Digital oscilloscope

[Yves]

Hello all Pickster,
I just like to share something which I found very useful when you seal with protocols like I2C, Rs232 and others. I use to have an analogic (old type) analogic oscilloscope. It was always difficult to really see what is going on with all the jitters. I bought a "new" type oscilloscope that can fit in a pocket. The model is an entry type which is PicoScope (model 2000serise).The beauty is you can lock a digital signal and beside all normal oscilloscope functions, you can have table that gives you the address, the clock, the time, the nack or ack, the data packets, timing, etc. it has even a life reading of all bytes sent or received which can be saved in excel csv file. That made my life far easier when prototyping or testing all function after populating a new board. You can even generate a signal whatever voltage or frequency or form which can be used to feed the circuit. I'm sure all these are not news to you gurus but for me it was a complete game changing. It was also interesting to visualize how data are loaded from the PicKit 3. Tey are not even that expensive, the price rises in proportion with the maximum frequency. I'm sure there are many other types but I'm glad that I made the move to the 21th century.
All best,
Yves 

[Giuseppe]

Excellent choice the Picoscope. It also has the decoding of the sent protocol

[Stephen Moss]

Picoscopes are quite good, although I would recommened using fixed x10 or x100 probe with them to protect the input FETs as we used them at work for undergraduate teaching and had far more instances than we really should have of students blowing the obscure input FETs they use - you blow those out of warrenty and you may as well buy another as sending it to Pico for repair costs about the same.

Working theory was some kind on inductance in an AM radio reciever circuit running off 18V DC was cauing a voltage spike large enough to overcome the +/-100V overvoltage protection, I was not convinced of that personally.

[John Lawton]

IMHO that's really not good enough, having insufficient input protection.

[Yves]

Picoscopes are quite good, although I would recommened using fixed x10 or x100 probe with them to protect the input FETs as we used them at work for undergraduate teaching and had far more instances than we really should have of students blowing the obscure input FETs they use - you blow those out of warrenty and you may as well buy another as sending it to Pico for repair costs about the same.

Working theory was some kind on inductance in an AM radio reciever circuit running off 18V DC was cauing a voltage spike large enough to overcome the +/-100V overvoltage protection, I was not convinced of that personally.

Thank you Stephen, advice well taken
Yves

[GB1trude]

interesting information

[towlerg]

Hello all Pickster,
I just like to share something which I found very useful when you seal with protocols like I2C, Rs232 and others. I use to have an analogic (old type) analogic oscilloscope. It was always difficult to really see what is going on with all the jitters. I bought a "new" type oscilloscope that can fit in a pocket. The model is an entry type which is PicoScope (model 2000serise).The beauty is you can lock a digital signal and beside all normal oscilloscope functions, you can have table that gives you the address, the clock, the time, the nack or ack, the data packets, timing, etc. it has even a life reading of all bytes sent or received which can be saved in excel csv file. That made my life far easier when prototyping or testing all function after populating a new board. You can even generate a signal whatever voltage or frequency or form which can be used to feed the circuit. I'm sure all these are not news to you gurus but for me it was a complete game changing. It was also interesting to visualize how data are loaded from the PicKit 3. Tey are not even that expensive, the price rises in proportion with the maximum frequency. I'm sure there are many other types but I'm glad that I made the move to the 21th century.
All best,
Yves 

If you're looking to decode protocols I would suggest you look at clone Saleae logic analyzer and you don't even need to fell guilty about it as Saleae no longer sell that device (which by the way was a straight copy of the manufactures reference design).

[Dompie]

Yes I also use the clone Saleae logic analyzer and it is very easy to use and works well. And also Chinese cheap

Johan

[John Lawton]

I had a genuine Saleae Logic unit and lent it to someone....

Still I have a Siglent SDS1204X-E that has built-in decoding for various protocols and it works nicely.

I like using a 'scope as I can check for voltage levels, rise/fall times and glitches etc that the logic analyser probably wouldn't spot.

[towlerg]

I like using a 'scope as I can check for voltage levels, rise/fall times and glitches etc that the logic analyser probably wouldn't spot.

Sure but thats what you do when it's not working, not when you're decoding a protocol.