Electronics Projects

Digital Oscilloscope Design Files

The Alpha revision boardThe other day I said that the original oscilloscope hardware has been retired and a new version is in the design process. Below I have documented all the parts of the original hardware and have attached the schematics, board files and code.

› Continue reading

Wednesday, May 2nd, 2012 Electronics Projects 4 Comments

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You can see in the picture the alpha revision oscilloscope that has now been superseded.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 No Comments

Update: Digital Oscilloscope

It has been a long time and there have been several significant progressions!…

We has scraped the idea of using a PIC and are now using an FPGA that can run a lot faster, SRAM as a data buffer, a Cypress FX2 high speed USB controller and a whole host of analogue circuitry with multiplexers. We are still using the same ADC however. That part of the plan hasn’t changed!

We are currently finalising schematics, then will send the PCB designs off to be manufactured.

The end is in sight! This has turned out to be a project that has given us a vast amount of new knowledge. Now it’s time to share it!…

Monday, October 18th, 2010 Electronics Projects No Comments

Update: Digital Oscilloscope

Just a quick update on the progress of the scope.
One difficulty we are finding is getting everything to work fast enough! We need a microcontroller that operates at 100MHz minimum to cope with the data throughput from the ADC! We are thinking of maybe using an ARM processor, as no PIC uC can cope with those speeds, but we haven’t decided yet.

This is turning out to be a challenging project!

More updates to follow soon.

Wednesday, August 4th, 2010 Electronics Projects No Comments

Project: Digital Oscilloscope

Over the summer my electronics buddy Ali and I are building a 2 Channel 100MSPS Digital Oscilloscope.

The project is still in it’s fairly early stages but some details of the design so far follow:

It will use the MAX1198 ADC and MAX4105 op-amps

The MAX1198 samples the two input signals at 100MSPS at a resolution of 8bits.

The data will be filtered and buffered before going through the ADC and then the parallel output of the ADC will go into a PIC18F4550 to be sent through USB to a host computer.

More updates will follow soon, hopefully with some schematics and designs.

Wednesday, July 28th, 2010 Electronics Projects No Comments