DIY Test Equipment: The ByEar 2000 - A Logic Probe

RE: DIY Test Equipment: The ByEar 2000 - A Logic Probe

mike_lm — Sun, 30 Jul 2017 02:01:52 GMT

Well done, Jon!

Nice project!

Miguel

RE: DIY Test Equipment: The ByEar 2000 - A Logic Probe

Workshopshed — Wed, 26 Jul 2017 09:18:30 GMT

I was going to suggest a logic probe for this project but you've beat me to it and done an excellent job too.

RE: DIY Test Equipment: The ByEar 2000 - A Logic Probe

mcb1 — Sun, 23 Jul 2017 10:22:05 GMT

I like that it doesn't have one of those microwhatyoucallit things.

They're just a fad and won't last anywhere near as long as valves.

Logic probes certainly do have a purpose, and like all test equipment used correctly can assist in diagnosing the problem.

I think you should enter it.

Mark

RE: DIY Test Equipment: The ByEar 2000 - A Logic Probe

DAB — Fri, 21 Jul 2017 19:01:28 GMT

I like it.

Simple and elegant.

Plus if you positively had to up the ante, just add a MCU of your choice and go for signal analysis of the output for digital display.

Well done.

DAB

RE: DIY Test Equipment: The ByEar 2000 - A Logic Probe

koudelad — Fri, 21 Jul 2017 13:12:29 GMT

Thanks for reminding me of TINA-TI.

I recently stumbled upon a PSoC "variant" of this idea and I think it might be useful for some people to compare. It features an LED as an display device, but obviously, as the outputs are PWMs, it can be easily adapter to a speaker / buzzer.

https://www.youtube.com/watch?v=fqc675MijTU (I was unable to embed the video into this post.)

RE: DIY Test Equipment: The ByEar 2000 - A Logic Probe

jc2048 — Fri, 21 Jul 2017 11:02:29 GMT

Just realised that the version of the circuit I originally posted didn't have the pin numbers added - I've just changed that.

A couple of practical notes:

40 ohm speakers probably aren't very easy to come by. I have an old pair of HiFi headphones that I no longer use (because one side distorted slightly and the pads were compressed and a mess). I've just tried the sounder from one side and it worked fine. The dc resistance measures 40 ohms, just like my loudspeaker (which surprised me because I thought they were more normally in the range 20-32ohms). So that's a possibility if you have a discarded pair of headphones lying around.

[View:/resized-image/__size/600x450/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-d56aa4e1-836b-41b5-b488-4b4db76f3f8a/contentimage_5F00_184872.jpg:600:450]

You won't do any harm putting in an 8 ohm loudspeaker - it will just be much quieter - so that's worth a try too if you have one.

I threw in protection stuff for the input on the circuit but you can get away with something simpler if you are just experimenting on a breadboard. I kept the 10k in series with the input and had the 1 Meg resistors to the rails (which keep it roughly centred if the probe isn't touching anything), but didn't bother with the rest. I also left out the Schottky diode in series with the supply, which is just there to protect against getting the supply connections the wrong way round.

RE: DIY Test Equipment: The ByEar 2000 - A Logic Probe

e14phil — Fri, 21 Jul 2017 09:28:45 GMT

What a great project

RE: DIY Test Equipment: The ByEar 2000 - A Logic Probe

jw0752 — Fri, 21 Jul 2017 06:14:32 GMT

Hi Jon,

I'm really starting to love this challenge as we now have at least two really neat little tools I can build. I like the idea of a logic level probe with sound as a lot of times one has to look where one is probing and can't be watching the LEDs. Once when I was a lot younger to didn't watch where I was probing but that is another story. Thanks for a nice project. By the way you really belong on this site as you are just as crazy as the rest of us.

John

RE: DIY Test Equipment: The ByEar 2000 - A Logic Probe

shabaz — Thu, 20 Jul 2017 22:55:46 GMT

Drat. Now I need to come up with a xyz-4000 : )

A friend was shopping for a hair-dryer today, and it was a model xyz 3200 or something, which initially the store assistant assumed was 3200W, when really it was around 1kW. Good old marketing ; )

Awesome project!! I'm quite speedy with EAGLE so if you want a PCB version let me know the rough shape (e.g. pen style?) you're looking for, and I could build up some CAD files to send to you fairly quickly.

I'm working on a few miscellaneous CAD designs so it could be added to the PCB if I have space at some stage too, although that may be a while away yet.

RE: DIY Test Equipment: The ByEar 2000 - A Logic Probe

balearicdynamics — Thu, 20 Jul 2017 22:03:25 GMT

Nice project.

Enrico