Functionalities for a complex CNC controller
Posted by Briztou
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Re: Functionalities for a complex CNC controller October 03, 2017 04:55AM |
... my plans are only vague at the moment - have to define/develop all the bits'n'bytes by time.
But think to use one of my 3-axis machines with encoders (0,0025mm resolution ... the other has 0,0005mm
) and to place a pan+tilt-table (4+5 axis, too with encoders) onto the bed ... the tool-head would then be a rotating axis with absolute position encoder, so no need for "homing".
The tool-selection could be an "offset" on the rotating tool-head ... the tangential moving vector could be calculated from the last to the next position while importing/generating the G-code or "on the fly" before executing to the next move ...
Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]
Call for the project "garbage-free seas" - [reprap.org]
But think to use one of my 3-axis machines with encoders (0,0025mm resolution ... the other has 0,0005mm
) and to place a pan+tilt-table (4+5 axis, too with encoders) onto the bed ... the tool-head would then be a rotating axis with absolute position encoder, so no need for "homing".The tool-selection could be an "offset" on the rotating tool-head ... the tangential moving vector could be calculated from the last to the next position while importing/generating the G-code or "on the fly" before executing to the next move ...
Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]
Call for the project "garbage-free seas" - [reprap.org]
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Re: Functionalities for a complex CNC controller October 04, 2017 05:41PM |
It is unclear if TRACER is:
hardware electronics
firmware
software
Your mention of RAMPs seems to say
this is firmware on a Mega arduino?
hardware electronics
firmware
software
Your mention of RAMPs seems to say
this is firmware on a Mega arduino?
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Re: Functionalities for a complex CNC controller October 05, 2017 10:13AM |
Quote
cozmicray
It is unclear if TRACER is:
hardware electronics
firmware
software
Your mention of RAMPs seems to say
this is firmware on a Mega arduino?
Hi cozmicray,
Thank you, I realised that I had employed the wrong word (my english aint perfect :-) )
TRACER is a firmware, with a stepper control module. You could see it as a framework (a core? ). It provides functionnalities, like the advanced control of stepper motors, that the coder may use for its purpose.
As I wanted it to be the most adaptative, I didn't code it for a special chip, or for a special board. To be more precise, when any module must use a chip-specific function, (for example , set a timer interrupt at a specific period), it calls a generic function (set_timer_period and enable_timer_interrupt, for the previous example),. So, if you want the firmware to work on a particular microcontroller, all you have to do is to implement (or have the file that implements) all generic functions, for the micro-controller. Currently, I adapted it to the Arduino Mega, and to the Teensy35.
I mentionned RAMPS, because it is the stepper driver board I'm working with, but again, the software is not made specifically for arduino (and is less and less made for Arduino Mega, as recent modules require a FPU to work ! )
For the story, I'm currently using two RAMPS for testing pusposes, but with a Teensy... The wiring was not a pleasure ;-).
I hope my answer clarified things.
Edited 1 time(s). Last edit at 10/05/2017 10:14AM by Briztou.
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Re: Functionalities for a complex CNC controller October 05, 2017 06:56PM |
... would be interesting to check the possibilities - have some of the RADDS and two WLAN+motors expansion modules (older 2 and newer 3 driver sockets) too, so highly interested in working configurations for 5- and 6-axis controllers
Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]
Call for the project "garbage-free seas" - [reprap.org]
Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]
Call for the project "garbage-free seas" - [reprap.org]
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Re: Functionalities for a complex CNC controller October 08, 2017 03:26PM |
As a software engineer myself also with embedded experience I find myself wondering: are you wishing to do all this on your own because of the typical "Oh yeah? I cancdo it better!" common to people writing code to do something that already has other readily available solutions that have been looked at and rejected, or because you don't know what already exists?
The thing is, this domain already has many viable solutions and a large number of them are totally open-source and free-to-use, and, even better, are well-tested, proven, and maintained. I won't say that it's impossible that you could do them better, but unless you have a proven track record that says otherwise, it's unwise to claim otherwise, and expect it to work out as anticipated, without it having a far higher cost than you expected. You state you're a poor student, but what I remember from my distant past is that other than a lack of money, the biggest cost as a poor student is that of time: it makes far more sense to reuse and modify something that's been tested than to reinvent the wheel, possibly badly, and take a very long time to do it.
