Overview
The SHARI (SA818 Ham Allstar Radio Interface) PiZero Allstar Node is a kit construction project that implements a Raspberry PiZero 2W (must be the 2W with no installed pin headers) hosted Allstar node using a NiceRF SA818A embedded UHF (420 – 450 MHz) or a VHF (144-148 MHz) radio module. Three USB ports with microB connectors are provided by a USB hub on the PiZero PC board. This permits the node owner to utilize wired ethernet connection to the node using a microB USB to ethernet dongle cable. Power is provided to the node using a suitable Raspberry PiZero power supply (microB connector)
The VHF or UHF radio module, interface circuits and the USB hub for the PiZero are located on a custom printed circuit board using surface mount components. The Raspberry PiZero 2W plugs into the PC board via its 40 pin GPIO connector and a custom USB adapter cable.
Features
- Uses a CMedia CM108B USB Audio IC.
- Uses a NiceRF SA818S UHF (420-450 MHZ) or VHF (144-148MHz) embedded radio module
- LTCC lowpass output filter ensures compliance with FCC Part 97 spurious requirements
- 250 to 500 milliwatts RF output power.
- Three microB USB ports to plug in USB devices such as an external microUSb to ethernet cable adapter for a wired ethernet connection or an external keyboard.
- Hammond extruded aluminum metal enclosure (approximately 3.25 x 2.25 x 1 inch).
- RX/TX serial connection from the PiZero GPIO to the SA-818 radio module to program RF module parameters including RF frequency and CTCSS/CDCSS codes.
- Clamp-on ferrite provided to mitigate buzz interference from high RF fields near the Pi power supply.
- Raspberry PiZero 2W, power supply and microSD card provided by kit builder.
Construction and Setup
The SHARI PiZero kit parts are shown in the next photo. The kit builder supplies the PiZero 2W (must be a 2W with no installed pin header) and a PiZero power supply.
The SHARI PiZero PC board is supplied with all the small surface mount parts installed. The kit builder installs two through-hole connectors, an SMA RF connector and the SA818 radio module. The builder also installs two pin header connectors in the PiZero. A pre-built cable is supplied to connect the PiZero to the SHARI PiZero motherboard. 3D printed end caps are provided as well as blank end plates that the builder can modify with the required holes (if desired).
Detailed construction and setup documents are provided with the kit. (Please request them by sending an email to kits4hams@gmail.com). Note that the Paspberry PiZero board does not have an ethernet jack. Since a wired ethernet connection is the preferred way to set up the HamVOIP image, SHARI PiZero contains an ethernet hub with 3 microUSB jacks so that a builder supplied microB USB to Ethernet adapter cable can be used for setup.
Ordering Information
SHARI PiZero is designed as a kit for construction and use in the amateur radio service by licensed amateur radio operators who can assure that the SHARI PiHat kit they are using meets required operating requirements including frequency, bandwidth and required power levels at the fundamental and harmonic frequencies. There are two SHARI PiZero kits:
SHARI PiZeroU (UHF-70cm, 420-450 MHz)
SHARI PiZeroV (VHF-2 meters, 144-148 MHz)
SHARI PiZero kit – SHARI PiZero is available as a parts kit for, $100 (UHF and VHF). You supply the Raspberry PiZero 2W, PiZero power supply and microSD card . Please be sure to request and study the SHARI PiZero construction manual to be sure you own the required tools and possess the required mechanical and soldering skills to build the kit. We will solder the SA818 radio module onto the PCB for an additional $5.
Fully Assembled and Tested SHARI PiZero – We can also build and test the kit for you. For this option, we supply the PiZero 2W and power supply also. An assembled SHARI PiZeroU or PiZeroV is $205.
Optional microUSB to Ethernet Cable Adapter – We can include an optional microUSB to Ethernet Cable Adapter with your order for $10. It has been tested to work with the HamVOIP Allstar image.
Shipping – Shipping to US destinations is $9 via USPS Mail provided your order fits in our standard shipping box. Payment via Paypal is preferred.
Complete the order form and email it as an attachment to kits4hams@gmail.com. We will check your order, add it to our waitlist and notify you with an approximate waiting time, and then send you a invoice when it is ready to ship.
Support
Support of SHARI is provided via the SHARI group at http://www.groups.io/g/shari
The purpose of the SHARI group is to serve as the main hardware support source and discussion group for hams building and using the SHARI Allstar Node. Support of the Allstar distribution you install in your Raspberry Pi and use in conjunction with SHARI is best obtained from the source of the Allstar distribution (i.e. allstarlink.org or hamvoip.org).