NW Digital Radio Blog page 8

Adding a Display to AMBEServer

An AMBEServer provides a great platform for supporting applications like DummyRepeater, which need a platform to convert audio to AMBE and back again.

In previous blog posts we have discussed using the AMBEServer with DummyRepeater, but have always used a display on another computer or HDMI monitor to accomplish this task.

I decided I would like to see if I could get a Raspberry Pi display attached to an AMBEServer for user interaction without the need for a remote computer display or HDMI connected monitor.

I decided to try the Adafruit Pi TFT as a display.  Here are the early results.  After receiving the PiTFT, I followed the assembly instructions and software install instructions. I used the deb file method rather than loading a new image.

The display came right up.  Here are the results.

adafruit-tft-crop

DummyRepeater display on PiTFT

 

Stacked DV3000 and PiTFT on Raspberry Pi

Stacked DV3000 and PiTFT on Raspberry Pi

 

End view of DV3000 and PiTFT on Raspberry Pi -- Need supports

End view of DV3000 and PiTFT on Raspberry Pi 

 

As you can see this all stacks up nicely, I just need to come up with a support and a case to hold it all!

The current UI isn’t optimized for the 320×240 display yet, but as you can see the touch PTT/Transmit button is clearly visible and the TFT touch function of the board works.  The board also supports 4 buttons that UI designers could use for a menu operated or similar system.  Additionally, adding a USB or Bluetooth keyboard and mouse are supported.

 

DV3000 in Japan – Portable DummyRepeater

Note from our new friend Satoru, JA1SCW, on Olive Island in Japan
PortableDR

Portable DummyRepeater

Since I started D-Star about two years ago, I have been looking for a solution for a portable rig like the photo which consists of Raspberry Pi, DV3000, sound card, software, WiFi, battery and smartphone. You may use them as a friend of your daily exercise, walking!!I made hotspots and node adapters in total six to seven sets, but this is the very first ever set which is capable for accessing the networks supported by ircDDBgateway software. At this moment of time, only remaining issue is PTT as I prefer PTTing by using a speaker-mic rather than hitting a PTT button on a smartphone screen.I will be soon 70 years young! hi This requires skills for a soldering and programming but hope everybody could overcome difficulties you may be faced to. Thanks to a great product, DV3000 and people contributed for launching it.Very best 73s,  JA1SCW@ Olive Island in JapanThanks,  Satoru (Radio Name: Steve)

Update

GPIO PTT

Photo of Portable DummyRepeater w/PTT

Based on information from G8BPQ, Saturo was able to simplify the Portable DummyRepeater and remove the external USB hub which supported a serial connector to get PTT.  Now his PTT goes directly to Pin 3 on the Raspberry Pi.

DummyRepeaterDV3000-2

Block Diagram

 

DR-DV3000

Portable Dummy Repeater with DV3000

DV3000 Analog to D-STAR Bridge

VK5ZEA, Michael, of Port Lincoln, Australia treats us to another of his wonderful YouTube videos.

Using a Raspberry Pi, DMK URI, DummyRepeater and analog radio, Michael demonstrates bridging analog FM and D-STAR.

International Shipping

I did a quick check today on our International Shipments via the US Postal Service.  Here are the results:

DELIVERED:

  • Australia
  • Canada
  • France
  • Netherlands
  • Poland
  • Spain
  • Switzerland
  • United Kingdom

HELD FOR PAYMENT:

  • Germany

STILL IN PROCESS:

  • Belgium
  • Ireland
  • Italy
  • Japan
  • Norway
  • Russia
  • Ukraine

DV3000 Back in Stock

We have have received another batch of 100 and all back-orders have been filled leaving about 70 in stock.

We’re working on some app notes as well.

Well that was quick …

The first 100 DV3000s are sold at the intro sale price and have been shipped to 10 different countries. We have started a new build cycle and are accepting back-orders. We intend to maintain units in stock after that.

Thanks for getting this off to a great start!

Preparing the Raspberry Pi for DV3000 Applications

See the basic installation instructions for the DV3000 and the dv3000d daemon in the document DV3000 – AMBEServer

Note: All production DV3000 units are configured for 230400 bps and do not have jumpers. 115200 bps is insufficient, but the board can be easily modified to add jumpers to configure baud rate, see the schematic at in the datasheet.

The dv3000d is the basic building block for the first set of applications for the DV3000.  It is a server which receives PCM audio over a UDP socket and returns AMBE or receives AMBE and returns audio.

DummyRepeater from the Yahoo! pcrepeatercontroller forum can access the daemon either locally or over a UDP/IP link. DummyRepeater in conjunction with ircDDBGateway will allow you to link to reflectors and repeaters around the world.  See notes.

You will also find utilities to convert between ‘wav’ and ‘dvtool’ or ‘ambe’ files in the ircDDBGateway file AMBETools.

 

DV3000 AMBE Card Available Now

The UDR supports an optional AMBE Vocoder card for D-STAR Digital Voice or DV. During the last prototype layout of the UDR, it occurred to me that there are over 2 million Raspberry Pis, so if we used the same connector as the Pi, it would have the following advantages.

  • Pi users would have access to AMBE
  • Software development would be in parallel with UDR development
  • Other cards made for the Pi could potentially be used on the UDR

Jonathan Naylor, G4KLX, has adapted his Dummy Repeater to work with the DV3000 on the Pi. This let’s hams talk over the D-STAR network using their computer instead of a radio. He also built several wav / AMBE conversion utilities for testing and comparison of different vocoders. Jonathan joined us at Hamvention for the release of the DV3000, where we sold over 30 units.

The AMBE3000 Chip supports vocoding for:

  • D-STAR – Supported NOW by G4KLX
  • DMR and dPMR
  • Yaesu Fusion
  • P25 Phase 2

Check out the DV3000DS or go to the PRODUCTS page to buy online.

There is a Hamvention special for $89.00, which will be honored for 1 month or until the first run of 100 is gone.

Receiver Sensitivity

Just out of the RF Lab, the receive chain with 25kHz IF is fully functional and initial testing shows a MDS (Minimum Detectable Signal) of better than -130dBm (0.07 uV). That’s before any process gain in the modem section. We will release complete Eb/No curves for the receiver prior to shipment.

Here’s a sample of the receiver performance at 440MHz. Dennis hooked a key up to his Agilent Sig-Gen. Note if you were actually working CW you’d add in a SW narrowband audio filter after the 25KHz IF stage.

-100dBm -110dBm -120dBm -130dBm

 

This completes initial testing of the LNA thru the IQ XCVR and into the processor. The 100kHz IF stage needs some changes in the SAW filter circuit, so we can’t check that off just yet.

Onward!

UDRX is on the air

We have the Transmit side of the RF deck checked out and operational. This includes the 9600 FSK Modem and 25kHz IF stages.

Dennis is working on the 100kHz IF while I’m checking out the TX/RX switch.

Keep the faith,
Bryan K7UDR