Why not handle communications, I/O selection, leds, etc. from the FPGA instead of adding a µC? It should be possible to program all these functions into an FPGA. If you want, you can even get a complete µC IP-core to implement in a part of the FPGA and then program it as a normal µC.martingn said:... a DSO should have to be implemented with a uC (communications ,I/O selection, leds, etc..) You can use that uC to program the FPGA each time. ...
Read this link about FPGA configuration:monnoliv said:martingn, Concerning the ACEX 1K EP1KX0, if I've well understand the strucure of this device, it must be configured at each power on. How doing this with embedded processor, EEPROM? Do you have a schematics ?
FPGA configuration
An FPGA can be into 2 states: "configuration mode" or "user mode". When the FPGA wakes up after power-up, it is in configuration mode, sitting idle with all its outputs inactive. You need to configure it.
Configuring an FPGA means downloading a stream of 0's and 1's into it through some special pins. Once the FPGA is configured, it goes into "user-mode" and becomes active, performing accordingly to your programmed "logic function".
There are 3 classical ways to configure your FPGA:
You use a cable from your PC to the FPGA, and run a software on your PC.
You use a microcontroller on your board, with an adequate firmware.
You use a special PROM on your board, connected to the FPGA, that configures it automatically at power-up (FPGA vendors have such special PROMs in their catalogs)
...
I have already uploaded an article from Elektor with a Gameboy based DSO:eltonjohn said:Hi Guys ..stand alone ..hein !
Well the Gameboy has a 240x160 .32k colors display . is very cheap around $90 brand new .. can be found for $25 used .. graphic modes used DMA .. and can be very fast .. on top is very easy ,,very easy to adapt an interface ..is just a matter to map to the memory espace space avalaible for the ROM cartridge .. and there are nice tools to quickly make a nice graphical interface .. see .. VISUAL HAM ..(! free) !
monnoliv said:Thank you for your comments,
Thank ME for the link.
martingn, in fact I use P*otel DXP Educationnal licence, then it will be difficult to exchange schematics. But anyway thanks for your tip, I'm thinking to take this kind of solution:
- inputs stage and ADC unchanged.
- analog triggering deleted
- ACEX1K10 or 30 for the logic, FIFO and triggering (+boot, have to see)
- one (cheap) µC
- USB controler + supply + insulation unchanged.
I think that this solution is the cheapest (with the same performance). I'm not seeking the best schematics, only the cheaper one, then accessible for a lot of hobbyist.
If anyone has a cheaper idea ?
Regards,
Thanks, I know about Bablefish, but the translation is not always accurate and some words are translated wrong, other words are not translated at all.simce said:A kind of translation from France and Italian to english can be done using altavista's translator. Use translation link on www.altavista.com.
Great site !The AVR is so fast that there have been made a 1.5 Mbps firmware USB interface for it: http://www.cesko.host.sk/IgorPlugUSB/IgorPlug-USB%20(AVR)_eng.htm
I'm not sure tiepie uses High-Speed because it's writen "USB 2.0 and USB 1.1" in the specs. Anyone has the price of the 100MHz/8bits version ?Here is a rather new commercial oscillospoe introduced last year, which uses USB2.0 for sampling frequency up to 100 MHz on both channels:
https://www.tiepie.nl/pages/uk/hscope3.html
So I guess USB2.0 will be good enough for the purpose and USB2.0 is standard on all new computers
Where in the schematics I've to put the pot? Can you put a small schematic ?May be DAC to calibrate input is too much, but at least you will need a pot!
I agree with you, I'm not an fpga expert too but putting all in an EP1K30 (too keep the DSO cheap) is optimistic for me. And then, what about the necessary insulation between PC and DSO ?Again, I not an expert, but, is this little FPGA (EP1K10) enought to do all? USB, IO Control, RAM ...
If 1kByte/channel is enough the 'IgorPlug' AVR firmware should be fast enough with 1.5 Mbps.monnoliv said:I'm not sure tiepie uses High-Speed because it's writen "USB 2.0 and USB 1.1" in the specs. Anyone has the price of the 100MHz/8bits version ?ME said:Here is a rather new commercial oscillospoe introduced last year, which uses USB2.0 for sampling frequency up to 100 MHz on both channels:
http://www.tiepie.nl/pages/uk/hscope3.html
So I guess USB2.0 will be good enough for the purpose and USB2.0 is standard on all new computers.
Anyway, full-speed is good enough if you have 1Kbyte/channel to transfer
Are you sure insulation is necessary?monnoliv said:I agree with you, I'm not an fpga expert too but putting all in an EP1K30 (too keep the DSO cheap) is optimistic for me. And then, what about the necessary insulation between PC and DSO ?Again, I not an expert, but, is this little FPGA (EP1K10) enought to do all? USB, IO Control, RAM ...
The Hanyscope 3 is powered from the USB port, which indicates it is not galvanic insulated unless they use an transformer insulated switched mode power supply for example with a flyback transformer. But maybe that is what they do.Connected to the fast USB 2.0, the Handyscope-HS3 doesn't require an external power supply, therefor the Handyscope 2 easily complies to "Plug in and measure".
Cypress looks ok, but if 1.5 Mbps USB is enough, why not use AVR, you can get it even cheaper? Maybe the AVR would be too slow if it has to handle a lot of other tasks besides USB, I'm not sure.monnoliv said:Anyway to continue the design, what is your opignion about the CYPRESS USB 8051 type processor (EZ-USB, 6.9 €) ? Cheap but the opto-insulation has to be done after the device...
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