Digirig Mobile drops out from USB

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1

I have the Digirig Mobile devices now but am struggling to make them work. For starters, I am connecting to this radio: Amazon.com: Baofeng UV-5R Two Way Radio Dual Band 144-148/420-450Mhz Walkie Talkie 1800mAh Li-ion Battery(Black) : Electronics

If I plug the black cable into the side of the radion the Digirig Mobile fails in some way and removes itself from Linux.

[1034925.892231] usb 1-1.3: new full-speed USB device number 84 using xhci_hcd
[1034925.980611] usb 1-1.3: not running at top speed; connect to a high speed hub
[1034925.981070] usb 1-1.3: New USB device found, idVendor=0424, idProduct=2412, bcdDevice= b.b2
[1034925.981115] usb 1-1.3: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[1034925.984670] hub 1-1.3:1.0: USB hub found
[1034925.984786] hub 1-1.3:1.0: 2 ports detected
[1034926.268212] usb 1-1.3.1: new full-speed USB device number 85 using xhci_hcd
[1034926.359407] usb 1-1.3.1: New USB device found, idVendor=10c4, idProduct=ea60, bcdDevice= 1.00
[1034926.359428] usb 1-1.3.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[1034926.359435] usb 1-1.3.1: Product: CP2102N USB to UART Bridge Controller
[1034926.359440] usb 1-1.3.1: Manufacturer: Silicon Labs
[1034926.359445] usb 1-1.3.1: SerialNumber: fc6053eb33c6ef11af136b527a5e3baa
[1034926.366199] cp210x 1-1.3.1:1.0: cp210x converter detected
[1034926.369223] usb 1-1.3.1: cp210x converter now attached to ttyUSB0
[1034926.447192] usb 1-1.3.2: new full-speed USB device number 86 using xhci_hcd
[1034926.539038] usb 1-1.3.2: New USB device found, idVendor=0d8c, idProduct=0012, bcdDevice= 1.00
[1034926.539059] usb 1-1.3.2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[1034926.539066] usb 1-1.3.2: Product: USB Audio Device
[1034926.539071] usb 1-1.3.2: Manufacturer: C-Media Electronics Inc.
[1034926.562908] input: C-Media Electronics Inc. USB Audio Device as /devices/pci0000:00/0000:00:15.0/usb1/1-1/1-1.3/1-1.3.2/1-1.3.2:1.3/0003:0D8C:0012.0011/input/input29
[1034926.615809] hid-generic 0003:0D8C:0012.0011: input,hidraw1: USB HID v1.00 Device [C-Media Electronics Inc. USB Audio Device] on usb-0000:00:15.0-1.3.2/input3
[1034929.910588] cp210x ttyUSB0: usb_serial_generic_read_bulk_callback - urb stopped: -32
[1034929.912000] cp210x ttyUSB0: usb_serial_generic_read_bulk_callback - urb stopped: -32
[1034930.926668] usb 1-1.3-port2: cannot reset (err = -32)
[1034930.930791] usb 1-1.3-port2: cannot reset (err = -32)
[1034930.931746] usb 1-1.3-port2: cannot reset (err = -32)
[1034930.932524] usb 1-1.3-port2: cannot reset (err = -32)
[1034930.933330] usb 1-1.3-port2: cannot reset (err = -32)
[1034930.933970] usb 1-1.3-port2: Cannot enable. Maybe the USB cable is bad?

If I do not plug the black cable into the side of the radio, this program runs fine and I can watch the RTS line faithfully toggle with programs like “sudo statserial /dev/ttyUSB0”, gtkterm, and others.

$ cat serial-rts-toggle.py 
#!/usr/bin/python

import serial
import time

# Create a standalone connection test loop
ser = serial.Serial('/dev/ttyUSB0', 115200)

print("Toggling RTS every 2 seconds. Check physical voltage or terminal status...")
try:
    while True:
        ser.rts = True
        print("RTS set to HIGH")
        time.sleep(2)
        ser.rts = False
        print("RTS set to LOW")
        time.sleep(2)
except KeyboardInterrupt:
    ser.close()

While using a multi-meter connected between S on both plugs (PTT and GND) I very briefly get continuity when RTS is set to high (not for two seconds).

image
image601Ă—247 35.2 KB

I also tested PTT control on the radio by shorting the inner two pins on the single-plug end of the cable (the end that plugs into the Digirig) and that works as expected.

I can’t think of what I may be doing wrong but will also readily admit that I am outside of my area of expertise here. My hope is that someone will read this and immediately know what I am doing wrong and let me know.

2

Does “removes itself from Linux” happen at the time of transmit, but never before the first attempt? You may be dealing with RFI. This can be addressed by using external antenna with a choked feedline, adding counterpoise, adding additional chokes to the audio cable.

4

Thanks. I think that is my problem.

I put a 10W Dummy Load on the radio in place of its antenna and it doesn’t crash then, but the radio can broadcast less than 50 feet. I used a very long USB cable to get the Digirig+radio away from my USB hub and it still crashes unless I use the 10W Dummy Load, so I think that it is the Digirig crashing from the RFI, not my USB hub/ports.

How do you suggest that I best protect the Digirig Mobile from RFI without having to use a dummy load?

5

the RFI is effecting the usb side so making any usb connections as short as possible and as far away from the transmitting element as possible.
(not just the digirig usb cable)

chokes on the digirig usb cables.
coax, that is also choked, from radio to an antenna located outside the station room.

good luck
:slight_smile:
kb0wlf

1 Like
6

I wanted to follow up to report that I purchased a couple of Digirig Shielded USB Cable with Ferrites and those solved my problem. Using them also revealed to me that I have a few other USB cables in my office that I need to add ferrites to when testing without the 10W Dummy Load installed, so I am off to order a pack of ferrites now.

7

sweet!
kb0wlf