Matey Modem - Prototype Page

This page will report the progress of the Matey Modem prototype page. Updated each week.

Updated March 2005 with some colour pics - showing their transmission times.

Some Initial Tests of Colour Capture

Compression for colour images is now working. These large, bitmap images were captured by the Matey prototype and transmitted with three levels of compression.

The horizontal colour tear lines are the synch separator not set up correctly. Also, the jaggedy verticals are also due to this. Needs a minor fix. The colour strips down the edges are dedbugging info, to be deleted once I have the final colour balance working.

Hot Issues Under Development

  • The announced message is being implemented. DOWNLOAD AUDIO SAMPLE.

  • The tone detector for sequencing transmissions has not been started. Not hard.

  • The remote dial in is being researched.

  • Somebody needs to check availability of FPGA XC4005-PQ100 since this is planned for the initial small run.

  • The motion detection software needs to be written.

  • The schematics have been sent out to David B to begin CAD entry. Complete except for questions on FPGA availability.


    The schematics are in this file PDF. Note that the varactor diodes around the video capture crystal are no longer needed.

    The OLD scans of the schematics are in this directory. They are for the monochrome version.

    A third relay has been added in case there should be any break-before-make problem with the exchange. Also, a pair of links are added to solve the same problem on the instrument side, but note that this will cause temporary direct connection of the local PSU to the line. This is ok if the local supply is floating, as in normal operation, but can be a consideration when scopes or laptops are connected to the unit, since these can upset grounding.


    Trials over a number of different phonelines are envisaged for the next few weeks.

    Sub-Assembley Status - Components Requiring Work Listed Only

    Announce Message

    The announced message is being implemented. DOWNLOAD AUDIO SAMPLE.

    I have written a program to take a wav track, downsample and compress it and download it to the flash.

    Motion Detection

    This is software yet to be written.

    Video Capture

    The PAL Colour capture is being prototyped at the moment. For economy the horizontal dot clock will be 4.33 Msps so the max horiz resolution will be 216 pixels.

    Remote Dial in Modem Code

    This has been planned. It will be V.22 1200 baud to start with. A standard V.8 connect sequence will be used so that a standard modem can be used to dial up the remote mateys.

    Receive Modem / Laptop Environment

    Some basic receive code has been written but a lot more work is needed. The laptop sound card has not yet been physically connected to the phone network.

    It is intended to use a stero capture card on the laptop (they are all stereo) and use one channel for the local signal and the other for the line signal. This enables the CO hybrid to be implemented in software on the linux as an offline processing stage. The canned message can also be played out of the laptop from a wav file if desired.

    Case, PSU and Environment

    No work yet.

    JPEG software

    Working - needs to be extended for colour. Needs speeding up too. Not hard.



  • The monochrome camera Module datasheets. We want PAL colour now.

    Camera Powerpoint DEC 04.

    Camera Powerpoint Feb 05. Camera PDF Feb 05.

    DTMF sniffer ht9170.pdf

    ADC ADC1173.pdf

    Hayes Modem

    Craft Port

    The CPU craft port is 4 pins at TTL level (power, ground, din, dout) for RS232 at 19200 baud.

    Initial Spec

    The initial spec is here LASHUP SPEC 1.


    Bill of Materials - BOM. Resistors and capacitors not listed.

    Note that no attempt has been made to consider temperature range outside 0-70 in the listed part numbers.

    All quantities are one off unless otherwise stated. The parts labeled AMG are available from the Audio Marketing Group in Haslemere.

    External Components

    Camera module - 5 Volt supply. PAL or monochrome composite video output.
    External wallwart mains adaptor : 24 V DC 500mA unregulated.
    Case/boxing/mounting lugs etc..

    Remaining components are mounted on the PCB 100x16 Eurocard.

    For the processor core:

    Matey PCB printed circuit board.
    H8S processor - H8S/2240. AMG. 100 pin.
    Quantity=two:Flash ROMs - MX 29F040C-55 or similar. AMG.
    Crystal 20 MHz. AMG. (or RS 370-438)

    For video capture:

    Socket for camera cable (RCA phono ?).
    FPGA from Xilinx - Part number TBD. Initially XC4005 or XC4006 for first small run.
    Framestore SRAM chips. 32Kx8 commodity part. E.G. CY62256LL-70SNC - Quantity three.
    ADC1173 - Video ADC. A single ADC is used for both lum and chrom.
    LM1881 IC synch separator. (RS 411-680)
    74U04 IC for XTAL osc if module not used.
    12.5 MHz XTAL
    SPU08P06P (RS 462-3398) - optional powerdown control transistor for the camera supply

    For the optional extras:

    Compact Flash socket, CPC part ref CN5037.

    For the power supply:

    LM2575T50 - IC - 5 volt switching regulator
    BYW99-150 - Diode Shotkey - PSU
    330 uH Inductor SMPSU
    1N5401 - Diode - Supply reversal protection
    Small 3V3 regulator for future FPGA (e.g. LP2981) and the ADC
    EMC choke/balun.
    7812 Regulator for +12 Volt feed to camera.

    For the POTS Hybrid Sub Assembly:

    P6KE12CA (RS 446-7564) Bidir Protection Semi 10Volt.
    Quantity four - EMC choke
    HT9170 DTMF Sniffer Chip
    3.58 MHz crystal (for HT9170 DTMF Sniffer Chip) (RS 249-3555)
    BABT transformer: E187A open (RS 210-6368)
    Quantity=two: Relays DPDT.24V 2057 RS 377-007
    Quantity=two: Solid state relays.
    Quantity=three. TL072 IC - Dual Audio OpAmp. SMS.
    Quantity=four: 2N7002 SOT23 N-channel MOSFET (RS 237-0907) Logic control transistors
    Quantity=two: PZT2907A Relay control power transistors
    Quantity=two: BAR43 Relay back EMF diodes.
    Quantity=three: status LEDs
    Line hold darlington transistor arrangement: PZT2222A SOT223 and BC817-40
    Quanity=two; DF02S (RS269-300) SMS bridge rectifiers (1A 200V)
    Instrument supply cicuit - auto polarity - ten transitors: PZT2907A times 2, BC817-25 times 4, BC807-25 times 4
    1N4001 - x4. Instrument supply.
    Off Hook relay: Part number COTO8343.


    Certain of the BC817 may be instead: 2N7002 VSIL SOT23 (17) N 0.11 7.50 0.20600 5 (RS 237-0907)

    The BB audio DAC is not longer used, all three DACs are now on the FPGA.

    Additional Information Required

    Availability of FPGA.

    Note that in the UK a 'master box' is needed before the phone will ring. The matey prototype discards any master box functionality on the exchange side and hence a master box must be installed between matey and the instrument for the instrument to ring.

  • UK Phone Wiring.