firmware(hardware_type)
1 import chipwhisperer as cw
2 def program_sam_firmware(hardware_type=None):
----> 3 at91_ports = cw.get_at91_ports()
4 if len(at91_ports) == 0:
5 raise OSError(“Could not find bootloader serial port, please see https://chipwhisperer.readthedocs.io/en/latest/firmware.html”)

AttributeError: module ‘chipwhisperer’ has no attribute ‘get_at91_ports’

#4

Whoops, sorry, that function is on an upcoming update. Try this:

def get_at91_ports():
    from serial.tools import list_ports

    at91_ports = [port.device for port in list_ports.comports() if (port.vid, port.pid) == (0x03EB, 0x6124)]
    return at91_ports

import chipwhisperer as cw
def program_sam_firmware(hardware_type=None):
    at91_ports = get_at91_ports()
    if len(at91_ports) == 0:
        raise OSError("Could not find bootloader serial port, please see https://chipwhisperer.readthedocs.io/en/latest/firmware.html")
    if len(at91_ports) > 1:
        raise OSError("Found multiple bootloaders, please specify com port. See https://chipwhisperer.readthedocs.io/en/latest/firmware.html")

    serial_port = at91_ports[0]
    print("Found {}".format(serial_port))
    prog = cw.SAMFWLoader(None)
    prog.program(serial_port, hardware_type=hardware_type)

program_sam_firmware("cwlite")
#5

It worked! Thank you so much really :slight_smile:

#6

Happy to help :slight_smile:

Alex