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New Oscilloscope

Jim FouchJim Fouch Posts: 395
edited 2013-07-20 09:15 in General Discussion
I'm looking at getting a newer scope for the ucontroller design work I do. I currently have two scopes; a 150MHz Instek GDS-820S http://www.tequipment.net/InstekGDS820S.html and a 200MHz Fluke 199c http://www.tequipment.net/Fluke199Cscope.html

I'm looking at replacing the Instek with a Rigol DS2202 200 MHz scope... http://www.tequipment.net/RigolDS2202.html

I guess my basic question is... will 200 MHz be quick enough for P2 testing and development? I'm guessing the quickest a P2 can flip a pin is 160Mhz with normal code. (I know using the timers, you could maybe go faster with a square wave, but I'm more interested in how fast a P2 can normally flip pins)

Not sure I can justify spending $3K - $5K to get a 350-500 MHz scope when I will probably never need to go that fast.

I also have a logic analyzer that captures up to 500MHz, but it only has a memory for 2048 transitions which makes it pretty limited.

I guess I'm just looking for some advice on if it's worth upgrading to a newer scope.

Jim Fouch

Comments

  • jmgjmg Posts: 15,173
    edited 2013-04-11 15:19
    The samples/s, and total sample depth, matter more than Bandwidth, and you might prefer 4 channels ?
    Seems to me like a lot of $$, for a small gain in specs.

    For a Logic analyser, build one with a prop 2 ??

    Also check if the claimed sample rate, is single shot, or repetitive (repetitive usually allows a higher more virtual number )
  • SRLMSRLM Posts: 5,045
    edited 2013-04-11 15:27
    Jim Fouch wrote: »
    I[/URL]'m looking at replacing the Instek with a Rigol DS2202 200 MHz scope... http://www.tequipment.net/RigolDS2202.html

    I     guess my basic question is... will 200 MHz be quick enough for P2 testing and development? I'm guessing the quickest a P2 can flip a pin is 160Mhz with normal code. (I know using the timers, you could maybe go faster with a square wave, but I'm more interested in how fast a P2 can normally flip pins)

    I bought a 200MHz Agilent scope like new off Ebay for $600+50s&h. It was a bit nerve wracking, but when I finally got it I discovered that it is in excellent condition, and I have no regrets. I'd suggest doing something similar.
  • Jim FouchJim Fouch Posts: 395
    edited 2013-04-11 15:31
    One of the things I was looking at was not so much the faster scan rate, but many of the functions that have been added over the last several years.
  • evanhevanh Posts: 15,943
    edited 2013-04-11 16:03
    The Rigol is the only one of those three with enough capture memory. No need to go beyond 200MHz analogue bandwidth. I'd highly recommend moving up to four analogue channels though.
  • ComputeruserComputeruser Posts: 16
    edited 2013-07-10 18:58
    You may have already made your decision, and I just found this forum this past week. In any event, I recently got an Instek 2304A which is a 4 channel 300Mhz scope. It has good sample memory and good high speed sampling, so overall it does a decent job.

    ....C
  • Jim FouchJim Fouch Posts: 395
    edited 2013-07-10 20:10
    Actually, I ordered the Rigol DS2072 70Mhz scope today. I have been watching the forums on eeVblog and some people have been able to open the scope up to 200MHz.

    I currently have a 150 Mhz Instek I bought about 6 years ago that is getting a bit old in the tooth. I guess these Rigols have been pretty popular. They are on about a 4 week back order.
    Computeruser wrote: »
    You may have already made your decision, and I just found this forum this past week. In any event, I recently got an Instek 2304A which is a 4 channel 300Mhz scope. It has good sample memory and good high speed sampling, so overall it does a decent job.

    ....C
  • ComputeruserComputeruser Posts: 16
    edited 2013-07-11 05:14
    I am a member at eeVblog as well and have gone through most of the videos by now. I think both Rigol and Instek have made good machines worthy of their marketplace. That comes out in eeVblog.

    I think, but I am not certain, that Rigol closed the door to software upgrading to a higher bandwidth. In any event, I am sure you will be happy with your Rigol purchase.

    ... C
  • tomcrawfordtomcrawford Posts: 1,128
    edited 2013-07-20 09:15
    This isn't actually a real 'scope; it's a eight channel, 24 MHz USB logic analyzer. The software is well crafted, very intuitive, and the price is right. I can remember when this capability would have cost a year's salary. 24 Mhz is plenty fast for BS-anything or for Spin. Plenty of capture depth before and after trigger and if eight channels aren't enough you probably aren't looking at the right ones. tc

    http://www.saleae.com/logic
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