Software development time/effort estimates are rarely ever close to how long it takes in reality, even with long experience in the problem domain by experienced engineers.
One of the most dangerous potential problems in software development is "Second System Syndrome" which is when people set out to replace an existing application saying "the old thing sucks, it's better to redo it from scratch!" because there's what's visibly documented to the outside in documentation, but what the code actually does almost never matches outside documentation perfectly, but it's the mismatches that make the code work "correctly" in spite of what the external documentation would suggest: the only correct documentation of what the application does and should do will always be the code itself (don't depend on code comments as to how, maybe they explain why something was done, but comments can also get out of date) built with the original compiler, as even changing the compiler (due to compiler changes, intended or otherwise, due to bugs or language changes) often results in unintended changes.
The spirit and goal of Reprap is to build off the work of others, and improve upon it and return that work to the community: it's usually better to learn as much as you can from the mistakes of others before you go and make your own mistakes (most of which have already been made by others) as it will help you and the tech progress faster and cheaper.
The thing is, this domain already has many viable solutions and a large number of them are totally open-source and free-to-use, and, even better, are well-tested, proven, and maintained. I won't say that it's impossible that you could do them better, but unless you have a proven track record that says otherwise, it's unwise to claim otherwise, and expect it to work out as anticipated, without it having a far higher cost than you expected. You state you're a poor student, but what I remember from my distant past is that other than a lack of money, the biggest cost as a poor student is that of time: it makes far more sense to reuse and modify something that's been tested than to reinvent the wheel, possibly badly, and take a very long time to do it.
Software development time/effort estimates are rarely ever close to how long it takes in reality, even with long experience in the problem domain by experienced engineers.
One of the most dangerous potential problems in software development is "Second System Syndrome" which is when people set out to replace an existing application saying "the old thing sucks, it's better to redo it from scratch!" because there's what's visibly documented to the outside in documentation, but what the code actually does almost never matches outside documentation perfectly, but it's the mismatches that make the code work "correctly" in spite of what the external documentation would suggest: the only correct documentation of what the application does and should do will always be the code itself (don't depend on code comments as to how, maybe they explain why something was done, but comments can also get out of date) built with the original compiler, as even changing the compiler (due to compiler changes, intended or otherwise, due to bugs or language changes) often results in unintended changes.
The spirit and goal of Reprap is to build off the work of others, and improve upon it and return that work to the community: it's usually better to learn as much as you can from the mistakes of others before you go and make your own mistakes (most of which have already been made by others
) as it will help you and the tech progress faster and cheaper.
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Re: Functionalities for a complex CNC controller October 08, 2017 04:44PM |
Hello JonathanThompson, and thank you for your long reply, that will allow me to clarify my post.
For me, this project began as a way to learn C, and to know more about tool machines. I didn't have a great knowledge of existing softwares features, (to be honest I still don't have a great one). Initially a simple 3 dimension controller, I decided to keep developing it, and add new functionalities for two reasons, the knowledge I acquired during development, and the encouraging results I obtained. I didn't lack of time, because this project is the one on which I want to invest my time. The subject passions me, so I don't mind loosing some time for it :-).
Let me be clear, my intention is (of course) not to replace actual firmwares, and I do not mean to trash-talk any existing firmware on this topic. My approach is more "Hey that would be a nice feature, let's see if I can do it, and if it can help, perfect". I started this project partly for learning, and the features I implement are responding to my particular needs. But if in adding new functionalities, I can help reprappers, who need to control complex machines, then I think my "loss" of time was worth it :-).
Also, as I said upper, I don't have a great knowledge of existing firmwares. As I didn't want to be orientated by other firmwares, I didn't look into their documentations or codes during the coding, neither for formulas, or general methods.
Anyway, this topic is also a great occasion for me to learn more about existing firmwares. If you know one that can regulate steppers and high level kinetics for any type of geometry, adapt to any number of axis, and also be "easily" (without having to spend a week;-) ) adapted to a particular chip, I still am very interested !
