The Easy Digi boards are a great kit for those who want an easy project. I've done a couple other posts about them and if you want more details click here and here.
|1st Easy Digi Interface|
This time the goal is simplicity. I needed to create an interface that has one USB connection to the PC and a modular plug for connecting to a transceiver. That means I have to cram all the components into a box and try to keep it compact enough you can easily throw it into your go bag.
You need three major components to make this interface work. You need the Easy Digi circuit, a serial device to trigger the PTT, and a sound device. Fortunately today all of these components are relatively cheap and easy to get.
For this project I picked up (Total $38.83) :
- Easy Digi Interface Kit ($12.55)
- USB to DB9 Serial module ($5.95)
- USB Sound Card ($5.28)
- 4 Port USB Hub ($1.98)
- CAT5e RJ45 M/F Panel Mount ($5.95)
- ABS Plastic Project Box 3.5 x 3.5 x 2.24 inch ($7.12)
|Easy Digi Assembled|
The first step is to put the Easy Digi kit together. I won't go into detail for that here, the instructions with the kit are very easy to follow.
After that I started taking plastic cases off all the stuff I ordered so everything would fit in the project box. Luckly the enclosures were all just fitted together and not glued, so they just pulled apart.
|USB Sound Device|
|USB Sound Device with case removed|
Next I needed to attach the USB serial device that controls the PTT circuit. There needs to be a connection from the DTR, RTS, and ground pins on the serial device to the corresponding solder pads on the EasyDigi board. Note that when looking for a USB serial device, you need one that presents the correct voltages. I've found that usually the adapters that actually have a DB9 connector on them provide the 5+ volts necessary to operate the optocoupler for the PTT. Don't bother trying to use the cheap UART devices.
|RJ45 Panel Mount|
|RJ45 Panel Mount wires exposed|
|RJ45 Panel Mount wired to Easy Digi|
After that, I needed to install the RJ45 panel mount that will connect the device to the radio. I chopped the plug end of the panel mount cable off and wired it to the board using the following pinout. This assumes the panel mount is wired as a T-568B standard, starting with the orange/white, orange wires.
PIN Color Function
1 Orange/White RX Audio
2 Orange RX Audio
3 Green/White MIC In
4 Blue MIC Ground
5 Blue/White PTT High
6 Green PTT Ground
7 Brown/White Not Connected
8 Brown Not Connected
|Windows Installing New Devices|
|Device Manager showing new devices|
|Install Old Prolific Driver if needed.|
Running the UZ7HO soundmodem software and Winlink Express, I test my connection using the interface. Once I'm sure the components are working correctly, I installed them in the project box.
|Inside a finished Super Easy Digi|
To route the cables out of the box. I used a rotary tool to cut a notch in two of the sides of the box. One for the USB hub cable to come out and one for the RJ45 jack. Luckily the USB hub cable has a molded strain relief still attached and I was able to reuse it with the box. The RJ45 jack is held in place by the lip of the enclosure. It pinches the cable enough that it takes quite a lot of force to either pull it out or push it into the box.
|Complete Super Easy Digi|
I hope you enjoyed this project! 73