Allstar Link Node Build - Part 1

The Digital Age and the Internet of Things

"Plus A Ham Radio Project for the Digital Age"

As I wrote this blog post near the end of 2020, I cannot help but marvel with admiration at the technological achievements that have been made since I ventured into the world of radio and electronics back in the 1970's.

 

I have witnessed the development and progression of electronic devices, such as transistors, integrated circuits and optical devices, such as LEDs and LCD displays.  These electronic wonders helped develop electronic and analogue equipment, such as photocopiers, printers, fax machines, modems, computers and mobile phones, all of which are now part of everyday life.

In the late 1980's I built my first personal computer using an Intel 80386 microprocessor, which contained 275,000 transistors, fast forward to today and my current computer is equipped with an AMD Ryzen 7 3800X microprocessor that contains 3,800 million transistors. This is a prime example of how modern electronics has evolved and shrunk into what is known as Nanotechnology.

Without the advancements in technology and miniaturization, we would not have the internet or mobile phones and, therefore instantaneous worldwide communications and connectivity.

 

In modern times can you imagine a world without the Internet, eBay, Netflix, Skype, Facebook or Twitter?

 

Welcome To the Fourth Industrial Revolution, The Digital Age!

 

 

I have always embraced new technology, whether it has been a means to improve the way I work or to further my technical knowledge and curious interests.

 

My interest in technology, computers, electronics and radio leads me nicely to document my first blog project, which brings together all of these things.

 

I am going to build an AllStar Link node, which is basically a hot spot connected to the internet that facilitates two-way communication using a voice over Internet Protocol.

 

The AllStar Link network runs on a platform called Asterisk,  a powerful open source PBX (Private Branch Exchange) that can connect many nodes together.

 

Nodes or hot spots are typically accessed using a radio transceiver and the technology provides the linking of these nodes and two way communications throughout the world.

 

Please note you need to be a licensed radio amateur to gain access and use AllStarLink.

Access to the AllStar Link network requires registration/sign up to the AllStar Link website and you can do this by clicking on the following link button:

 

Once you have completed the sign up on the AllstarLink web site, you should be able to login with your credentials. The website should now display an additional drop down menu titled "Portal" as illustrated below:

 

Follow the online process to request a node number. AllStar Link is run by volunteers so please be patient  while your request is processed, I got my node number within 24 hours but you should be mindful it may take longer!

I have outlined the basic requirements needed to join and gain access to the AllStar Link network. For further information, consider reading through the Allstar documentation, which is located on Wiki and can be viewed by clicking on the following link button:

 

 

If you have successfully registered with the AllStar Link network and obtained a node number, you are ready to access AllStar Link.

 

 

What follows next is the detailed documentation of my own "Hotspot Node" build that I use to access the AllStar Link network.

First is the list of parts & hardware I decided on for my node build. Your own ideas and preferences may be different to mine!

 

Parts Inventory For Building My Node Hot Spot

• Baofeng BF-888S 16 CH UHF 2 Way Radio - available for £10.00 or less from eBay

• CM108 USB Sound Card - available for £5.00 or less from eBay

• Raspberry PI 3 Model B Plus - available for £30.00 or less from eBay

• Raspberry PI 4 Genuine Power Supply - available for £11.00 or less from Amazon
  

• LM2596 DC-DC Buck Converter - available for £2.50 or less from eBay

• LM317 Variable, DC, Regulator Module - available for £2.95 or less from eBay

• Aluminium Enclosure Case 54x154x150mm - available for £14.00 or less from eBay
  

• Miniature SPST Toggle Switch - available for £1.49 or less from eBay

• Miniature Momentary Push to Make Switch - available for £1.49 or less from eBay

• DC Chassis Power Socket 2.1mm - available for £1.00 or less from eBay

• DC Power Plug 2.1mm - available for £1.00 or less from eBay

• 1 of 5mm Standard Diffused RED LED - available for £0.99 or less from eBay

• 1 of 5mm RGB Diffused Common Cathode LED - available for £0.99 or less from eBay

• RJ45 Panel Mount Socket With short Cable/Plug - available for £6.99 or less from Amazon

• 8 of M3 & M2.5 PCB Standoff Spacers - available from eBay or Amazon in kits

• M3 & M2.5 Screws - available from eBay or Amazon in kits

• Various Cable Connectors - Molex etc

• 2.4mm Heat Shrink Sleeve - available in 1 Meter lengths for £0.99 or less from eBay

• 3M Stick on Rubber Feet 20mm by 20mm - available for £1.75 or less from eBay
  

• Front Panel Label - produced in Corel Draw on personal computer
  

• A Few resistors & capacitors - from any electronics part supplier or eBay
  

An affordable transceiver

My AllStar Link node is built around a cheap Baofeng BF-888S UHF hand-held transceiver commonly available from eBay & Amazon. The transceivers have 16 channels that are programmable via an optional USB cable. The BF-888S has gone through several revisions, mainly with changes to the PCB. The version that I have is the latest revision with a short PCB and a USB battery charger. Previous revisions contained a longer PCB and a plug-in mains power supply for charging the battery.

The radios are factory programmed at various frequencies around 462 MHz; this is outside the UHF amateur radio spectrum so the radio's are not usable for ham use straight out of the box.

In preparation for building an Allstar link node, the radio needs programming to a suitable node frequency.  I used the free Chirp software to program my radio using a  USB cable purchased from eBay. 

It should be noted that the radio can still be programmed or reprogrammed once it has been built into a node enclosure but it is easier to do it beforehand!

 

 

 Baofeng BF-888s Prior To Being Stripped Down

Dismantling the transceiver

First remove the battery if it is attached, pull off the volume and channel change knobs and remove the four screws, as shown below, note the bottom screws have a torx style screw head so you will need a torx T9 screwdriver for these.

 

Remove the small black plastic top back cover plate.

Remove the three brass nuts that secure the antenna socket, volume control and channel change switch. All of the nuts have slots cut into them and I found that a pair of tweezers fitted nicely into the slots, making their removal easy.

Separate the alloy chassis from the front plastic shell by lifting the bottom of the chassis up and sliding it back, as illustrated below.

De-solder the two speaker wires from the main PCB and discard the front plastic shell and speaker, as these will no longer be needed.

 

 

Remove the 4 small screws that secure the PCB to the alloy chassis, the plastic bush from the antenna socket and the rubber gasket from the jack sockets. Note at this stage the PCB will not separate from the chassis!

The final step of removing the PCB from the alloy chassis requires de-soldering a lug that connects the PCB to the positive battery terminal.

 

 

With the PCB now free of the chassis, de-solder and remove the antenna socket, which will be reused and mounted on the aluminium project case later. Also de-solder and remove the LED and Electret Condenser Microphone. The PCB holes are through hole plated so care should be taken not to damage these while removing components.

  

The Baofeng radio transceiver is now stripped and ready for the next stage, where I will add all the necessary wiring for connecting to the CM108 USB sound card and power supply.

Until next time... 

 

 

73's From Andy G6LBQ

Its all about the Radio Ga Ga...