Seeedstudio's 8bit oscilloscope?

Anyone have the 8bit hobby oscilloscope (in built or kit form)? Seeedstudio has put it on their “featured products” for November 2008. I am amazed at the price, but I don’t just want to throw money at it if it is going to be totally useless at TTL logic testing, such as Arduino experiments.

I took EE classes in college but all the Flukes were pre-digital, pre-storage types. I just got back into digital electronics (played with it when Parallax first came out with the Basic Stamp), but now that there are nice PCB prototype services, I want to go beyond the breadboard stage this time around. If this scope is any good, I’ll buy the first one and perhaps build another when I’m more confident that my solder skills are up to it.

There was a thread talking about this recently: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1223639021/0. I’m pretty interested in this too.

Mikal

After noticing my PayPal balance was higher than I remembered, I went ahead and ordered one from Seeed. I also grabbed some of those tiny Wii nunchuck breakout boards from FunGizmos.

Okay, received in the mail (finally). The Seeedstudio’s source is a company called JYE Tech, http://www.jyetech.com/ - thankfully with an English page as well.

Although this little oscope is no speed demon, it is surprisingly capable. When you unbox the unit, it’s even smaller than the pictures suggest. The whole thing is the size of two Arduino Duemilanove boards side-by-side. I got the preassembled form, which comes with a pcb faceplate and backplate to protect the internals better. This is probably a good thing, since I noticed at least one hand-patched revision to the oscope’s motherboard, and the kit form probably does not include written errata.

The probes are needle-tipped alligator clips, plugged in with a low-tech RCA jack. If left floating, you can see the signal stray by a few millivolts. If you touch both probes, you get a nice wavy 2Vpp biological signal. The unit has a tiny jumper wire you can clip that provides a test signal: a +5V square wave at 500Hz. They suggest you learn the functions with this test signal.

You can adjust the volts/div scale, the sec/div scale, and raise or lower the location of 0V in the view. This is a triggering storage scope, so there are three modes to display: free running (AUTO), refresh on every trigger (NORM), and freeze the display to show the first trigger (SING). The level required to trigger, and the direction of change required to trigger, are easy to adjust. For example, you can trigger on any downward change through +3V. The scope will show 256 samples in the vicinity of that trigger point. You can shift the view to focus on more of the time before or after the trigger moment.

The only real downside is that the display can only update at about 2~3 frames per second. I’m sure it’s due to the LCD driver that they chose. If you hit OK, the screen will HOLD the current contents of the sample buffer (which is always newer than what you’re seeing). If you’re in NORM mode, this means you can freeze the screen to study a packet of data as it goes by, but due to the update lag you might expect you can see a signal of interest and hit OK to freeze it. You can’t.

Oh, and a pleasant surprise: it seems to store your selection preferences in nonvolatile memory, so it starts up again with the same time and trigger settings you used last time.

With these features, it was pretty easy to study the i2c conversation between a Wii nunchuck and the Arduino. From the source code, I knew that the first byte of all command packets was a constant 0x52 so this should be an easy pattern of 1s and 0s to spot on the line.

There’s also a frequency-counting mode which I have yet to try. It was hard enough tearing myself away from the fun i2c study that I was doing to take a photograph, but now I’m off to see what a PWM-to-audio waveform looks like.

Wow, ed, how about conducting a seminar in taking attractive electronics photos? That’s really nice. I’m sure Seeedstudio or NKC would like to use it. :slight_smile:

That’s really nice. I’m sure Seeedstudio or NKC would like to use it.

Thank you, mikalhart. They’re welcome to them. The photos I’ve been collecting in my http://halley.cc/arduino area are released Creative Commons (Attribution Only). The -small variants seem to be missing the embedded comment but they’re on the same basis.

What kind of camera, lighting and settings are you using?

Those pictures look great! :slight_smile:

Impressive! Count us in for the photo seminar… ;D

And did you see his photo of the Duemilanove with the blinking LED 13: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1228305758/9#9

?

Oh, that’s totally 'shopped. :smiley:

–Phil.

Oh, that’s totally 'shopped.

Two points: one, I refuse to give any money to the amoral disgusting pigpile of a corporation that is Adobe, so don’t refer to the technique using their trademark; and two, “a picture is not taken, it is made,” said photo legend Ansel Adams. :slight_smile:

The animated one is obviously a composite I took from two photographs. The oscilloscope is also done using two photographs (one with the flash and one without), to give a faithful representation of the backlit LCD. I can get a lot more complicated than that, but generally avoid complexity where possible. Other than that, I’ll share my totally simple photo techniques that will help anyone do technical shots better.

Please do tell, those pictures are truly impressive :slight_smile:

/me is all ears

Thanks!

PS I use GIMP

so don’t refer to the technique using their trademark;

You’re assuming I didn’t mean Paintshopped :-)-- no offense intended. In future I will use the phrase “Oh, that’s totally gimped.” :smiley:

The oscilloscope is also done using two photographs (one with the flash and one without), to give a faithful representation of the backlit LCD.

Cool, I didn’t realise that.

And, yes, they are impressive shots. Thanks for sharing your techniques.

–Phil.

follower, no problems…

What kind of camera, lighting, settings and software did you use?

Did you use some kind of combine filter?

Thanks :slight_smile:

Hello all,

Sorry for double posting this in NEWS also, but I might have posted in the wrong thread. I’m sorry if these are stupid questions, but I’m new to this hobby of ours, and understand nothing about scopes. I’m having trouble deciphering the listed specs to know what they may mean to me.

Basically, I’m wondering if the jyetech scope is suitable to measure a IC that outputs pulses at between 5 to 20 pulses per second (I guess that would be called a Hertz)? The pulses are between 0.1v to 3.0v. I would be interested in seeing the voltage of the output as it varies (I suppose this the amplitude?) Also the waves could vary between square waves, or sawtooth waves, with rising and/or falling edges that may be either stepped or sloped.

What I plan to do is to read the signals output from a chip I am programming against other pre-programmed chips. I need to compare their frequency levels, voltage ranges, and waveform shapes.

Does this scope have the precision necessary for me to see the characteristics I mention?

I’ve seen the specs at jyetech[dot]com/en/default.html but sadly have no idea what most of them mean:

Max sample rate - 2M/s[ch65292]8 bits

Sample memory depth - 256 bytes

Analog bandwidth - 1MHz

Vertical sensitivity - 100mV/Div - 5V/Div

Vertical position adjustable with indicator

Input impedance - 1M[ch937]

Max input voltage - 50Vpp

DC/AC coupling

Horizontal - 5[ch956]s/Div - 10m(minute)/Div

Auto, normal and single trig modes

Rising/falling edge trigger

Thanks so much for the help!

I ordered it in kit form thinking it might make a nice intro-to-smt kit. I really bit off more than I can chew. I spent about 5 minutes staring at it and decided not even to attempt it. I put it all back in the shipping bag where it’s been sitting for a couple of months. It did come with everything the assembled one does like the front and back panels.

It’s still in perfect condition exactly as it was shipped. Think I’d have any luck trying to resell it?

Edit: Also, about the picture, did you use a light tent? I’ve had pretty decent results without (using an off-camera speedlight bouncing off the background), but I do sometimes have trouble with the shadow.

just a warning:

do NOT update to the latest firmware from jyetechs website.

You will kill the bootloader, brick your scope and feel bad.

Until now there are not all files needed to recover the device anywhere to be found. The manual states one needs 2 hex files (firmware, bootloader) and the eeprom file. The last 2 are not available right now ;-(

Solution in other thread: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1223639021/55 reply post 55