WJ8888/B2 25kHz Synchronous Optocoupler Remote Control Interface This site is not affiliated in any way with the Watkins Johnson company or DRS Technologies, the present owners of WJ
Gaithersburg, this is just a Hobby site!
14-09-2006
Welcome
Welcome to our site about the Watkins Johnson WJ8888/B2
This site is dedicated to our optocoupler interface which controls the WJ8888 by remote with Windows XP.
All electronics, designs, layouts, schematics and software source codes remains property of Peter De Coninck & Geert De Coninck
the interface adds some new features to the radio receiver such as: additional tuning with 100kHz, 1Mhz, 10MHz resolution direct tuning with keypad presets of frequencies automatic up and downtuning of frequency with time interval gain mode, if bw and detection mode fully controlable extended memory to save radio settings operating with RS232 or USB - RS232 converter
WJ8888 now also running with Windows Vista
13-09-2006
About us
Electronics and design: Peter De Coninck ONL4234
Living in Flanders, in the city of Antwerp, the Belgian major world port. Born in 1955, I got the radio bug as a kid from my granddad Jan De Coninck, who sailed in the 1930ies with the Belgian training tallship ‘ MERCATOR’ on a scientific expedition around the world, as a wireless operator.
Born in 1973 and living in Mortsel, Antwerp. After more then 10 years of graduation at VTIB Borgerhout (Karel de Grote Hogeschool) and still interested in technology and software, I started with my brother this adventure of designing the interface.
Special thanks and credits:
Byron Whartnaby (K3OY) - Escondido - California - USA Check out our new website at www.kmans.net Mark Alberts - Almere Port - The Netherlands www.mcselec.com Erik Salaj - Kosice - Slovac Republic Dieter Suckale - Bad Vilbel - Germany Alain Smolders - University of Antwerp - Belgium Jan Hynneke - Demotech - Denmark Our dad, for his unrelenting belief in the success of this project... Peter's XYL, Yolande, for enduring our endeavours with PCB etching in her kitchen...
12-09-2006
Software
PC:
The entire Windows XP program is written in Borland C++ Enterprise 6.0.
Microcontroller:
The microcontroller firmware was written in BASCOM which is a Basic language based compiler for the Atmel microcontroller family. The machine code is programmed into the processor using the ABCEDIT software package.
The system consists of a synchronous communication board installed in the WJ8888/B2 receiver. This board is then connected by a special MIL connector to our optocoupler interface. Then it is connected by RS232 to the PC.
The hart of the interface is the ABC mini board with an Atmel AT90S8535 microcontroller mounted. The firmware in the microcontroller receives RS232 datapackages from PC and convert it to the 25kHz synchronous protocol used by the receiver. On command of the receiver the interface starts sending the datapackage.
Additional information about the Atmel family you can find here http://www.atmel.com/
The radio receiver is normally equiped with a 25kHz synchronous communication board.You can see a photograph of it right here. The manufacturers part number of this board is 791200-1.
The synchronous communication is done by DS8820A and DS8830 IC's.
The DS7830 is a dual differential line driver that also performs the dual four-input NAND or dual four-input AND function. TTL (Transistor-Transistor-Logic) multiple emitter inputs allow this line driver to interface with standard TTL systems. The differential outputs are balanced and are designed to drive long lengths of coaxial cable, strip line, or twisted pair transmission lines with characteristic impedances of 50Ohm to 500Ohm. The differential feature of the output eliminates troublesome ground-loop errors normally associated with single-wire transmissions.
The DS8820A is a digital line receiver with two completely independent units fabricated on a single silicon chip. Intended for use with digital systems connected by twisted pair lines, they have a differential input designed to reject large common mode signals while responding to small differential signals. The output is directly compatible with TTL or LS integrated circuits.
Making of : preparing the 40 DIL on the ABC miniboard
Here we are preparing the ABC mini board on a 40 DIL socket.
07-09-2006
Making of 2 : preparing the photo-sensitive epoxy PCB
Ready for take off. Here we are ready to fire some 300W UV ray's onto a photo-sensitive epoxy PCB.
