Digital oscilloscope Project

[nsakan]

homemade digital oscilloscope

Gonzakpo asked a question about having higher voltages than maximum ADC input

> The idea is to suply an operational amplifier (OP) between the adc input maximun
> voltage ranges....
> For example between +0.5V and -0.5V.... (maximun input voltage range of my adc is > 1Vpp)
> Also, configure the GAIN of the OP to 1. (A=R2/21)

Please look at the atached png figure area A abd B between 2 and 3

You coud see an easy solution for Your problem, use two clamping diodes, they must be atached to the supply pins of the devices that You have to protect. Also it could be advisable to have some resistance beween X1-1 and diodes, jut in case that ne overvoltage is not spike but constant signal, like in Your case.. Lot of modern opamps have protection diodes inside of them, please reas the datasheet of both opamp that You would like to use and AD converter carefuly. Also be careful not to slow down the AD convereter input with the slow opama. When You are looking for the opama characteristics, note the the bigest frequency at which Your opamp is capable to delivet 1Vpp swing (for exmple the lrgest frequency tht You coud cheeve with OP07 is something between 60kHz - 80kHz, pg. 7 of OP07C Analog evices datasheet fig. TPC17). It is most likely thay Your ADC have the protection diodes inside of it, and the simplest solution is just to add some resistance in front of it. With such meho You cou hve higher voltages than opamap +/- supply voltage applied, the higher voltages would be cutt-off. Try to make some auxulary supply with nice capacitance, not only big but with low ESR and combination og several types of capacitors for Your cllamp diodes that would keep them on +0.5V and -0.5V, but first carefly reed ADC datasheet and find some aplication notes for it.

I might have some time on weekend, so if You would like send me more details about ADC and I will try to tell You something more.

Sincerely Yours,
Nenad Sakan

 

[miki.krejci]

schematic of oscilloscope

Hallo everybody,
I want to made USB oscilloscope with using FT2232C. Sampling rate about 1Mhz. I want use 12-bit A/D converter. Have you somewhere seen some scheme with input circuits? I do not know how do to range changed automaticly or how can I control range with using two bits.
Thanks for help!

 

[alphi]

area26 dso

I use TLC5540 for my home DSO,but TLC5540' min sample rate is 5MHZ.So if i need low sample rate(example 100KHZ),how can I do with it.
my systerm:TLC5540+XC9572+MCU

 

[dainis]

fpga vga oscilloscope

I use TLC5540 for my home DSO,but TLC5540' min sample rate is 5MHZ.So if i need low sample rate(example 100KHZ),how can I do with it.
my systerm:TLC5540+XC9572+MCU

Skip some samples, sampling on 5MHz and use each 50 sample ?
Or use signal averaging by software ?

 

[alphi]

tda8703 a/d oscilloscope

if I use 5HMZ for TLC5540,and use 50 sample for one data,then i can get 100KHZ sample rate.but it will make memory deepth become very small,if I have 128Kbyte sram,and i can only use 128Kbyte/50.

 

[computer_engineer]

pvt312+application

any one can help me plz? i want to know if ubicom ip2022 accept sinesoidal signal? i need to measure voltage and current signals an calculate real power.

Added after 5 minutes:

i need ur help quickly plz. any one can help me. plz peply me quickly. my project raquire measuring voltage and current of each home and calculate apower consumpsion. i need to know does the ubicom ip2022 adc accept sinesoidal signal. if does not what is the solution???????????????? plzzzzzzzzzzzzzzzzzzzzzzz

 

[mayo123]

glcd avr

Hi everybody,

After more than a month of rest, here is the 6th revision of the DSO (register to see the schematics):

http://164.15.88.56/site.php

Regards,

I try some weeks, but the site in down.

Has any a copy of this site ??

Thanks.

 

[rashslash]

fpga oscilloscope

well use tlc549 serial 8 bit adc from texas instruments and use the parallel port

 

[computer_engineer]

scope or oscilloscope schematics

hi every one .... ineed ur help
i use UBICOM ip2022 as afield unit and i heve to calculate the real power consumption of a house i used 2 channels of ubicom ADC and fed voltage to one channel and the current to the other channel.. i rised the voltage and current level by arrefrence voltage becoz i don't know if UBICOM's ADC accept negative voltage or not and i multiplyed each voltage sample by current sample over aperiod and then diveded the accumlation result by the no. of samples did i use acorrect method plz help meeeeeeeeee

 

[adidex]

best firewire oscilloscope

Are you sure ?

