DIY external serial monitor


ARPix  wrote this Instructable detailing the build of his DIY external serial monitor:

Sometimes I needed an external serial monitor like the Serial Monitor in the Arduino Editor, to see what is going on. So I made one. The first picture shows an example how could be it designed.

For the ESM I used an Atmel Atmega328 (based on the Arduino-Board) because it have an internal SRAM with 2KBytes. It’s necessary for the big data processing.
So you need more than 1KByte SRAM.
With the menu in the ESM you can do…
… setting the baud rate
… start and pause the reading

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  1. Here is my take on the same thing:

    Board/screen pics

    and here it is in action: image

    as you might just be able to see on the PCB pic – it’s also an atmega328 with 2k of ram, stuck to the back of a 2.8″ tft with resisitive touch layer. Made only a small mistake with the folding of the flatcable – there are some SMD components on the flatcable that I didnt really leave a space for…

    I’ve used it in combination with our protoboard to debug some MIDI and serial stuff so far – maybe I’ll add some small FPGA later to analyse more interesting protocols :-)

  2. Anyone know of a 4.3 inch monochrome LCD, with 800×480 resolution? Touch screen not required.

    I’m feeling inspired.

  3. I’ve been doing something similar using my Galaxy S3 with USB-OTG hooked up to a usb serial adapter and a program called “Free USB Serial Term”.

    Works great.

  4. I don’t think I’ve ever seen 800×480 LCD monochrome. Colour 800×480 are at least 5in, and cheap panels need the whole RGB drive thing, while MCU interface versions are expensive…
    Actually 800×480 is overkill for most debugging. For me, a 96×64 (16×8 lines) Nokia 1100 or 1202 LCD is a huge improvement over a 16×2 alphanumeric LCD. Plus a small monochrome LCD will only take maybe 100-200uA of power, while a 800×480 will use a lot of power.

    1. I asked for 4.3″ because that’s mobile phone [iPhone?] size. 800×480 helps smooth fonts, increase legibility. My eyes aren’t so young – I need a bigger screen to read comfortably.
      Restricting to mono would keep power down, and limit the RAM required to about 47KBytes.

      Sticking with Atmel? I’d consider the AT32UC3A1256 [or 3128]. Once you leave monochrome, youll need a different chip – or external RAM.

  5. That is sensible… there are 5in and 5+in TFT color panels from China/HK with MCU interface, but they can cost as much as a second-hand LCD monitor… There is Pixel Qi, part mono, dunno if they are still selling, but I think the interface is RGB, more difficult to work with.

    Another panel tech that might be better than a mono panel is an e-ink display, which has better contrast in varied lighting conditions. Seeed Studio has/had a couple of e-ink panel sizes (saw a 2in just now) and an interface board. I dunno if they are big enough for your use… but I have talked before to the suppliers (Pervasive Displays) and they have panels up to 4.4in.

  6. Before I forget, here’s another idea… there are also plenty of e-ink boards on Alibaba that are supposed to be used for e-book devices, and there are driver chips being mentioned, but I’ve never seen any data sheets for the driver chips published online, or anyone tackling the task of interfacing to these boards. Just a thought.

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