microcontrollers for the model engineer

[shred]

Parallax has by far the best support structure for beginners to the micro world. I've got some AVR stuff as well and it can be cheaper, but it's a lot more hassle to get everything working well.

 

[cfellows]

Further to Marv's post, I think I have a good microcontroller project to learn on and will yield a decent tool when finished.

I'm thinking that an electronic dividing heard or perhaps rotary table would be a good project. I have a bunch of different stepper motors and I also have a couple of stepper driver modules that would make the micro-controller part easy.

The stepper driver accepts input to designate stepper direction, mode (half step or full step) and, of course, step. All the micro-controller would have to do is accept user input and do the math to determine how many steps between divisions, and direction.

Gonna have to give this some more thought.

Chuck

 

[rickharris]

Parallax has by far the best support structure for beginners to the micro world. I've got some AVR stuff as well and it can be cheaper, but it's a lot more hassle to get everything working well.

I may well dispute that statement - However as always in these complex areas individuals have their own preferences.

I have used Picaxe and Parallax systems and by far chose the Picaxe both from the point of view of price and ease of use as well as their support structure - But then again I am in the UK.

They Picaxe have just announced a forthcoming 18 pin multi tasking device which promises to be very flexible in use, with up to 10 out puts available.

You pay your money and take your choice.

 

[HYTECH]

Here is a good place for PIC, AVR, ARM, and 8051 (Newb freindly) http://www.mikroe.com/
There development boards are awsome and they have Pascal, Basic and C compilers that are fairly easy to use. They also have very good support and a good forum. I bought there EasyPic4 development board to learn to use Pics. They're based it the UK and there US distributor is http://www.circuit-ed.com/.

Free online book for Programing Pic in Basic. But they have many others. http://www.mikroe.com/en/books/picbasicbook/00.htm

 

[HYTECH]

Here is a pdf of "What is a Microcontroller" from Parallax. It will teach you alot about Basic Stamps.
http://www.parallax.com/Portals/0/Downloads/docs/books/edu/Wamv2_2.pdf

 

[cfellows]

Kind of stomping all over Marv's thread here, but I'll post one more... :

I found this website this morning and kind of had an "Ah Ha" moment. If you read the descriptions, there is a link to the basic code used on each of these projects. This guy really makes it look dirt simple.

http://www.inklesspress.com/picaxe_projects.htm

Chuck

 

[bdrmachine]

Here's my 10 cents worth. ESP32 and Platformio. They are around $10 US and they have multiple cores, include bluetooth, Wifi and all the usually interface protocols. PlatformIO is free and allows realtime hardware debugging. HUGE support base and besides the $10 board, all you need is a usb cable for most boards.

 

[Peter Twissell]

+1 for ESP32.

 

[bikr7549]

I've used the Stamp quite a lot and learned a lot quickly. Advantages are that PBasic is very easy to get going with as it is very straightforward to use, and as mentioned, Parallax does offer lots of sensors and things along with the software needed to run them. Disadvantages that have made me move away from it was lack of a real time clock for timing, and the way that basic deals with floating point numbers was just a pain to deal with. I moved first to the Parallax propellor but have now switched over to the Arduino. Still learning that one, but found that if you can program something already, moving over to another isn't that big a problem. The Arduino driven rotary table seen on this site is on my list to do.

One other advantage (for me, initially) was that the Parallax microcontrollers are all made in the US, not so with the other brands, hence the price difference.

 

[bikr7549]

I've used the Stamp quite a lot and learned a lot quickly. Advantages are that PBasic is very easy to get going with as it is very straightforward to use, and as mentioned, Parallax does offer lots of sensors and things along with the software needed to run them. Disadvantages that have made me move away from it was lack of a real time clock for timing, and the way that basic deals with floating point numbers was just a pain to deal with. I moved first to the Parallax propellor but have now switched over to the Arduino. Still learning that one, but found that if you can program something already, moving over to another isn't that big a problem. The Arduino driven rotary table seen on this site is on my list to do.

One other advantage (for me, initially) was that the Parallax microcontrollers are all made in the US, not so with the other brands, hence the price difference.

And there was one other thing that did not work well for me in PBasic-trig. PBasic uses what are called binary radians (BRADS) in place if degrees, or real radians. Resolution was way off for anything of importance for me with this. I don't recall the numbers, but getting any accurate angular measurement seemed to be not possible. In this instance I was using their 2 axis accelerometer. If I can find the old data I'll put it up here if anyone is interested. Still, the PBasic knowledge I obtained was very helpful to me.

 

[mattb.351]

The MOST fun I ever had (with microcontrollers) was in the mid 1990's on a PIC16C84 writing a protocol converter. It had to convert commands over RS232 to a proprietary protocol for a mining machine (and back). Programming the PIC in assembly was really fun. The 12C508 (now I think it's 12F508) was the baby in the family and something you could rig up on a piece of vero-board in an afternoon and get programming. The biggest hurdle back then was getting access to an EEPROM eraser, something that the F version wouldn't need.

 

[Toymaker]

This conversation about Micro Controllers wouldn't have been complete without at least mentioning Arduino; thanks [I]bikr7549[/I]. Like Parallax, Arduino has a family of different Micro Controllers which are quite easy to use and program. I'm using Arduino's Mega 2560 to control my Ambitious ORC Turbine.

Marv has given a wonderful intro to Micro Controllers; I will only add that equally important to selecting the right controller is selecting all the various sensors needed to tell the controller things like, steam pressure , water level, engine rpm, burner flame sensor, and servos needed to control fuel flow to the burner, any steam valves, etc.

I find it helpful to draw a block diagram listing all the inputs and outputs of the Micro Controller. I try to include at least max values I expect the sensors to see and what type of outputs the sensors have; analog, digital, voltage range, etc...whatever parameters help me decide what I need to buy to make this project work. Once I actually buy the sensor, I like to fill in the actual specs for the various sensors.

Follow this link to see the Block Diagram.