The archive contains the schematics, PCB and the byte-files needed to program the microcontroller and the cpld: eoscope_1.2.zip

h**p://www.mindbend.ro/eoscope/download/eoscope_1.2.zip

good luck

Yes I am preety sure....The files are in compiled form. No source code is provided.

Hello,

We decided to public the sources of the project in the meantime, so now enybody should be able to make changes in the code.

We have also posted some other projects on a new site, www.eosystems.ro , the old web page (that one on the mindbend.ro domain) is obsolete and will be removed soon. I hope you can find some interesting projects on the new site, unfortunately our time is very limited so the updates on the site will not be very fast, but we have some projects wainting to be published.

So .. enjoy, and please send us some photos if you build some of our projects, and maybe send us the code too in case you make some changes, so that we can publish them on the site (hmmm .. maybe a new LCD interfacing is a good idea, or a PC connection ;-) ).

Adrian & Daniel

 

[CMOS]

max1180 schema

Hello,

We decided to public the sources of the project in the meantime, so now enybody should be able to make changes in the code.

We have also posted some other projects on a new site, www.eosystems.ro , the old web page (that one on the mindbend.ro domain) is obsolete and will be removed soon. I hope you can find some interesting projects on the new site, unfortunately our time is very limited so the updates on the site will not be very fast, but we have some projects wainting to be published.

So .. enjoy, and please send us some photos if you build some of our projects, and maybe send us the code too in case you make some changes, so that we can publish them on the site (hmmm .. maybe a new LCD interfacing is a good idea, or a PC connection ;-) ).

Adrian & Daniel

Thats great news. Thanks !

 

[bamdad]

homemade dso

Dear All;
Is there anyone who knows how to implement a reconstruction algorithm for equivalent time sampling? besides, all the input protection methods I see around, relies on two diodes to supply rails to protect the sampling device, this has two draw backs, in high freqs, the diode capacitance will limit the signal bandwidth (specially when the series resistor comes between the diodes and the sampler), and this is not a linear effect, since the diode capacitance varies quite much with the reverse bias voltage... another point, this protection stage changes the input impedance of the sampler when it is clipping... does anyone know a better protection mechanism for a high speed oscilloscope, say, something about 100MHz?

 

[pmhunt]

digital oscilloscope with fpga

try to use gameboy for small oscilloscope

I am currently developing a circuit that uses the Gameboy advance to take samples of upto 100Msps

using a fifo and CPLD

www.cardiagnostic.co.uk/gbadso.htm:arrow::arrow::arrow:

 

[Nick18]

+minik0bo +oscilloscope

Hi everybody,

After more than a month of rest, here is the 6th revision of the DSO (register to see the schematics):

http://164.15.88.56/site.php

Regards,

I try some weeks, but the site in down.

Has any a copy of this site ??

Thanks.

I'm asking the same. How about this project? Project obosolete?

 

[Vacuum]

digital osilascope schema

Hello dear all.
I also develope my scope. In my plans to make it more versatile:
First of all in my plans to make programmable attenuator. But is seems too difficult... So it would be wonderfull to use ready made. Whether there are suppliers of P.A. on market?
Second: protection of overvoltage.
Third: to make RIS mode. With it I can observe periodical signals of very high frequency. Is it possible realize in fpga?
Many thanks!

 

[miniK0bo]

fpga osciloskop

hey all,
I also was thinking about building a DSO. I came across this topic and notice the similarities. So far I've split my design in two parts. Digital part with FPGA, SDRAM and USB2 interface. Analog part with 100MHz ADC and FIFO. The digital part I finish building it (see attachments). I still need to start the analog part (/me not so good in analog). I was wondering what the status is of the design, did any build it yet?

 

[judasdsc]

hombrew digital sampling oscilloscope

seems good. Do you have web site about this project? Any schems?

 

[miniK0bo]

tdc implemented on cpld

sorry no website yet, I could post the schematic one of these days

 

[picnoobie]

stroboscopic oscilloscope schematic

EDIT: how stupid of me, the link I posted was in the first page of this thread, I just accidentally landed on this thread during my search and didn't read up in the begining. I apologize.

 

[miniK0bo]

pc-oscilloscope kit circuit

as promised: the schematics
so far there is one mistake in the schematics. the reserved pin on the fx2 chip needs to be grounded!