Thank you again,
Briztou.
Edited 2 time(s). Last edit at 10/08/2017 04:47PM by Briztou.
Quote
JonathanThompson
As a software engineer myself also with embedded experience I find myself wondering: are you wishing to do all this on your own because of the typical "Oh yeah? I cancdo it better!" common to people writing code to do something that already has other readily available solutions that have been looked at and rejected, or because you don't know what already exists?
The thing is, this domain already has many viable solutions and a large number of them are totally open-source and free-to-use, and, even better, are well-tested, proven, and maintained. I won't say that it's impossible that you could do them better, but unless you have a proven track record that says otherwise, it's unwise to claim otherwise, and expect it to work out as anticipated, without it having a far higher cost than you expected. You state you're a poor student, but what I remember from my distant past is that other than a lack of money, the biggest cost as a poor student is that of time: it makes far more sense to reuse and modify something that's been tested than to reinvent the wheel, possibly badly, and take a very long time to do it.
For me, this project began as a way to learn C, and to know more about tool machines. I didn't have a great knowledge of existing softwares features, (to be honest I still don't have a great one). Initially a simple 3 dimension controller, I decided to keep developing it, and add new functionalities for two reasons, the knowledge I acquired during development, and the encouraging results I obtained. I didn't lack of time, because this project is the one on which I want to invest my time. The subject passions me, so I don't mind loosing some time for it :-).
Quote
JonathanThompson
One of the most dangerous potential problems in software development is "Second System Syndrome" which is when people set out to replace an existing application saying "the old thing sucks, it's better to redo it from scratch!" because there's what's visibly documented to the outside in documentation, but what the code actually does almost never matches outside documentation perfectly, but it's the mismatches that make the code work "correctly" in spite of what the external documentation would suggest: the only correct documentation of what the application does and should do will always be the code itself (don't depend on code comments as to how, maybe they explain why something was done, but comments can also get out of date) built with the original compiler, as even changing the compiler (due to compiler changes, intended or otherwise, due to bugs or language changes) often results in unintended changes.
The spirit and goal of Reprap is to build off the work of others, and improve upon it and return that work to the community: it's usually better to learn as much as you can from the mistakes of others before you go and make your own mistakes (most of which have already been made by others
Let me be clear, my intention is (of course) not to replace actual firmwares, and I do not mean to trash-talk any existing firmware on this topic. My approach is more "Hey that would be a nice feature, let's see if I can do it, and if it can help, perfect". I started this project partly for learning, and the features I implement are responding to my particular needs. But if in adding new functionalities, I can help reprappers, who need to control complex machines, then I think my "loss" of time was worth it :-).
Also, as I said upper, I don't have a great knowledge of existing firmwares. As I didn't want to be orientated by other firmwares, I didn't look into their documentations or codes during the coding, neither for formulas, or general methods.
Anyway, this topic is also a great occasion for me to learn more about existing firmwares. If you know one that can regulate steppers and high level kinetics for any type of geometry, adapt to any number of axis, and also be "easily" (without having to spend a week;-) ) adapted to a particular chip, I still am very interested !
Thank you again,
Briztou.
Edited 2 time(s). Last edit at 10/08/2017 04:47PM by Briztou.
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Re: Functionalities for a complex CNC controller October 08, 2017 08:24PM |
Quote
Briztou
Hello JonathanThompson, and thank you for your long reply, that will allow me to clarify my post.
Quote
JonathanThompson
As a software engineer myself also with embedded experience I find myself wondering: are you wishing to do all this on your own because of the typical "Oh yeah? I cancdo it better!" common to people writing code to do something that already has other readily available solutions that have been looked at and rejected, or because you don't know what already exists?
The thing is, this domain already has many viable solutions and a large number of them are totally open-source and free-to-use, and, even better, are well-tested, proven, and maintained. I won't say that it's impossible that you could do them better, but unless you have a proven track record that says otherwise, it's unwise to claim otherwise, and expect it to work out as anticipated, without it having a far higher cost than you expected. You state you're a poor student, but what I remember from my distant past is that other than a lack of money, the biggest cost as a poor student is that of time: it makes far more sense to reuse and modify something that's been tested than to reinvent the wheel, possibly badly, and take a very long time to do it.
