This is a outline of the basic hardware required to get the OpenRepeater system up and running. It will require some skills and understanding on your part to put all the pieces together into a working system. Some Linux and Basic Electronics know-how is a must.
The SBC (Single Board Computer)
First thing that you'll need is a single board computer to run the OpenRepeater system software. In our testing we are currently supporting the following boards: Raspberry Pi 2/3. Please follow the Getting Started Guide for Software
to download and install the ready made IMG files on to your device.
The Basic Hardware Interface
The next step is to be able to interface the RX and TX radios to the SBC. We are currently working on a hardware interface design, but in the meantime an Easy Digi and USB sound card should do the trick. Above is a basic diagram of how this should be wired.
Not shown above would be any addition circuitry such as any attenuation resistors to get the audio at the right level and optionally another optocoupler circuit to handle the COS control as the software VOX is a little sketchy right now and is not an ideal solution anyways. Below is an example of what the COS circuit would look like with an optocoupler in a pull up configuration. VCC should go to 3.3 volt pin (NOT 5 volt pin as you could damage your GPIO pin). Ground should go to GPIO ground pin. Input pin will go to the GPIO pin that you assigned to the COS in the web control panel. You will need to provide the appropriate circuitry on the LED side for your needs. Note that The GPIO pin number is different than the actual pin number on the header. 10K should be a good value for the resister.
The Future Hardware Interface
Our plans are to design a compact interface board that could likely mount onto the GPIO header of the chosen SBC. Some of the features we are planning to include are:
- Integrated Sound (not USB)
- TX and RX audio isolation from sound card and radios
- Opto-Isolated COS and PTT control
- Optional Real Time Clock for "off-grid" setups
- Secondary port ideal for link radio
- Integrated voltage regulator to allow the system to run off of 12v/13.8v instead of 5v.
Where to Purchase
Available from: CliffordWareHam (eBay Seller)