I am in the beginning of my forray into circuit design and I started out designing circuits around microcontrollers. I am not sure, but I seem to detect an anti mictrocontroller sentiment in the breeze around here. Is it just me, or is that case? If so, why? The feeling I get is that the general collective unspoken opinion is that using a microcontroller is akin to "cheating" or "taking the easy way out". Am I on the right track?

 

I am surprised to hear you say that. As a general rule, microcontrollers are often suggested as the solution of choice for many project assistance requests provided the member seeking assistance is willing to invest in the time to learn the basics and sufficient project funds to purchase the tools.

hgmjr

 

I have a sentiment against microcontrollers. They just seem to be used too much, for simple things, and the result is there is no way to avoid a high priced replacement part.

For instance, a defrost timer for a refrigerator used to be a mechanical timer that I could buy for $35. Now that a microprocessor chip can be had for about $1 in OEM quantities, the defrost timer board costs $85. Go figure! It's barely more than a 555 timer function and the spst temperature sensor switch is external to the board.

I designed a circuit board with discrete components to replace a microcontroller board for an air conditioner/electric furnace, and saw immediately why the microcontroller was better than discretes for that job...if you don't count using an old fashioned "stacked sequencer", a fan relay, and a 3 minute restart delay module (if the thermostat doesn't already contain a restart delay). Hmmm. If the microprocessor in my central air ever dies, I can replace it with 2 relays and a $13 timer module. I can't do that for my customers because my insurance doesn't cover redesigning the controls.

Another one I found on this site, the heater fan motor in a Ford used to use 2 resistors and a sp4t switch for speed control. Now it uses a microcontroller with a dozen or more functions in it. Guess what that costs compared to 2 resistors?

Microprocessors have their place, but don't go nuts with them, please.

 

People use the tools they know. In hobby and educational projects I see overuse of μControllers by people who know no other way. Code kids are often on the forums asking for hardware advice. The opposite side of that is the older guys always trying to do everything with discrete components as if IC's hadn't been invented and in the middle ground we have the TTL cookbook types who think every circuit can be built with logic gates.

In industry, there seem to be two reasons to use μControllers; first, to prevent reverse engineering of a design and second, to prevent field repair and increase sales of PCB modules.

 

I don't have a sentiment against µC, I just don't use them. I will get around to it eventually.

There is one thing that that bothers me though. The learning curve for someone who is totally new is as sharp as any I can come up with, and not everyone is into coding. I have some experience with coding, I've written in 6502 and Z80 assembly. I keep seeing people who love microcontrollers trying to explain how easy it is, it isn't. It is is cheaper, once (and this is not a given) you have the right equipment. Coding is hard work too.

Quite a bit can be done with simple electronics, with no CPUs involved. But you need some background with electronics when dealing with a microcontroller. They are not the best first choice when dealing with a beginner in electronics, and the things you can learn about older stuff can't help but teach new tricks for a person who is used to using PICs and whatnot.

 

People use the tools they know. In hobby and educational projects I see overuse of μControllers by people who know no other way. Code kids are often on the forums asking for hardware advice. The opposite side of that is the older guys always trying to do everything with discrete components as if IC's hadn't been invented and in the middle ground we have the TTL cookbook types who think every circuit can be built with logic gates.

In industry, there seem to be two reasons to use μControllers; first, to prevent reverse engineering of a design and second, to prevent field repair and increase sales of PCB modules.

Like all stereotypes, there are some truths, but their are even more untruths there. I am a fan of cookbooks, I'm trying to help create them for new users. They teach, which is the point. They also encourage new uses for old ideas. Most basic concepts in electronics can be looked at two or three different ways, and each way of looking at it allows you to do something different.

A lot of the older guys around here are retired engineers, and can out design anyone. This includes new and innovative uses for both old and new chips. I place that comment pretty far off base overall.

A person who can't use old tech effectively probably usually can't handle the new stuff either. With understanding comes proficiency, and proficiency comes from understanding a wide discipline of subjects.

Micro Controllers will allow for mass production by limited workshops. Overall the chips are very cheap and reusable, and like everything they have their uses, especially in the hobbiest market. They aren't for everyone though, especially most beginners. They are an excellent resource if you are one of the people who like coding (not everyone does).

The reason I hang around this site is I like learning as well as teaching.

 

I should have said that people use the tools they know and as a matter of pride, vociferously defend their use against all contradictory facts.

 

I know how to use a hammer, and every problem I encounter gets bonked on the head until it works or I get tired of hammering.



Something along those lines? (still waiting for the coffee pot to finish dripping. Maybe if I hammer on it, the coffee will perc faster!)

 

I know how to use a hammer, and every problem I encounter gets bonked on the head until it works or I get tired of hammering.