For me, this project began as a way to learn C, and to know more about tool machines. I didn't have a great knowledge of existing softwares features, (to be honest I still don't have a great one). Initially a simple 3 dimension controller, I decided to keep developing it, and add new functionalities for two reasons, the knowledge I acquired during development, and the encouraging results I obtained. I didn't lack of time, because this project is the one on which I want to invest my time. The subject passions me, so I don't mind loosing some time for it :-).
Quote
JonathanThompson
One of the most dangerous potential problems in software development is "Second System Syndrome" which is when people set out to replace an existing application saying "the old thing sucks, it's better to redo it from scratch!" because there's what's visibly documented to the outside in documentation, but what the code actually does almost never matches outside documentation perfectly, but it's the mismatches that make the code work "correctly" in spite of what the external documentation would suggest: the only correct documentation of what the application does and should do will always be the code itself (don't depend on code comments as to how, maybe they explain why something was done, but comments can also get out of date) built with the original compiler, as even changing the compiler (due to compiler changes, intended or otherwise, due to bugs or language changes) often results in unintended changes.
The spirit and goal of Reprap is to build off the work of others, and improve upon it and return that work to the community: it's usually better to learn as much as you can from the mistakes of others before you go and make your own mistakes (most of which have already been made by others
Let me be clear, my intention is (of course) not to replace actual firmwares, and I do not mean to trash-talk any existing firmware on this topic. My approach is more "Hey that would be a nice feature, let's see if I can do it, and if it can help, perfect". I started this project partly for learning, and the features I implement are responding to my particular needs. But if in adding new functionalities, I can help reprappers, who need to control complex machines, then I think my "loss" of time was worth it :-).
Also, as I said upper, I don't have a great knowledge of existing firmwares. As I didn't want to be orientated by other firmwares, I didn't look into their documentations or codes during the coding, neither for formulas, or general methods.
Anyway, this topic is also a great occasion for me to learn more about existing firmwares. If you know one that can regulate steppers and high level kinetics for any type of geometry, adapt to any number of axis, and also be "easily" (without having to spend a week;-) ) adapted to a particular chip, I still am very interested !
Thank you again,
Briztou.
Smoothieware is great firmware from all reports I've read.
I see you're in a mode that you'll almost certainly pursue this course of action regardless
I do have concerns regarding safety: C is an absolutely unsafe and unforgiving language you can implement anything in, with top performance, including potentially-fatal bugs that are hard to track down and fix, because of the fact it does not save you from yourself. Working on code that controls hardware that could potentially cause a fire or injury if you get it wrong is an unnecessarily dangerous learning ground for a language.
I don't know what your past development experience is before this, but from what you created this thread with, what is clear is you're using macros extensively, and that has a price in readability and ease-of-use as well as debugging along with it being harder to create decent abstractions to achieve your desired flexibility. I'd suggest instead you move towards a restricted subset of C++ without using exceptions, so you can have more type safety as well as eliminate using macros, combined with making it far easier to create a modular system.
In addition to that, if you aren't already, I'd suggest you look up techniques for creating state machines, and also study (again, if needed) techniques for working with static memory allocation/mangement. What others have mentioned is a truly critical factor for making something portable, even feasible at all on these limited platforms: they have very finite resource limits considering what you need to do with them, and if only for that reason alone, I'd suggest reading through other 3D printing firmware to understand how they work within the constraints for code size and RAM constraints. It's not outside of the realm of possibility and probability that you could create something that otherwise runs fine on a simulator that has enough RAM (simulators are often less limited than the thing they simulate) or you run into that odd corner case where some control sequence requires more resources than your controller has: this can result in a horrible failure mode, with the the worst-case scenario being your code doesn't even detect the failure, and blindly works with corrupted state. Properly designed and implemented, tested state machines are useful towards working with minimal resources(both in executable code size and RAM usage) and being readily tested. Watch your memory usage perfectly and build in code to do a safe failure in every possible place it could fail in such circumstances duecto lack of memory, and do that FIRST. You can always go back and fix mistakes only if your device and you aren't destroyed because they were fatal
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