Automotive Oscilloscopes.

[Pugglt Auld Jock]

People who have seen some of my other posts will know I'm slowly hauling myself out of the "gravity well" with regard to automotive electronic diagnostics. Haven't even reached stage 1 separation yet though!

I have both VCDS and MES and what I've discovered is that being able to graph "stuff" is really useful. To a certain extent I can do this with both these scanners but the problem is because it feeds to you through the USB port it's quite restrictive (and also you are seeing what the car's ECU thinks it's seeing which may not actually be what's going on) It's much more useful to be able to directly connect to components, typically by back probing, so you know for sure what the trace on the screen relates to.

Because of this I'm very interested in Automotive oscilloscopes and I've been looking at the options for quite a while now. I like Laptop based systems and there are some almost affordable options obtainable from the far east but, without going into detail, there are problems to overcome if you go this route, not least of which is support for an electronic dinosaur like me. I think it's important for anyone interested to realize that, although you can use a more general purpose 'scope you would be well advised to buy a dedicated automotive one or you will spend lots of time trying to understand how to set up the X and Y axis values and maybe choosing attenuators etc. The dedicated item has presets and suggestions to solve this (probably has an inbuilt library of waveforms etc to help you too). I've also discovered it would seem to be best to avoid very cheap options as they are unlikely to give the resolution or sampling rate you need.

"Everybody" - including an acquaintance who has his own garage - seems to say the Pico just can't be beat. Trouble for me is I don't have, and couldn't justify spending, that sort of money. I'm very interested in the Foxwell OS 100 4 sold by our friends at Gendan £395 is pretty good but still a lot of money. When you look closely at it it looks like a Hantek? casing looks the same anyway? and it's the Hantek which you can buy direct from the east somewhat cheaper. I do read about configuration problems with these though, which I'm sure Gendan would help with if you bought their Foxwell version.

Now to the reason for this post. About a month or so ago - I don't think I posted at the time? - I came across a you tube video of someone playing around with one I hadn't come across - it's a DITEX - Here's their site: https://autoditex.com/

I think you are looking at around £600 to get set up so a big saving over the Pico and still out of my reach just now but I like the look of it. What might be of immediate interest to some of us though is the Library they've made available. I've spent hours in there and it's fascinating. Pico do the same and between the two there's an absolute wealth of info to be gained for ignorant newbies like me.

So, dive in, why don't you, but beware 'cos it's addictive.
regards
Jock

 

[andydiver]

Cpc components, the DIY variant of Farnell, have a number of scopes including Pico. While not directly automotive I have little doubt that you could figure it out, especially as the Pico has good auto ranging and so on. However I would ask exactly what you need to be measuring, normally it is to see a pulsed output or pwm, or maybe a CAN signal, really very slow speed by scope standards, so no need for big budget. Also note that stand alone units with TFT screens and so on are so very much better than old scopes, so much easier to use, auto scaling and ranging. The trigger setup is the most important and they are all much better than old. I understand your hesitation, sure you will be fine.
There was a battery powered one around, will have a look for it, in a tidy size format. Spend on screen size above all else for car work, then every detail and adjustment gets easier to identify.

 

[PuntoHowTo]

Back in the Mid 2000's I worked for Fluke here in Norwich, At the time part of the facility was given over to making "probes" which was a fancy way of saying clamp meters, which where in many cases bespoke to the automotive industry. They where not something the public could buy as they where designed and made to meet car manufactures requirements, they where used on production lines and would be clipped on to various parts of the wiring looms to measure voltage, currents, wave forms, electrical flux density.

Realistically these things where so specialists that they would be completely useless without the specialist equipment they connected to.

In my opinion as someone who had previously worked both on cars and the technology used my manufacturers, I would argue there is not a lot on modern cars that a home DIY mechanic would need a scope for.

Even some specialist care electricians I used to know didn't get that far into things.

These days virtually everything in the car communicates from one module to another via a digital network. You can't really see what the network is doing via a scope.

If you have a problem like for example an ABS light. The OBD port will tell you what the rough error is and where it is, say front right wheel speed sensor, so you go have a look and if the sensor looks ok, you replace it, because thats really all you can do, what would be gained from hooking it up to a scope and watching the signal coming out of it, the sensors are fairly cheap, you could maybe swap it one side to another in some cases and see if the error moves to confirm your suspicion, but many of the old analogue systems that would rely on a nice sine wave you could read with a scope are long gone. Its only what a sensor is outputting you could measure, and that's assuming you know what the output is supposed to look like and its not got interference from a poor or shared earth with a different component.

If you get into spending £100s on something like a scope are you going to make equivalent savings?

You know what you're doing jock and you're fairly switched on, I'm sure you'd have no problems getting your head round an older scope which wasn't specialist to cars but would be considerably cheaper.

