The HotSpot Adapter (HSA)


P  R  E  L  I  M  I  N  A  R  Y


As the name would suggest, the HSA indeed is a combination of the products so far. The best features from the famous Mini-HotSpot (MHS) revision B were combined with some of the features of the also-famous Node Adapter to create a new board with all the features combined.

Designed to fit in a nice, small enclosure (which is included in the kit) the new board tries to pack as much functionality as possible in the little package.

Although the enclosure is shown as a regular square type, it is also available in a somewhat more oval-styled version for those who prefer that.

For communications, connectors are provided for the D-SUB9 radio port, a 2.5mm "stereo jack" for the serial port (many GPS and USB/serial cables use this pinout) and a Mini-B style connector for USB.

A pre-made Radio Cable is also available, this cable will connect the board to most modern transceivers that feature a PS/2-style ("MiniDIN-6") port labelled "data", "packet" or "tnc".

For status, the board comes with the (OK, agreed, maybe a little TOO bright at times) blue power LED, a green COS/RX LED, a red TX/ERROR LED, and three yellow LEDs to indicate relative signal quality of the signal being received by the radio. In addition to these, two LEDs are provided for user status (see below.)

To allow for several interesting extras (see below), we did change the microprocessor to its larger brother, the PIC8F4550 from Microchip. Although almost the same as its little brother used so far, this one features many more programmable I/O pins, which can be used by the various option modules that can be used with the board.

Option modules?

Yes!  Rather than fixing everything on a single PCB, we decided that many amateurs would enjoy being able to play with it. As such, the HSA can be considered a "main board" with all the basic hardware, and in that state, it will act like a normal Mini-Hotspot / Node Adapter system as you'd expect it to. This basic board will work with DVAR Hotspot, OpenG2, NI-STAR, and so on without changes to the software.

All the extra features can be implemented on two "series" of option modules which can be plugged in to one or more of the five (!) expansion connectors.  Two sets of mounting holes are provided for extra support of these modules, as well.

At this time, the following modules have been taken into consideration:

DV Adapter (DVA)    

The first module that was considered, and which was the reason why this project came along. This module adds analog audio capabilities to your system, and, as such, it can be used as a standalone DV Adapter (plug in a speaker, a microphone, and you're on the air !) or it can be used as an analog/digital gateway system, or as a source for a web stream, or...  think about it!

User Option Board (OPTION)    

Although first designed as "just" an LCD add-on board, it was decided that users would have a lot more fun with a general "breakout" type of board that could be used to hook up home-brew extensions to the system.

So, this board features two I/O connectors that can be used to connect it to a breadboard, your own PCB, and so on.  Function names are printed next to the pins for easy (and safe) testing.

The board also features an HD44780-compatible LCD connector, an I2C real-time clock (backup battery is mounted on the bottom side), an I2C local/remote temperature sensor/thermostat, as well as an I2C-based GPIO/LED extender, which LEDs and I/O pins.

Integrated Analog Repeater (RPTR)    

[picture not available yet]


This little board adds the circuitry to implement a 'regular' analog repeater function to the system. It includes the audio amplifiers/limiters, the audio switch, a CTCSS/SELCALL/DCS tone code processor, and so on.  Combined with the SoftCOS feature in our firmware, it creates a very small, dual-mode repeater system!

It also features the LCD and RTC circuitry found on the Option Board module, so you can monitor the system at a glance.

This board can co-exist with the DVA module, allowing for  an analog signal monitor as well!

RF Access Point (TRX)    

[picture not available yet]


Requested by many, this board implements a miniature RF transceiver using the SA58646 chip from NXP.

As this board can co-exist with the DVA board, we might be able to implement some very interesting features in the firmware!


Since the design implements a full SPI bus as well as an I2C bus, the possibilities for adding your own extensions are almost endless.  One of our beta testers is already having fun with designing his environment status/control system, including sensors for temperature, humidity, system voltages, and so on, and the option to send an SMS Alert to a mobile phone if something does't look right!


Right now, the first batch of test boards has been received and forwarded to the test users, who so far are having fun with them. The boards work as expected, and only minor changes have been done, mostly cosmetic ones.

The firmware so far has proven to be as rock-solid as its "NODE" platform counterpart (which is the same source code, just compiled for a different platform) and we expect to be able to order the first production run sometime in late October.

UPDATE: testing for the HSA itself and the Option Board have been completed; the final design for these boards will be sent off for production during the second week of November !

If you feel like this is for you, contact us for more information!


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