Kevin, Thanks for the response. Caught you on the hamvoip list as well. So the primary question of this post still stands. Is there a way to tell ASL to receive audio from my microphone without the COS signal? Maybe a change of direction. Can I pull discriminator audio from the UV82 and use usbradio instead of simpleusb? If I can't get it to work this way with the UV82, I do have some GM300s I may be able to use with de-emphasized audio. I am still in the very beginning stages of learning how all of this gets put together, so if I use some incorrect terminology, please forgive me. These lists have been very helpful! Thanks, James On Thu, May 2, 2019 at 4:45 PM Kevin Custer <kuggie@kuggie.com> wrote:
James,
From your description, and my extensive knowledge of the CM119, CM119A and its variants, I believe the chip is bad. You can try to add a 10k pull-up externally to 3.3V from pin 48, but I doubt it'll work. Hopefully you are using protection diodes on these hardware inputs, otherwise, that's what blew it up. Why? Here's why....
There is much confusion surrounding the COS and CTCSS inputs to the CM1XX chipsets. Here is a dissertation I wrote some time ago, that hopefully explains the situation well:
The COS and PL "hardware" logic inputs on CM1XX based radio adapters were originally the volume-up and volume-down functions, actuated by manual (push button tactile) switches in a standard audio adapter (FOB). These inputs are internally pulled high, to 3.3 V, and have to be pulled low enough to become valid. As such the push-button switches made a good ground when depressed, as that's what the other side of the switch was tied to - ground. Most AllStar radio adapters use protection diodes (BAT-43's) that don't allow voltage to be sent into the CM1XX chip. If voltage is allowed to be inputted to these pins, the chip is destroyed. So - with the diodes in place, it doesn't matter what voltage is present on the COS or CTCSS hardware inputs, because voltage on these pins doesn't make anything happen, and because of the protection diodes, doesn't hurt anything if voltage is present. Pull-up resistors are totally unnecessary, because we need a ground to assert the condition.
Okay, so the CM108/119's logic inputs are looking for a ground to be valid. This "active low" condition is required NO MATTER if the setting in the conf file is upright or inverted. So - the setting in the configuration file doesn't change the fact that the adapter needs an active low to be valid and assert the condition. All this software setting does is change if the low condition exists when the radio is hearing a valid signal, or when it's not. Using a DMM, you can read the voltage on the CM119 side of the BAT-43 diodes to see if the logic level is properly changing from 3.3V (2.4 in some instances) to 0.0 (or a few tenths of a volt).
Not all radio logic signals are created equal. Some logic circuits can source current, but lack the ability to sink. Sometimes active high circuits (circuits that provide a voltage when the state becomes active) don't have the ability to pull to ground very well. These circuits may not have the capability to pull the COS and CTCSS inputs low enough on the radio adapter to become valid/active. A pull-down resistor can help, but nothing beats a real active low circuit. A 2N2222 (or similar NPN transistor) with the emitter grounded usually works well.
Hope this helps...
Kevin
On 5/2/2019 4:07 PM, James WD0JB wrote:
All,
Is there a way to manually key from the Asterisk command-line, or other, to transmit when using a USB fob without the COS activated? I have a fob that I cannot key with pin48 on CM119, but I still want to use the fob, possibly as a radio-less node with a headset / microphone. I cannot key with pin48 on the CM119 because there is not the proper voltage on that pin to pull down.
If anyone has any suggestions, I am using the SYBA UAUD compact fob. This Amazon link: https://www.amazon.com/dp/B001MSS6CS
Also, these fobs (I've tried 2 so far) have an eeprom chip on them (FT93C46A). Any others I've seen used in this manner from forum posts do not appear to have this chip, however, removing the chip does not resolve the issue. One fob has 200mv the other has about 1volt. Nothing else connected to the pin.
Thanks in advance for any help.
James
-- 73, James WD0JB