SM2000 Part 6 – PCB Layout

Since the last post in this series Rick, KA8BMA, has been working steadily on the CAD work for the SM2000 VHF Radio. We now have the SM2000 schematic and 80% of the PCB layout is complete. Rick has taken a modular approach, laying out each building block that I prototyped last year.

Here is the current state of the PCB layout, which is 160mm x 160mm

On the waveform side, Brady, KC9TPA, has done a fine job porting a 4FSK modem to C and developing two new VHF FreeDV modes. ModeA is an “optimal” 4FSK mode that runs at 2400 bit/s, has a 5kHz RF bandwidth and a MDS of -132dBm. ModeB use Manchester-encoded 2FSK at 2400 bit/s and will run over any FM radio, even $40 HTs.

Brady’s modem is also being used for our high speed balloon telemetry work.

There is plenty of software work (e.g. STM32F4 micro-controller code) to be done for the SM2000. Help wanted!

Links

SM2000 Part 1 – Introducing the project

SM2000 SVN – CAD Files for the project

3 thoughts on “SM2000 Part 6 – PCB Layout”

  1. Hi All,

    PCB looks VERY nice :).

    I would suggest bigger and more modular. Especially at first. So that I can use parts of the design and
    more or less easily insert my own external parts and import and export signals and power in and out.

    For example, PIC32MZ…EF has a very fast ADC. Can I patch my PIC32 kludge into this PCB with relative ease?

    Most designs seem to be obsessed with smaller, giving up ability to easily modify them without microscopic skills :).

    You can guess what my PCBs look like :).

    Lots of fun :).

    John

    1. Hi John,
      PIC32MZ EF are beautiful chips but they lack DACs, which will mean an extra IC to this design.

  2. Hi Alex,

    Or just using something else as the DAC. WebSocket to a cheap wifi phone for example.

    The phone can also be a front panel, etc. Lots of goodies for very low $$.

    I have yet to figure out how to generate WebSocket on my website? But the originating side

    of WebSocket is pretty simple and seems to work well here. I see there is now even a

    WebASM.js. Which claims to be only slightly slower than assembly! [ I REALLY doubt that !! ]

    As I am SURE most readers of this site do :).

    FWIW – websdr seems to use WebSocket. I still haven’t figured out his code! So if you have

    used websdr, you have already used WebSocket :).

    Lots of fun :).

    John

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