06-09-2006
Making of 3 : Peter etching the PCB
Just counting the minutes for etching the PCB, in the kitchen.... Wife standing by in background, wondering whether husband is beyond salvation ...
05-09-2006
Making of 4 : placing the components
Finally starting the real work.
04-09-2006
Making of 5 : finally done
The complete PCB. Only find that last component.
03-09-2006
You Tube 1 : 25kHz signals
Here you can find some animation of the protocol signals of the WJ8888 radio receiver. The signals from the receiver are displayed on a Dynatec Oscilloscope 8120 (2x20MHz). The first channel is the 25kHz clock signal received from the WJ8888 and the second channel is the 64 bit wide dataword send from the WJ8888. Triggering was done on the first channel. http://nl.youtube.com/watch?v=oyzgFfv6JnQ
Hopefull we get some more animations online soon.
05-08-2006
Screenshot 1 : PC software interface
Here you can see a screenshot of the PC software interface running under Windows XP. All important buttons and indications are grouped in one screen. Down at the screen you can find a LCD which displays all radio receiver settings in text format. Above the LCD you have the tuning resolution group. Please notice the additional resolutions 100kHz, 1MHz and 10MHz. At the right of the resolution group you find the selectors for IF bandwidth, gain mode and detection mode. There is also a keypad tuning feature for direct tuning. Settings for the RS232 protocol is also integrated into the main screen. At last there is a bit display which indicates binary patterns of the protocol data send to the receiver.
04-08-2006
Screenshot 2 : Start up screen
Start up screen
03-08-2006
Screenshot 3 : LCD Mini Monitor Mode
LCD Mini Monitor Mode pop up screen
02-08-2006
Screenshot 4 : Maxi Monitor Mode
Maxi Monitor Mode
01-08-2006
Screenshot 5 : TTL square wave analyzer
Here you can see a TTL square wave analyzer. This analyzer gives in realtime the status of the databits send to the receiver. The analyzer is included as a popup so you can call it as an overlay. Each databit in the protocol is graphical shown with low and high signals giving a 64 bit wide wave.
31-07-2006
System overview
This schematic gives an overview how the system works:
30-07-2006
Optocoupler interface
The interface is designed with optocouplers for optimal electrical insulation between receiver and PC.
29-07-2006
Microcontroller
We used an ABC mini board with 40 DIL package. The heart of this circuit is an Atmel AT90S8535. There are 32 user configurable I/O available giving us plenty of IO to do the job. Each I/O pin is software definable as input or output. On the board there is also a MAX232 IC mounted so we can communicate with RS232 protocol. On the ABC mini board there is also an in circuit programming connector so we can program the microprocessor without disconnecting the board out of the circuit giving us more flexibility during debugging and maintenance.
28-07-2006
LCD
A 16x2 LCD screen is used for information about the internal signals of the microprocessor. You can follow in real time the information on the LCD. Also the LCD can dump additional information such as: radio settings, binary patterns, CRC checks, etc. In combination with the software TTL square wave analyzer this gives a lot of information about the actual status of the protocol. A special data led output is also available which gives the status of the databits send to the receiver.
27-07-2006
MIL Connector
The project was put down for a while because we searched hard to find the correct MIL connector. The part number of the MIL connector is JTG06RE12-22P(SR). Please notice that the photograph does not represent the correct connector, although it is used to give an idea of a MIL connector. The Amphenol company is one of the largest manufacturer of military connectors. A large amount of documentation you can find on the website http://www.peigenesis.com/amphenol_pdfLibrary.html. You can find also information at http://www.amphenol.co.uk/. A handy reference document is available at : http://www.amphenol1.com/KnowConnectors.pdf
25-07-2006
Testing
Debugging and testing the software was done using a STK500 development board. For testing purpose we did use Atmega8535 and Atmega16 microprocessors running at 8Mhz. This means that the microprocessor executes 8.000.000 instructions per second. Prior of debugging the software was simulated using the BASCOM internal simulator.
