Hey Everyone, I just wanted to open a discussion about many replies we get here on the forum. Some folks sometimes give solutions that would only work in an ideal world (isolate sensor, noise and stability from USB port, calibrate internal reference, among others).
Honestly, sometimes the solutions proposed here are too theoretical and cannot really be applied to real life. In summary, a DIY electronics design should just work without "lab grade" testing equipment or super complex techniques to make it work under ideal conditions. In the end, conditions are never ideal, there will always be electrical noise (mostly if we use a power adapter to convert from AC to DC) and the circuits (and sensors) should still work in our imperfect electronic world. I myself have an oscilloscope and a couple of fancy diagnostic tools that help me understand the issues, but trying to make it ideal is just a dream.
I guess what I'm trying to say with this post is: Don't go crazy about looking for ideal conditions, that's probably not the reason why your circuit doesn't work. Noise and environmental conditions will always be there, and you can try to minimize them, but your circuit should still work under real life conditions. Check your components and make sure you have an understanding of how things work, check your connections and program. That's very likely where the problem is.
jarapablo:
Honestly, sometimes the solutions proposed here are too theoretical and cannot really be applied to real life
Some examples would help. I can't say I have noticed this problem.
There is no doubt that replies from different people can be based on different assumptions about the expertise of the person asking the question, and on different experience levels of the person writing the reply.
In my experience the ambiguity in questions (probably because the OP does not have the knowledge to express a technical question clearly) far outweighs problems with the responses.
However I would be very interested to see examples of what you have in mind - there is always room for improvement.
...R
PS... this seems more appropriate to the Website and Forum section and I am suggesting to the Moderator to move it
I would tend to agreee with Robin in that answers are based on many things but experience being amongst the most common.
Most Q. tend to get a variety of answers to cover a variety of conditions that could lead to the answer.
Have always been impressed by the skill levels shown in answers myself.
If you have a practical method to get the OP's to pose questions based on more facts than assumptions I would love to hear them.
I am not trying to challenge anyone's knowledge because I think most of the people who reply here are very knowledgeable. But I just think many many times we get advice that is too technical or makes everything more complex than it really is. General examples are the ones that blame the arduino/USB power for all the problems and even some that say the ground needs to be isolated. That is too much for the DIY purpose of the Arduino.
But anyway, this is one of my latest experiences with an issue I was having and the topic got sidetracked mentioning Thermal Radiation and another whole explanation of how I should completely isolate the sensors, not trust my thermostat as a reference point and take measurements for a long period of time.
I am not saying those positions are not valid, I am just saying that I don't think that this makes the Arduino way more complex and not all the times provides real insight for the issue someone is trying to address.
Topics can go off track on occasion but that is not the same as getting answers.
I just read the thread you linked to and see how it was possible for it to progress to where it did.
Your original question seemed to be looking for a high degree of repeatability and the answers followed that lead.
Personally I would have told you along the samer lines to gather them together and take readings against a known reference.
Then I would have said simply apply an offset to each to bring them into tolerance.
That vargaries of Arduino mean its possible to get differences and should anyone want supreme accuracy there is lab equiment costing magnitudes more than an Arduino that will still need to be calibrated yearly.
jarapablo:
But anyway, this is one of my latest experiences with an issue I was having and the topic got sidetracked mentioning Thermal Radiation and another whole explanation of how I should completely isolate the sensors, not trust my thermostat as a reference point and take measurements for a long period of time.
Having read through that Thread I must confess that I don't see anything to criticise. People are free to ignore advice that they don't like or don't think is relevant.
It seems to me you are looking for Forum perfection
The bigger problem I see on the Forum is people ignoring good advice that they don't understand instead of asking for an explanation.
ballscrewbob:
Personally I would have told you along the samer lines to gather them together and take readings against a known reference.
Then I would have said simply apply an offset to each to bring them into tolerance.
That vargaries of Arduino mean its possible to get differences and should anyone want supreme accuracy there is lab equiment costing magnitudes more than an Arduino that will still need to be calibrated yearly.
This makes total sense. A slightly different approach without the theoretical drama that is not doable in real life
