Any reviews of USB oscilloscope for £59?

[tigpha]

Hi claviéristes,

I have discovered today that BitScope offers the BS05U USB Oscilloscope - Logic Analyzer with 2 Analogue and 6 Digital Channels, 20MHz, which Farnell offers for £59.00 all included. That looks like remarkably good value, as until now most good quality 'scopes I have found are about five to ten times the price.

My keyboard obsession is steering me toward making custom Model Fs, and the capacitive sensors will need a 'scope, as these will no doubt not work as expected, and will need debugging at the electric signal level.

Has anyone used one of these, or something similar, and what is your opinion of them?

[__red__]

Hi claviéristes,

I have discovered today that BitScope offers the BS05U USB Oscilloscope - Logic Analyzer with 2 Analogue and 6 Digital Channels, 20MHz, which Farnell offers for £59.00 all included. That looks like remarkably good value, as until now most good quality 'scopes I have found are about five to ten times the price.

My keyboard obsession is steering me toward making custom Model Fs, and the capacitive sensors will need a 'scope, as these will no doubt not work as expected, and will need debugging at the electric signal level.

Has anyone used one of these, or something similar, and what is your opinion of them?

Unfortunately I don't think that a 20Mhz scope would be fast enough to do what you want to do

[tigpha]

Hi __red__,

Fair point. I suppose that if the Model F capacitive sensors are in the picofarad range, then I suppose I won't see much detail of an impulse response. But do I need to have such a high level of detail?

I don't have any decent means of measuring signals at all, at the moment. The ancient multimeter is barely useful for DC stuff. I have no means of probing into time-variant stuff. For a cost of £59, even if the specs are modest, a 'scope gives me far more insight than flying utterly blind as I am at the moment.

[__red__]

This is useful: https://www.picotech.com/library/applic ... e-tutorial

Tell you what, when I get home tonight I'll reduce the bandwidth of my scope so you can see the difference.

To be clear, it's far from useless. Honestly, the level from "toy" to serious is not that far of a jump. There are some very good chinese scopes which are cost effective that may meet your needs if you can raise the budget a touch.

[tigpha]

Thanks __red__, very informative.

According to the Pico Tech site, the BitScope would really only be suitable for audio frequency measurement. The example given of the USB 1.1 data frame capture illustrated the limitations very well, needing at least 50MS/s to analyse the waveform in proper detail, to be able to view the effects of impedance mismatch etc.

I suppose that logic-level probing the BitScope might be sufficient to capture USB 1.1 data frames, but that's beside the point: I aim to measure the waveform of a signal passing through a capacitor that has values in the pico-Farad range.

Looks like I need to save up some cash. I may need to consider rental, maybe?

[__red__]

Thanks __red__, very informative.

According to the Pico Tech site, the BitScope would really only be suitable for audio frequency measurement. The example given of the USB 1.1 data frame capture illustrated the limitations very well, needing at least 50MS/s to analyse the waveform in proper detail, to be able to view the effects of impedance mismatch etc.

I suppose that logic-level probing the BitScope might be sufficient to capture USB 1.1 data frames, but that's beside the point: I aim to measure the waveform of a signal passing through a capacitor that has values in the pico-Farad range.

Looks like I need to save up some cash. I may need to consider rental, maybe?

The most popular brand of scope for hobbyists is rigol because their scopes are intentionally hackable.

[mastermachetier]

SO I was looking into this and i found this video and review here . I think you may find it useful .

https://www.youtube.com/watch?v=x19kwG-wJRI

[tigpha]

Thanks for the suggestions __red__ and mastermachetier.

I have seen the cheap kit DSO's all over eBay. Selling at roughly £15, they're so cheap it's almost beer money, but assembly might try my patience a tad. If I make a mistake, I'm not sure my 30-plus year old digital multimeter (goodness me!) will be up to the task. Farnell might have a better chance of winning my cash.

[mastermachetier]

Thanks for the suggestions __red__ and mastermachetier.

I have seen the cheap kit DSO's all over eBay. Selling at roughly £15, they're so cheap it's almost beer money, but assembly might try my patience a tad. If I make a mistake, I'm not sure my 30-plus year old digital multimeter (goodness me!) will be up to the task. Farnell might have a better chance of winning my cash.

Ya i have never done smd soldering before , but they guy on video has some pretty good tips doesn't look to crazy on this scale , if it was for like a keyboard pcb though that another story. Anyways good luck let me know what you do since I am looking into getting one as well.

[jou]

SMD soldering looked fiddly to me until I tried it. It is actually quite doable, even when I had no idea what I was doing. Just see it in action:

[tigpha]

Thanks jou, very informative. I am ignorant about how to identify the components. This is what I meant by making mistakes, not so much the soldering, which as you say looks easy enough, as long as I abstain from drinking coffee!

I have to find an identification guide for SMT capacitors and inductors, specifically. I can measure resistors if I can't understand the markings, and I have a microscope, which is handy for positioning and inspection. Capacitors and inductors, the very few that I have seen so far, don't appear to have markings, which puzzles me.

Spending £15 on a DSO kit from eBay seems increasingly appealing...