Jabberwocky is an acronym for Just Another Big Bandwidth Event Recorder With Oscilloscope Capabilities.

It is a combination of hardware designs and software that uses an ASIC switched-capacitor-array AtoD converter to make a handheld, battery/usb powered, 2 channel oscilloscope with an organic LED display.

Development on the oscilloscope was started in January, 2008. A design was finalized and a board was fabricated in May of that year.

overview

The oscilloscope is battery (rechargable LiPoly) or usb powered, has 2 channels of input (DC coupled only), has a 128×124 pixel full-color OLED display. It supports (slightly) advanced triggering or an optional trigger-delay.

The input impedance of this scope is 1MOhm. The analog bandwidth is unknown at this point (and will be until the project is nearly complete). The lab3 can sample billions of times per second, but this oscilloscope will probably only be useful at a much much lower sampling speed. This is due to the choice of input amplifier and multiplexer: The multiplexer has a bandwidth of about 700MHz as does the voltage-feedback operational amplifier.

still to to

At this point, there is some preliminary software running on the device to capture a trace with the microcontroller’s onboard AtoD converter and display it and allow selection of vertical scale, vertical offset and horizontal scale. Software to control the external trigger-delay has been written and tested.

Further software must be written to get data from the lab3 and control the DACs. After that is complete, bandwidth & slew-rate testing will be carried out and presented here.

(The current status is not yet ready for end-user use.)