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Tiva- Connected Launchpad DSO Here is a beginners version of an Oscilloscope and Network Analyser, using the Connected Launchpad as digitiser and a modified version of the CircuitGear Mini Graphic User Interface of Syscomp Electronic Design Ltd. www.syscompdesign.com. Spec’s: 1 channel differential @ 4 Msps or 2 channel diff. @ 2 Msps max. The 12 bit ADCs sample always at 2Msps, on lower required speeds the signals are oversampled as much as practical for an output of 14 bit unsigned integers. This makes aliasing-filtering easier. The timing is entirely done by the ADC-clock. The software is made with "Energia version 0101E0012" ; thanks for this "easy to start with" tool. and with the wiring_analog.c from https://github.com/vladn2/Energia/ . (this one does not use interrupts). There are many comments in the code to explain the workings. There are timing problems while using Energia version 0101E0013 even with the new pde.jar for optimisation. With a AD9850 direct digital synthesis (DDS) as sine-wave generator, output frequency resolution of 0.0291 Hz with a 125 MHz reference clock. This is based on: http://forum.stellarisiti.com/topic/558-ad9850-with-energia/ CircuitGear GUI modification. The offset (new in vertical.tcl) and Gnd-shift (in cursors.tcl) is now handled in the GUI (display.tcl), not in hardware. In display.tcl is channel C embedded as product of chan.A and B for power measurement. Change of the vertical settings or the cursors ends in a re-plot of the screen with the old data for further investigation. For the trigger-modes and options are buttons used, very handy especially for Single-shot to quickly stop acquisition when a freak signal occurs (the menus are still there). The Single-shot mode now also functions in the scan-mode, so that acquisition stops at the end of the screen. While developing, it became necessary to add a ‘disconnect, item to the hardware menu. The Waveform Generator GUI sends its frequency value as one big number to the LaunchPad. Amplitude and offset are not used (yet). In the Network Analyser mode the logarithmic frequency settings and the right plot limit are changed and the ‘End Frequency’ is as measurement step added. The logarithmic steps are now set by the number of steps per decade. To implement these changes, install the GUI from www.syscompdesign.com. Than rename the original tcl-files in the source-directory that must be replaced by the modified ones and copy the modified versions in the source-directory. Also copy the two images (these were necessary to better fit my screen) in the Images-directory. Future plans: Build the analog part. Implement amplitude setting on the DDS. Implement a Hi-Res-mode by using a longer circular buffer. Tiva-DSO and GUI modification.zip CircuitGear display.zip
