NeXT
Veteran Member
One thing that's nice about radio is that you can talk whenever you want but you have to press a button down or key in to actually speak. Unless you have some fancy hardware already this can be a bit more tricky for voice chats even though they already have the provision for selecting from multiple audio inputs and defining a physical key to enable/disable your microphone. That and I've also not spent more than ten minutes looking to see what could be found for under $20.
I have seen a few iterations on this before in a more professional manner but typically they were restricted to a specific software package or worse, it needed a driver so it wasn't really a Universal Plug and Play solution. This got me thinking about how I could solve this myself without getting super fancy and that's how I came up with this idea.
What if we took the microphone and combined into it both the USB audio input and the keyboard? If the software did not support PTT it still acted as just a microphone with a physical switch to cut the mic feed off but if it supported PTT and mapping the talk button to a key it's all combined. Plus there's now a plethora of generic input drivers that mean we can do this without having to write or supply drivers. You just gotta make it all fit into the microphone.
This is our test subject. An Astatic tabletop paging microphone. Typically found for $80 to $120 online. I have four or five of them that came out of The Hackery for $5 total and have been converting them to the DIN plugs on my CB radio base stations. Looks presentable, Has a simple microphone and the pushbutton for talking that can be latched down if necessary. It has a leaf switch inside that has two contacts. One that closes before the other. This is handy so that when you push to talk the mic contact closes before the actual PTT signal is sent and the receiving end doesn't hear the "pop" as the mic goes live.
Here's the other bits I'll need. A crummy USB numpad, one of those awful USB audio dongles and a cheap USB hub. All total E-waste in their own right but they all have something in common: They are small.
We need to strip all the connectors and cables off everything to make this fit but then we only need to deal with thin strips of circuit board to route wiring over. For the USB keypad we can strip nearly everything away and leave ourselves with the board as well. At this point however I need to select what key will be our hardwired PTT signal. I selected numpad "0".
Some of the stripped parts will get reused as handy repairs later. Broken headphone jack? Boom, done. Broken USB port on the front of your PC? Easy.
The base is weighted, but still gives roughly a quarter inch of space inside the housing for extra bits. This means we can both remove the weight to attach the boards using sticky pads but also wire it all together and still have room inside for cables to fold and tuck away as to not interfere with the controls. At this point you get to play the game of USB Pinouts where some devices have the pin designation silkscreened on, some don't and others have them out-of-order.
Likewise you get to find out if whoever assembled these previous used the correct color coding and if you can use them as hints. Eventually though you should be able to stick everything down and hardwire both the keypad and the audio into the hub. As I was doing this I was plugging and unplugging the USB cable into an isolated USB port on my computer to verify things were getting power and being properly detected and if I made a mistake hopefully it was only the device that went poof and not the hub controller in my PC.
Once I was confident all the hardware worked I ran a lead from the keypad header down to the second of the two leaf switches (PTT) and routed one leg of the microphone through the first leaf switch (microphone cut). Then I replaced the cheesy thin USB cable I was using for testing with a more appropriate and thicker beige cable and screwed the entire thing together into a nice and self-contained unit.
So here's how it works:
You take the microphone and pug it into damn-near anything. It sees and sets up the hub, then it can see and setup the keypad and the audio device. You open your application of choice, select the audio dongle as your input and then map the key you chose for your PTT switch. From there you're good to go.
Now in practice did it work? Kind of?
Part of this I'm blaming on the use of the cheapest parts imaginable but that means they can be upgraded later to fix this since I've proven that it did, in fact work. The microphone wasn't as sensitive as I wished it could of been and since I was now using a mechanical switch rather than a membrane contact the keybounce routine was a little confused and sometimes PTT acted up. Otherwise yes, it works fine and looks presentable. I do intend to now go back and fix the minor audio and control issues but now I have something I can drop on a table, plug in and we have a keyed mic with software PTT control.
I have seen a few iterations on this before in a more professional manner but typically they were restricted to a specific software package or worse, it needed a driver so it wasn't really a Universal Plug and Play solution. This got me thinking about how I could solve this myself without getting super fancy and that's how I came up with this idea.
What if we took the microphone and combined into it both the USB audio input and the keyboard? If the software did not support PTT it still acted as just a microphone with a physical switch to cut the mic feed off but if it supported PTT and mapping the talk button to a key it's all combined. Plus there's now a plethora of generic input drivers that mean we can do this without having to write or supply drivers. You just gotta make it all fit into the microphone.
This is our test subject. An Astatic tabletop paging microphone. Typically found for $80 to $120 online. I have four or five of them that came out of The Hackery for $5 total and have been converting them to the DIN plugs on my CB radio base stations. Looks presentable, Has a simple microphone and the pushbutton for talking that can be latched down if necessary. It has a leaf switch inside that has two contacts. One that closes before the other. This is handy so that when you push to talk the mic contact closes before the actual PTT signal is sent and the receiving end doesn't hear the "pop" as the mic goes live.
Here's the other bits I'll need. A crummy USB numpad, one of those awful USB audio dongles and a cheap USB hub. All total E-waste in their own right but they all have something in common: They are small.
We need to strip all the connectors and cables off everything to make this fit but then we only need to deal with thin strips of circuit board to route wiring over. For the USB keypad we can strip nearly everything away and leave ourselves with the board as well. At this point however I need to select what key will be our hardwired PTT signal. I selected numpad "0".
Some of the stripped parts will get reused as handy repairs later. Broken headphone jack? Boom, done. Broken USB port on the front of your PC? Easy.
The base is weighted, but still gives roughly a quarter inch of space inside the housing for extra bits. This means we can both remove the weight to attach the boards using sticky pads but also wire it all together and still have room inside for cables to fold and tuck away as to not interfere with the controls. At this point you get to play the game of USB Pinouts where some devices have the pin designation silkscreened on, some don't and others have them out-of-order.
Likewise you get to find out if whoever assembled these previous used the correct color coding and if you can use them as hints. Eventually though you should be able to stick everything down and hardwire both the keypad and the audio into the hub. As I was doing this I was plugging and unplugging the USB cable into an isolated USB port on my computer to verify things were getting power and being properly detected and if I made a mistake hopefully it was only the device that went poof and not the hub controller in my PC.
Once I was confident all the hardware worked I ran a lead from the keypad header down to the second of the two leaf switches (PTT) and routed one leg of the microphone through the first leaf switch (microphone cut). Then I replaced the cheesy thin USB cable I was using for testing with a more appropriate and thicker beige cable and screwed the entire thing together into a nice and self-contained unit.
So here's how it works:
You take the microphone and pug it into damn-near anything. It sees and sets up the hub, then it can see and setup the keypad and the audio device. You open your application of choice, select the audio dongle as your input and then map the key you chose for your PTT switch. From there you're good to go.
Now in practice did it work? Kind of?
Part of this I'm blaming on the use of the cheapest parts imaginable but that means they can be upgraded later to fix this since I've proven that it did, in fact work. The microphone wasn't as sensitive as I wished it could of been and since I was now using a mechanical switch rather than a membrane contact the keybounce routine was a little confused and sometimes PTT acted up. Otherwise yes, it works fine and looks presentable. I do intend to now go back and fix the minor audio and control issues but now I have something I can drop on a table, plug in and we have a keyed mic with software PTT control.