The WJ8888 can be equipped with two different communication boards. One type is the asynchronous, while the other type is the synchronous board. Please notice that these boards were optionally installed, so it is not sure you have a board installed at all. The only way to know for sure is to open the WJ8888 and have a look at the internal slots. The manufacturers part number is 791200-1 for synchronous IO, and 791201 for asynchronous IO.
Our software is designed for two platforms, so both asynchronously and synchronously protocols. Due to lack of an asynchronous board we could not test the asynchronously version fully, although we have tested it on two computers, one simulating being the WJ8888.
If you have installed an asynchronous board, you don't need the special interface and you can run directly the WJ8888 by RS232 protocol.
On the other hand, when installed a synchronous board, the interface is needed to have the system working. The PC software always converts the setting on the screen into a asynchronous datatable. Only when the synchronously mode is selected the software calls a special mathematical function to convert the asynchronous table into a synchronous table. This is done because place and amount of bits are different in both modes. Once the synchronous table is converted, additional header, command and CRC checksum characters are added. This table is then send asynchronously, still including start, stop and parity bits, to the internal UART buffer of the microprocessor. The microprocessor scans on unique header characters in the datastream, and once found them, the microprocessor accepts the datapackage as being valid data. When data is validated, the microprocessor starts stripping start, stop and parity bits from the received table. After stripping, the databits are stored into an array which can be addressed by x, y parameters, where x is a byte counter and y a bit counter. After filling the array, the microprocessor start a command call to the radio receiver. Once the receiver have received this command call, it switches into remote mode and starts giving back clock pulses to the microprocessor clock input. The microprocessor read this clock pin and once received a clock signal it sends out a databit selected from the array. After the databit is send on the dataline, the internal x and y counters are incremented and the microprocessor waits for the next clock pulse from the WJ8888. This is done for a total of 64 clock cycles for a full command call. After 64 clock cycles the microprocessor resets the command call giving the WJ8888 the command to shift the received data into the internal memory register, thus updating the segment display and the lamp indicators on the buttons. After one command call the receiver settings are the same to the settings of the PC. Each command call longs for about 2.56 milliseconds. After this the PC and receiver can handle a new command. A new command call is triggered by two different ways. One way is done using a keeping alive signal which triggers every 1350 milliseconds. Another way is to check the actual data settings with the data of the prior command cycle. If both datatables difference, a new command call is triggered. Combination of both trigger signals giving us a stable and fast refresh rate of the WJ8888.
Examples where synchronous datacommunication is used, includes keyboards, aviation black boxes, etc...
23-07-2006
Watkins Johnson History
This site is not affiliated in any way with the Watkins Johnson company or DRS Technologies, the present owners of WJ Gaithersburg, this is just a hobby site!
Watkins-Johnson Company, founded in 1957, was a manufacturer of quality microwave components, subsystems, and systems for the defense marketplace. Then in the late 1960s Watkins Johnson (WJ) purchased Communications Electronics Inc. (CEI) of Gaithersburg, Maryland. This became then the Communication Electronics division. Before this purchase WJ did not manufacture radios for surveillance use.
The old Watkins Johnson Telecommunications Group is at present day owned by "DRS Technologies". The official company name of this division is "DRS Signal Solutions, Inc".
Different owners, since 1999, including Watkins Johnson, Marconi, BAE Systems and Signia - IDT.
The following hardware, software & books were used during the project:
Hardware: Dynatec Oscilloscope 8120 2x20Mhz Oscilloscope APS230 2x30Mhz Function Generator 1x2Mhz Philips PM5132 Function Generator 0,1Hz-2MHz Power supply 0-30V/3A-12V/1A-5V/1A Logicport 34 channels 500MHz analyzer Atmel STK500 development board Laptop Promedion Intel(R) Pentium(R) 1.80GHz Laptop Compaq Armada Software: Bascom AVR 1.11.7.7 Avr Studio 4.12 ABC Edit 1997-2000 Borland C++ Enterprise 6.0 Books: AVR Microcontroller - Safinaz Volpe & Francesco P. Volpe / ISBN 90.5381.091.9 Elektuur Magazine June 2005 / NR° 500 USB Complete Second Edition - Jan Axelson / ISBN 096508195.8 Datacommunication - J. Clayes / ISBN 90.6200.180.7 Digital Techniques 1A - Cuppens J. Sayes H. Vandenheede H. / ISBN 90.6200.070.3 Microprocessor Techniques and Interfacing - Beuckelaers A. Van den Wijngaert W. / ISBN 90.6200.438.5
All used software is licensed.
