$5.00 simple oscilloscope using Picaxe and VB


Patrick Cambria posts this simple oscilloscope project using a Picaxe-08M microcontroller and a potentiometer. The Picaxe is programmed in BASIC and the entire MCU program follows:

main:
READADC10 1,B0
SERTXD(#B0,10)
goto main

The output from a potentiometer voltage divider is fed into an ADC pin of a PICAXE 08M then serially transmitted to a Serial Port in Visual Basic.NET and plotted over time in a line graph. (Patrick also notes you can also use a bar graph for a nice visual effect!)

For links to the schematic and Visual Studio source code visit Patrick Cambria’s website.

This entry was posted in code, oscilloscope, PICAXE and tagged , .

Comments

  1. Arup says:

    Nice. I guess the VB application can be used with other MCUs’ UART outputs too.

  2. Xykon says:

    That picaxe provides rs232 serial output?

    • Sleepwalker says:

      Yes, but it’s at 5V level (or whatever voltage the PIC is running at). Most serial ports will accept the 0 – 5V signals back from the picaxe, however if running off a lower voltage, some serial ports might not recognise the levels – easiest thing is just try it and see, you won’t hurt anything. Obviously this is only good for short lines, not great long distances.

  3. Lasse says:

    Nice, is the vb source available?

  4. Yes the entire VB project is available on my website. You can port the project to any serial communication. If you are a picaxe user and you serout to an LCD and can instead sertx to visual basic. In my application im only looking for integer values so you have to change the data types to deal with strings but anyone who knows the basics of programming can switch it around.

  5. Mark says:

    Hi Patrick,

    If you are using READADC10, then surely you should be using a WORD variable for the 10bit value?
    Good presentation. :)

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