LCS-1M - A Low-Cost Hobby Oscilloscope
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The microcontroller firmware is the program that runs on the Picaxe microcontroller and which controls
the scope hardware. It communicates with the PC-based user interface through the serial port. It is
written in Picaxe Basic, which is a simple version of Basic geared towards the capabilities of this
microcontroller. Below you find the full source code which you can modify to your liking, or just browse
to see how the scope is driven.
You can buy a pre-programmed microcontroller from this website, but it is really easy to burn your own
(see the "Build It" tab).
Rev-Ed recently released the X2 series of their Picaxe microcontroller (it was a long wait - originally
announced two years ago!). Compared to the Picaxe 28X1 the Picaxe 28X2 has a number of cool new
features, among them higher maximum clock speed (40 MHz vs. 20 MHz) and the ability to also invert
the hardware serial receive pin - this allows to get rid of the MAX232 interface and replace it with a
simple interface.
The moment I got a hold of the Picaxe 28X2 (thanks to Rev-Ed for the free development samples!) I
went and implemented a number of improvements in the firmware, PC software, and hardware. A
detailed description of the necessary hardware changes is on the Upgrade page. You need to use the
new version of the PC software together with the new version of the firmware in order to run the
modified scope!
Old firmware (for scopes using Picaxe 28X1 and MAX232 interface):
New firmware (for scopes using Picaxe 28X2 and simple resistive interface):
To download the Picaxe microcontroller programming editor (needed for the firmware download),
please visit the Revolution Education website.
I discovered that the MAX232 is introducing significant noise into the scope signals so even if you
don't need the increased screen update rate the new version provides I still highly recommend
upgrading your scope!
the scope hardware. It communicates with the PC-based user interface through the serial port. It is
written in Picaxe Basic, which is a simple version of Basic geared towards the capabilities of this
microcontroller. Below you find the full source code which you can modify to your liking, or just browse
to see how the scope is driven.
You can buy a pre-programmed microcontroller from this website, but it is really easy to burn your own
(see the "Build It" tab).
Rev-Ed recently released the X2 series of their Picaxe microcontroller (it was a long wait - originally
announced two years ago!). Compared to the Picaxe 28X1 the Picaxe 28X2 has a number of cool new
features, among them higher maximum clock speed (40 MHz vs. 20 MHz) and the ability to also invert
the hardware serial receive pin - this allows to get rid of the MAX232 interface and replace it with a
simple interface.
The moment I got a hold of the Picaxe 28X2 (thanks to Rev-Ed for the free development samples!) I
went and implemented a number of improvements in the firmware, PC software, and hardware. A
detailed description of the necessary hardware changes is on the Upgrade page. You need to use the
new version of the PC software together with the new version of the firmware in order to run the
modified scope!
Old firmware (for scopes using Picaxe 28X1 and MAX232 interface):
New firmware (for scopes using Picaxe 28X2 and simple resistive interface):
To download the Picaxe microcontroller programming editor (needed for the firmware download),
please visit the Revolution Education website.
I discovered that the MAX232 is introducing significant noise into the scope signals so even if you
don't need the increased screen update rate the new version provides I still highly recommend
upgrading your scope!