21-07-2006
Links
Here you can find some of the websites where a link is active:
Demotech electronics was founded in 1995 by Jan Hynneke. At that time they developed and manufactured microcontroller systems and Highend Audio amplifiers for international companies like JBL, DynAudio and Arcitec Acustic. Please look at this awesome site with cool stuff : http://www.demotech.dk/. Thanks to Jan Hynneke for his "boosting" help and efforts.
Another intresting site where you can find a link to our project is the website of Charlos Potma which is setup for HAM related projects. You find lots of information on how getting started writing your own applications for the AVR microcontroller series of Atmel. All the described applications are written in Bascom, the Basic editor, where WJ8888 was also developed with. You can find the home page of Charlos at http://www.qsl.net/pa3ckr/ while the active link is located at http://www.qsl.net/pa3ckr/bascom%20and%20avr/teletroncontrol/index.html at the bottom of the page. Thanks Charlos!
Do you also have a HAM related website, or if you are a Bascom or AVR microcontroller guru, or just have a tiny free spot at your website and you like to include our project, we would appreciate it very much and include your site also on the WJ8888 project site. So please let us know!
24-05-2006
Components
Most important components:
7 Optocouplers 4N35, one for each data communication line between PC and receiver 1 Darlington Transistor Array ULN2803A, drives the communication leds and protect the microprocessor output ports 1 Hex Non Inverting Buffer Driver, CD4050, rectifies the communication signals after the optocouplers 7 NPN BC547 Transistors, drives the infrared leds of each optocoupler and protect the microprocessor and receiver current withdraw 1 Atmel AT90S8535 microprocessor, mounted on an ABC mini board, including a MAX232 driver 1 Hitachi HD4470 compatible 16x2 LCD
23-05-2006
Open source
Hereby we give the source codes of the project as open source.
The microcontroller source code you can find here http://www.uploadarchief.net/files/download/quad.bas while the C++ main program is here http://www.uploadarchief.net/files/download/unit2.txt. When you feel the need you can search to some mathematical formulas in the C++ source which were extracted from the WJ8888 manual and descriptions. If you look at the formulas you get some idea of the awesome magical design using only plain TTL logic without any microcontroller aboard! Great job WJ.
Because of the complexity to compile and build the project we can only provide the executable alpha version to have a look. Microcontroller source is available in both bas (Bascom) and hex (Machinecode) format.
Please notice that ALL source codes remain property of Peter De Coninck and Geert De Coninck. Because the source codes are presented as open source you may use excerpts in your own projects. When distributing, using, and presenting this source codes, by any type of media, please keep the information disclaimer intact.
In no event shall we accept liability in any way when using this software. Please notice that this software is just a part of the project and that a high skill in electronics and software is needed to make the project succesfull.
Please notice that ALL schematics remain property of Peter De Coninck and Geert De Coninck. Because the schematics are presented as open source you may use excerpts in your own projects. When distributing, using, and presenting this schematics, by any type of media, please keep the information disclaimer intact.
In no event shall we accept liability in any way when using this schematics. Please notice that this schematic is just a part of the project and that a high skill in electronics and software is needed to make the project succesfull.
WJ8888 now also running with Windows Vista
Debugging and testing the software was done using a STK500 development board. For testing purpose we did use Atmega8535 and Atmega16 microprocessors running at 8Mhz. This means that the microprocessor executes 8.000.000 instructions per second. Prior of debugging the software was simulated using the BASCOM internal simulator.
