Major Update: Digital Oscilloscope

The Alpha revision board It has now been nearly 2 years since the start of the USB Digital Oscilloscope project and it is still going strong!

You can see in the picture the alpha revision oscilloscope that has now been superseded. It was designed in Eagle and consists of a 2layer PCB with a Xilinx Spartan 3AN FPGA, DDR SDRAM, Maxim ADC and Cypress FX2LP.

We went for a modular design in the end with separate input boards and USB board. This makes the system easier to debug by isolating different systems and makes it cheaper if any components need to be redesigned. We were very luck that there were very few mistakes in the PCBs so we only had to make one or two fixes.

Due to hardware restrictions (mainly the FPGA not being able to contain all the code) this design has now been retired and a new version is in the design process. The updated version now has a Spartan 6 FPGA at the centre, DDR3 memory, a 1GSPS ADC and Cypress FX3 which will provide SuperSpeed USB3 communications.

After deciding that the project could no longer be implemented on a 2layer PCB and the Eagle Free version only supports 2 layers, we had to look for other software. After doing some work experience with an electronics company, I was lucky enough to have a play with Cadence Allegro. I found that Altium Designer (a very similar product) seem to support a few student projects so I thought it was worth a try emailing them. Several weeks later I managed to score a year-long Altium Designer licence with an Altium Subscription free of charge! The acquisition of this software has meant the design process is a lot faster and easier, but understandably we cannot use the licence for commercial use.

I will post again soon (he says after not posting for 2 years!) with more HW&SW details and hopefully all the schematics.

Wednesday, April 25th, 2012 Electronics Projects

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