 

[portland_bill]

Years ago we used to use huge oscilloscopes, small screens (like a 14" TV), but of course a cathode ray tube, so a big box. These were mounted on trolleys, or sometimes a huge cabinet. None liked hitting the joints in the concrete floor though, and they were difficult to catch once falling. Eventually a rule was made, always two people attending when moving the damn thing.
It was used mostly for ignition systems, watching the low and high tension wave forms could help diagnose misfires and power differences between cylinders. With the move to electronic ignition, their use has waned.
These days, the main benefit of a scope would be to see the wave form from a sensor, as these tend to be a digital on/off signal. As Andy says, we could just replace the component.

Like jock, I have looked at these things periodically, but for the occasional use, maybe once a year or less, replacing suspected components is far cheaper. The Chinese ones are probably adequate, but of course no help if we can't get the results we need. I can't see me spending more than £50 on one, and that would definitely be a 'want' not a 'need'.

 

[andydiver]

Some sensible observations here! Though a good storage scope with a decent screen is not large or expensive any more and quite a toy!
At the other end I have one of these and it's rather tidy

https://pokitmeter.com/

Had to make up some more useful clips for the wires. The most useful thing with this is the data logger, I used it to monitor the battery voltage on the Qubo recently over a few days with and without the charger, to prove that it had died, also the solar charger on the van. Very useful.
The scope is good enough to catch transient events, like the 5 seconds starting a car, and how much the battery voltage dips for example.
Also can be clipped under a bonnet or somewhere and you can read and so on from the seat.
You would want to use a sensible size phone for most versatility, though think they have been improving the Windows version.

 

[Pugglt Auld Jock]

Thanks all three of you. Plenty for me to chew over there. D'y know what the most valuable thing is that it's made me think about? Why do I want to do this? It's because for so many years there really has been nothing I couldn't do on a car for myself and, most of the time, I could just listen to an engine and perhaps drive the car to know very quickly exactly what was wrong with it. I hate now that there are occasions when this is no longer the case especially as cars are my passion and consuming interest

In most of the garages I worked in there was a "Crypton Tuner" and then when I became a trainer we had a quite sophisticated - for it's time - "Sun Tuner". I learned a lot about high and low tension ignition systems, alternators, etc analysis with these machines and got used to looking at scope traces rather than reaching for a multimeter (analogue of course in those days - you daren't go anywhere near electronics now with an analogue meter do you? and even if you do it reacts so slowly you often won't learn very much using it! - So the oscilloscope seems to give a more detailed way of looking at components which I can't otherwise observe? The big problem of course is that I have no training on modern systems and am feeling my way as I go. Ignition systems and alternators and oh so much more, whilst having similarities, are very different "animals" these days.

So I think perhaps PB has hit the nail on the head - as he so often seems to - when he says that what I'm feeling is best described as a "want" not a "need"!

Thanks fellers
Jock

 

[Pugglt Auld Jock]

Some sensible observations here! Though a good storage scope with a decent screen is not large or expensive any more and quite a toy!
At the other end I have one of these and it's rather tidy

https://pokitmeter.com/

Had to make up some more useful clips for the wires. The most useful thing with this is the data logger, I used it to monitor the battery voltage on the Qubo recently over a few days with and without the charger, to prove that it had died, also the solar charger on the van. Very useful.
The scope is good enough to catch transient events, like the 5 seconds starting a car, and how much the battery voltage dips for example.
Also can be clipped under a bonnet or somewhere and you can read and so on from the seat.
You would want to use a sensible size phone for most versatility, though think they have been improving the Windows version.

Sorry Andy won't work for me as my neanderthal mobile only does calls and texts and has a screen, if you can call it that, approximately the size of a postage stamp! Thanks for the suggestion though, much appreciated.
Jock

 

[andydiver]

Fair enough, and unfortunately no PC support yet, just checked. Any cheap Android phone would do....

 

[Pugglt Auld Jock]

Fair enough, and unfortunately no PC support yet, just checked. Any cheap Android phone would do....

Yes Andy, My kids just can't believe I've not got a decent mobile yet, especially as I spend so much time on this Laptop and cart my camera around with me whenever I want to take photos - it's a very nice Panasonic though and it does take very nice snaps!

One of the things that's really holding me back is perceived cost. At present my pay as you go has probably had less than £50 put into it in all the years I've owned it. I only really have it for when I leave the house in case Mrs J wants to get hold of me or in the, I suppose increasingly likely, event I need to call for help when I'm out on my own - genuinely couldn't tell you when I last made a call on it, surprised they don't shut it down! A modern mobile is going to cost shed loads more to run than that isn't it?

 

[andydiver]

It is worth noting that most Android phones do not need any kind of contract or paid connection to operate as a Web browser on WiFi. Or to support the Pockitmeter. It is quite possible that one of your family have a spare in a drawer somewhere, and it will work fine even if only for that one purpose.