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Does a hobbyist need a Oscilloscope?

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ebclr:
A scope is a must have, but not at early stages, You will improve your knowledge exponentially after the scopes start to be used

suicidaleggroll:

--- Quote from: tggzzz on June 23, 2016, 10:27:05 pm ---
--- Quote from: suicidaleggroll on June 23, 2016, 07:16:56 pm ---If you're doing digital/MCU work, I think a logic analyzer is far more valuable than a scope.

With a scope: "Yep, it's sending something"
With a LA: "Oh crap, the 57th byte was 0xFA when it should have been 0xFE" *find and fix firmware problem on MCU*

--- End quote ---

With LAs you have to be sure that the LA is interpreting the analogue signal in the same way as the circuit's receiver. Problems can arise with different thresholds, especially with the probe leads, and with setup/hold time variations.

Those problems are worse with modern logic families, and it is notable that nowadays LAs are relatively  little used for professional electronic systems.

--- End quote ---

Scopes are used for investigating analog problems (noise, voltage levels, and other layout or component selection problems), LAs are used for investigating digital problems (communication errors, timing errors, and other firmware issues).  While he can, and likely will eventually have analog problems on a digital circuit, such as the issues you mentioned, incorrectly sized pullup resistors for I2C, etc., for a beginner he is FAR more likely to have digital/firmware/communication problems, and a traditional scope will be next to useless for those.  Ideally he'd have both, but for a beginner getting into MCUs, a LA will be far more useful IMO.

tggzzz:

--- Quote from: suicidaleggroll on June 24, 2016, 02:39:03 pm ---
--- Quote from: tggzzz on June 23, 2016, 10:27:05 pm ---
--- Quote from: suicidaleggroll on June 23, 2016, 07:16:56 pm ---If you're doing digital/MCU work, I think a logic analyzer is far more valuable than a scope.

With a scope: "Yep, it's sending something"
With a LA: "Oh crap, the 57th byte was 0xFA when it should have been 0xFE" *find and fix firmware problem on MCU*

--- End quote ---

With LAs you have to be sure that the LA is interpreting the analogue signal in the same way as the circuit's receiver. Problems can arise with different thresholds, especially with the probe leads, and with setup/hold time variations.

Those problems are worse with modern logic families, and it is notable that nowadays LAs are relatively  little used for professional electronic systems.

--- End quote ---

Scopes are used for investigating analog problems (noise, voltage levels, and other layout or component selection problems), LAs are used for investigating digital problems (communication errors, timing errors, and other firmware issues).  While he can, and likely will eventually have analog problems on a digital circuit, such as the issues you mentioned, incorrectly sized pullup resistors for I2C, etc., for a beginner he is FAR more likely to have digital/firmware/communication problems, and a traditional scope will be next to useless for those.  Ideally he'd have both, but for a beginner getting into MCUs, a LA will be far more useful IMO.

--- End quote ---

Your overall approach (1: signal integrity, 2: logic) matches mine, but I've always found it possible (even easy) to debug the kind of "logic" problems you mention with a imagination, a scope plus for(;;){} and printf statements.

Whether an LA with MCU will be sufficient depends on what the MCU is being used for and how it is constructed. I think I'll shortly do a "teach in" where I get people to make a logic circuit on a solderless breadboard - with long leads and no decoupling. That'll teach 'em there's no such thing as a digital circuit :)

Only last night someone came to me with "when I switch the heater on, the USB link loses sync". Clearly switching (he thinks) 0.5A is causing EMI problems. Given there was only 5 minutes and he didn't know whether his PSU output was earthed or floating, we didn't have time to investigate it.

janoc:

--- Quote from: tggzzz on June 23, 2016, 10:27:05 pm ---Those problems are worse with modern logic families, and it is notable that nowadays LAs are relatively  little used for professional electronic systems.

--- End quote ---

All that is true, but then you also have a fancy mixed signal scope that will do that decoding for you, when needed, effectively replacing that LA.

For us mere mortals a LA is a must, because, even though my Rigol has serial decoding, it is fairly basic and pain to use.



System Error Message:
after getting my scope all i can say is if you are into electronics you definitely want a decent one. Even if you dont use it it will make an awesome interactive toy/decoration.

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