Thought I’d share a pleasant little discovery I made this afternoon…it dawned on me that one or more USB headsets roaming about in the wild likely have CM108 or CM119 chipsets, and that with a little tinkering, one might just fit the bill for a radio-less setup. Having a seasoned career in VoIP (and with Asterisk, no less), I decided to rummage through my box of USB headsets, just to see what works. I had a few different Plantronics and Sennheiser models, a couple of Logitech models, and some other oddities…nothing panned out. Finally, I pulled out an old tried and true favorite, the Mpow 071.
The Mpow 071 is a budget headset, and runs anywhere from $25-$35 USD (pending on where you go to find one), but it has some cushy ear pads with integrated volume controls and decent audio response. It’s related to the Mpow 224, which is the slightly bigger brother with a little larger earphones. Both of which are reputable headsets for the money; they have good audio fidelity and a little noise cancelling.
I plugged the 071 in to a Raspberry Pi 3B+, fiddled with SimpleUSB configuration, set audio levels, set rxboost to true, and had an audio path if I manually keyed COR in the SimpleUSB menu. Now, to simulate PTT…hmm…what to do? Well, as luck would have it, I decided to press the buttons on the integrated audio controls to find the volume down (-) simulates COR logic if held in, so long as usbinvert is set to true. So, there you have it, a headset with PTT…success!
Audio levels seem OK if you have decent hearing; if you have difficulty, maxing out the range won’t get you incredibly far, but it should fit the bill for most people. Otherwise, with just a Raspberry Pi and Mpow 071, you can take this setup on the go. DTMF command shortcomings can be solved using AllMon or entering commands across the Asterisk CLI if you have a computer nearby. While this may not be the most graceful or robust option, it’s certainly an inexpensive one that requires no hardware modifications and can come in incredibly handy if you stay tethered to one node regularly.
That excites me way more than a headset…I can’t wait! I’ll definitely be among your first orders for that, no question. Let us know when the technical specifications and documentation come out, would you?
I’m trying to look up the pinout of the DB-9 connector – I can’t seem to find it anywhere for any of the RA- products. Can you link me? I wish I would have known about your product before soldering a bunch of CM108s. (failing twice)
You really ought to add those to the Allstar Wiki so it’s front and center.
According to their web site the DB9 matches the Kantronics connector pinouts, this seems to be a standard for a lot of other manufacturers as well such as the APRS TinyTrac device and the Argent Data opentrackers.
I’m trying to look up the pinout of the DB-9 connector – I can’t seem to find it anywhere for any of the RA- products. Can you link me? I wish I would have known about your product before soldering a bunch of CM108s. (failing twice)
You really ought to add those to the Allstar Wiki so it’s front and center.
That is incorrect. DRA adapters vary from RA (and RL) adapters in terms of pinouts. This is why it’s important people read the documentation on the website; everything is clearly documented there.
From: Rob via AllStarLink Discussion Groups [mailto:noreply@community.allstarlink.org] Sent: Monday, July 06, 2020 11:10 PM To:ke6pcv@cal-net.org Subject: [AllStarLink Discussion Groups] [App_rpt-users] An inexpensive radio-less setup–just add a USB headset!
I’m trying to look up the pinout of the DB-9 connector – I can’t seem to find it anywhere for any of the RA- products. Can you link me? I wish I would have known about your product before soldering a bunch of CM108s. (failing twice)
You really ought to add those to the Allstar Wiki so it’s front and center.
That excites me way more than a headset…I can’t wait! I’ll definitely be among your first orders for that, no question. Let us know when the technical specifications and documentation come out, would you?
I am looking to setup ASL with a usb headset. I’ve now bought 3 of the Mpow 071 headsets with the usb adapter supplied. All 3 appears as:
dmesg
[759867.353254] usb 3-2: New USB device found, idVendor=0d8c, idProduct=0014, bcdDevice= 1.00
[759867.353257] usb 3-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[759867.353258] usb 3-2: Product: Mpow HC
[759867.353259] usb 3-2: Manufacturer: C-Media Electronics Inc.
[759867.353259] usb 3-2: SerialNumber: 20170817
[759867.363502] input: C-Media Electronics Inc. Mpow HC as /devices/pci0000:00/0000:00:14.0/usb3/3-2/3-2:1.3/0003:0D8C:0014.000A/input/input21
[759867.420784] hid-generic 0003:0D8C:0014.000A: input,hidraw2: USB HID v1.00 Device [C-Media Electronics Inc. Mpow HC] on usb-0000:00:14.0-2/input3
lsusb
Bus 003 Device 015: ID 0d8c:0014 C-Media Electronics, Inc.
which is not listing as a cm108.
Is there anyway to recompile ASL from source to match this device as an alternative to the cm108 ?
Ordered the MPOW, got it in, plugged in to an existing node, pushed the - button and IT WORKED. (Did have to adjust volume up to 800 out of 999) to get a good TX… Thanks!!!
Well after researching what the heck a MPOW device is…I need to ask what was the actual brand and model number of the device you purchased that worked so easily.
@Forking_Pork If you still have your MPOW 071 would you mind giving the output of lsusb? Mine is showing as a Unitek Y-247A and I have not been able to get it working with ASL. It works out of the box with a HamVOIP image, but my goal is to run ASL in a VM with USB passthrough.
This is how my MPOW 071 is reading with lsusb:
Bus 001 Device 007: ID 0d8c:0014 C-Media Electronics, Inc. Audio Adapter (Unitek Y-247A)
