SDR Cube Transceiver

Online Assembly Guide

Detailed construction notes for building and testing each of the SDR Cube kit modules

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Start Here for Quick Kits ==>    Main Enclosure    Digital Subassembly Test    Final Assembly    RF Functional Test   


Digital Sub-assembly Test                             ... (Section version 1.0b)


By now you should have the DSP, Controls and I/O boards complete.  Also, you need to at least have Cable #1 made from the Internal Cable Kit.  (Cable 1 enables you to connect the DSP and I/O boards.)


Connect the boards as shown in the photos below, and attach a 12V power source - ideally a battery as shown, or a current limited at 200 ma.


Apply power and turn on the power switch on the I/O board (flip it "down" toward the I/O pc board).  NOTE:  Be careful that the mounting tabs of the voltage regulator hanging off the I/O board don't touch the bottom of the DSP board!


You should now see the LCD illuminated with a blue light.  Using a pointed object such as the end of an Exacto blade, carefully move the R71 "Contrast" trimmer pot (located on the Controls board just below the LCD) until you see the characters and graphics appear in a bright, clear manner.


If you have a way of measuring the power supply current being supplied to the SDR Cube board set, it should be about 130 ma.  Anything significantly more or less than this indicates problems and you should go down to the Troubleshooting section of this page.


Rudimentary tests ... You should be able to ...

      [More ...]


LED power-on sequencing definition ... When you power-up the Cube, the red and green LEDs on the DSP will illuminate in a way that provides useful diagnostic information about the health of your Cube boards ...


Extended Tests using the Aux serial port the Terminal Menu...

Construct the Aux Cable serial port adapter, as shown in the diagram, and connect the Cube to a  PC running a terminal program (TeraTerm, HyperTerm, ProComm, et al. 

When you power up the Cube, you will see the Terminal Menu displayed on the PC screen, offering a number of useful command for testing and exercise of the Cube.

SDR Cube SW started

George Heron N2APB / Juha Niinikoski OH2NLT

Version: v1.00

Date: 07.11.2010


CPU speed, FCY = 38707200 Hz

24LC256 EEPROM I/O init

User data restored succesfully

Timer system started

ADC system started

Battery voltage = 11.6V

DSP filters initialized

Codec started

Si570 I2C init

DDS started

Si570 LO selected

Change Terminal UART to user baud rate 9600

Change PSK Modem UART to user baud rate 9600


SDR Cube UART user baud rate = 9600

Starting Main


----  SDR Cube Test Commands,Ttstamp = 8(s)  ----

Battery voltage = 11.6V


i print system info

a print ADC data

p print I/O port data

e read Encoder & switch

t test tones

d test PWM DACs

o test RF attenuator relay outputs

x print Si570 factory XTAL freq

l test LCD



---- SDR Cube Debug Commands, see source code for details ----


q op mode flags

s print Si570 registers

c set Codec DCI mode

v Codec volume controls

m Mic On / Off switch

1 Show LCD characters (chgen test)

2 Write LCD

3 Write Large LCD

w Write EEPROM, Caution cauce factory default reset at next start


[More ...]


That's it for now ... you have a minimally operational SDR Cube!  In the next installment of this Assembly Guide, we'll go through a more deliberate and exacting set of operational checks, including audio, paddle input, Morse output, etc.  Also a detailed Troubleshooting section to assist in finding/correcting problems.


Click on any of the photos below to see a larger view ...







The Cube board set is complete and (hopefully) operational now!  Set it aside and next move on to building the SR-base.



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Page last updated:  Dec 28, 2010