I went to use the welder last week and there were only two left hand gloves.

but I seem to detect an anti mictrocontroller sentiment in the breeze around here.

where's here?

 

KJ6 hit it on the nose. "to prevent field repair and increase sales of PCB modules". That's what bites my butt. Screwing the customers by making it impossible to repair things and gouging them for the parts they CAN get. I detest this philosophy so much that you might say I have an emotional problem with it.

I can not recommend "customer loyalty" for brands that incorporate this philosophy, which pretty much means I can not recommend customer loyalty for anything in the present condition of the world. Depending on a brand to make good quality machines that can be repaired is like expecting to get retirement checks.

The world has changed.

 

The feeling I get is that the general collective unspoken opinion is that using a microcontroller is akin to "cheating" or "taking the easy way out".

No, the people who says this kind of stuff or have this kind of opinions about using processors, actually don't have any idea that how complex it might be to design a system using processor. Many people know how to interface stuffs to processor in a prototype manner(here your mentioned people falls in),but in real professional way their is a lots of important aspect you have to consider before designing the interface hardware and even your code should be much efficient than a prototype code.

Always remember today almost whatever complex gadget you see they will have some kind of processor in them, and those professionals who built them they are using processor rather discrete.

Am I on the right track?

No, because if you are beginning with circuit designing then you have to know the basic first, processor are nothing more than a complex form of some basic circuits.
But if you know the basic then you are on the right track, and it’s the way today and future, for circuit designing.

Good Luck

 

I think the phrase 'there's more than one way to skin a cat' can be used to describe the use of microcontrollers - or not - in many simple electronic projects.

Clearly, there are some projects -even some relatively simple ones - that cry out for a microcontroller. Using analogue and/or logic gate solutions would simply be too cumbersome.

In other cases, the 'real world' interfacing (analogue inputs and outputs) can often be the dominant part of the project, and the 'control' part can often be achieved with simple logic gates, without the need for any 'code' writing at all.

It has surprised me that simple logic ICs, in several family versions and packages, are still readily available, and still as cheap as they ever were.
You might have expected the growth in microcontroller use - especially with the growing importance of cheap 'PIC' type devices - to have made a great many of the logic devices more difficult to find cheaply.
But that doesn't seem to be the case. Clearly they are still being used in quantity, by someone!

Sometimes, it can be surprising just what kind of project can be built, cost effectively, without the apparently obvious initial requirement for a microcontroller.

I recently had a requirement to relay the status of a 16 indicator parallel display - with up to 4 different illumination states for each indicator - and a max. 500mS update time - over a 500yard single pair cable.
For a peculiar set of reasons, using a microcontroller was not an option in this case.

Bit of lateral thinking, and the problem was solved, without the final cost being any more than a simple PIC pcb would have cost.

At the other end of the scale, I am sure there are lots of projects where the use of a PIC is overkill, and 3 or 4 logic gates would have done the same thing.

A lot will come down to the skills available, and in the future, this is increasingly likely to be software based skills.
For those of us who's obvious first thought is to try hardware options first --usually, as already mentioned, the 'older guys' - trying to change the mindset to start learning code late on in career is not always easy!

There are those who have the skills to use either hardware or software techniques with equal ease, and it's probably those folk who are best qualified to comment on this kind of thread.

 

Ok, well from the responses so far I think that in my mind (slightly prone to paranoia) I must have been reading into posts what wasn't there. projecting my guilty conscience onto everything. I would be one of those mentioned that would use a microcontroller even for simple things because I don't have the hardware skills to achieve the same result without one. Thanks for the input!

 

You may have noticed I like to write articles. I'm not the only one, but most of the guys who do this well have their own websites. This one is mine, I pretty much view it as such.

I've never done a search yet, but I wouldn't mind finding something similar to How I make PCBs for beginners. It would make an excellent completed projects thread. Getting started is pretty intimidating. I suspect once you have it down it is a lot easier.

 

A background in discretes is a good thing to have when using microprocessors.

That defrost timer problem I mentioned actually came down to the engineers lack of knowledge about discretes. You see, the old defrost method was to clock out 12 or 24 hours, stop the compressor, turn on a heater, wait for the spst temperature sensor to turn off the heater, and then restart the compressor. The spst sensor was designed to carry a few amps of current at 120 Vac to energize the heater. If it developed an oxide layer, the voltage would punch right through it. Using the same sensor with a microcontroller resulted in failure to register "closed" when the sensor developed 1.8k of resistance.

The designer might have allowed for any resistance up to 10k ohms or 20k ohms to register as "closed", or the designer could have specified gold plated contacts in the sensor, and the problem wouldn't have happened.

I hope this illustrates the advantage of knowing about discretes when programming a function.