BRIAN (SM)

Overview


BRIAN (SM) (Baofeng BF-888S Radio Interfaceto the Allstar Network) is a kit construction project designed by N8AR that implements a Raspberry Pi hosted Allstar node using the circuit board and other parts from a Baofeng BF-888S as the node radio operating in the amateur UHF (70 cm) band.  An Allstar node can be implemented using BRIAN (SM) and a Raspberry Pi. BRIAN (SM) contains it’s own USB audio interface realized using surface mount parts rather than using a modified USB sound FOB as done in the original BRIAN .

BRIAN (SM) Front View
BRIAN (SM) Rear View

The BRIAN (SM) electronics is housed in an extruded aluminum enclosure measuring 3.94L x 2.98W x 1.42H inches.  A “rubber ducky” antenna is mounted to an SMA connector on the rear of the enclosure.  Internally, the Baofeng circuit board (modified by the builder) is mounted to a motherboard which contains the radio interface circuitry and jumper wire connection points to simplify wiring to the Baofeng board.  The motherboard uses a combination of surface and through-hole parts.  In the BRIAN (SM) kit, the motherboard is supplied with all the surface mount parts installed.  The kit builder installs seven through-hole parts, modifies and installs the Baofeng board and completes final assembly.

BRIAN is connected to a Raspberry Pi using a USB A male to USB B male cable.   This cable also supplies 5 VDC power to BRIAN (SM).  Front panel LEDs on BRIAN (SM) indicate the status of the unit – BRIAN POWER (green), RADIO POWER (green), COMM STATUS (blinking green), COS (yellow) and PTT (red).   The BF888S nominally supplies 1 watt of RF power.   Optionally, the construction manual contains information on a method to modify the Baofeng BF888S board to reduce the output power to 20 – 50 milliwatts…. perfect for a local Allstar node! This modification also reduces the BRIAN (SM)current requirements to less than 300 mA.

Baofeng BF888S Circuit Board Installed on a BRIAN (SM) Motherboard

Features

  • Uses low cost, proven CM119B USB Audio IC
  • Uses the circuit board from a Baofeng BF-888S UHF HT
  • Standard SMA female connector and antenna
  • Powered by Raspberry Pi (3/4) via USB cable (A male to B male)
  • Nominal 1 watt RF power
  • Low power modification (20 to 40 mW) if desired
  • Motherboard, daughter board design simplifies wiring
  • Rugged RFI-resistant metal enclosure
  • Blank metal end caps with modification drawings

Schematic

BRIAN (SM) Schematic

Parts List

BRIAN (SM) Kit (BF888S Radio and USB Cable Not Shown)

Kit Construction

Construction Summary

The BRIAN (SM) kit contains all of the parts required to build the device except the Baofeng BF888S circuit board and the USB Type A to Type B M/M cable. The motherboard in the BRIAN (SM) kit is provided with all of the surface mount parts installed. The kit builder installs 5 LEDs, the USB Type B connector and the SMA RF connector. Also, blank painted end caps for the case must be modified by the kit builder.

BRIAN (SM) Motherboard with all Surface Mount Parts Installed

Construction of the BRIAN (SM) kit consists of the following steps:

  • Install 7 through-hole parts on the motherboard.
  • Disassemble the Baofeng BF888S HT. Remove and modify the circuit board.
  • Mount/wire the BF888S to the BRIAN (SM) motherboard.
  • Drill/file the required holes in the two case end caps per supplied drawings.
  • Final Assembly

Construction Manual

The construction manual for BRIAN (SM) may be downloaded by clicking below:

Ordering Information

BRIAN is available as a simple parts kit (less the Baofeng BF888S circuit board) for $40 plus shipping. Send an email to kitsforhams@gmail.com for ordering and delivery information.

Support

Support of BRIAN (SM) is provided via the BRIAN group at  www.groups.io

The purpose of the BRIAN group is to serve as the main hardware support source and discussion group for hams building and using the BRIAN or BRIAN (SM) Allstar Node. Support of the Allstar distribution you install in your Raspberry Pi and use in conjunction with BRIAN is best obtained from the source of the Allstar distribution (i.e. allstarlink.org or hamvoip.org).

Please join the BRIAN group for the latest information on BRIAN.

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