C++ for bioloid

[ryann2k1]

Does anyone develop programming language for the bioloid with c++?hopefully you can help me since the robot only comes with c programming.
Thank you.

cheers

ryann2k1

[roycepipkins]

I once back-ported the WinARM make file to WinAVR. At the time WinAVR didn't do auto-dependences either, but the WinARM make file did C, C++ and auto-dependences all together.

You might want to take a peek at WinARM to see how they do it. When I get back I try to round up what I have or just redo it.

[limor]

the ATmega provides small amount of memory and in order to implement fancy C++ classes, inheritance, polymorphisms etc. the compiler usually needs lots of memory to do stuff behind the scenes.

So don't expect your ATMega embedded code to look pretty. advanced programmers (coders) always look at the output assembly code in order to do manual optimizations. The high level language provides a good startup point.

There are C++'ish compilers for Atmel.
Check out http://www.avrfreaks.net/index.php?modu ... =viewTools

[savuporo]

the ATmega provides small amount of memory and in order to implement fancy C++ classes, inheritance, polymorphisms etc. the compiler usually needs lots of memory to do stuff behind the scenes.

C++ is used in lots of embedded projects with plenty of success, but you have to be careful of the pitfalls.
Im a embedded developer myself, although i mainly work in 32-bit ARM space, and we mostly use C++ with occassional assembly. We usually have more wiggle room than Atmega.

To avoid bloat, avoid certain language features like RTTI, use templates only very carefully ( good guide is to typedef all the template instances and use only the typedefed types ) and thoroughly think through whether you want exceptions or not. Exceptions add roughly 20% code space and thus increase runtime memory footprint, if you can live without them, great. But this makes error checking everywhere more of a pain, and you cant use certain useful libraries.
Use heap sparingly if at all, and if you do, write or use nondefault allocators tuned for small systems ( dlmalloc is a good implementation, very customizeable )


Look at Stroustrup page here, search for "embedded". especially interesting reading material is the Joint Strike Fighter coding standards document. It contains lots of good guidelines, with reasoning behind the choices. The analysis is there, you can pick your own conclusions.

In short, C++ is suitable for embedded, and depending on skills of programmer, can actually beat C implementations in size requirements, but definitely it can beat them in readability and maintainability.

[acy.stapp]

Does anyone develop programming language for the bioloid with c++?hopefully you can help me since the robot only comes with c programming.
Thank you.

cheers

ryann2k1

I'm using C++ with WinAVR. I had to modify the default makefile but everything works fine. Here are the lines you need to change in your makefile. You'll need to find the correct lines and patch them manually:

Code: Select all

# List C source files here. (C dependencies are automatically generated.)
SRC = Example.cpp Servo.cpp
...
# Define all object files.
OBJ = $(addsuffix .o,$(basename $(SRC))) $(ASRC:.S=.o)

# Define all listing files.
LST = $(ASRC:.S=.lst) $(addsuffix .lst,$(basename $(SRC)))
...
CFLAGS += -Wall -Wstrict-prototypes
CFLAGS += -Wa,-adhlns=$(addsuffix .lst,$(basename $(<)))
CFLAGS += $(patsubst %,-I%,$(EXTRAINCDIRS))
...
# Compile: create object files from CPP source files.
%.o : %.cpp
   @echo
   @echo $(MSG_COMPILING) $<
   $(CC) -c $(ALL_CFLAGS) $< -o $@

# Compile: create object files from CPP source files.
%.o : %.c
   @echo
   @echo $(MSG_COMPILING) $<
   $(CC) -c $(ALL_CFLAGS) $< -o $@

# Compile: create assembler files from CPP source files.
%.s : %.cpp
   $(CC) -S $(ALL_CFLAGS) $< -o $@

# Compile: create assembler files from CPP source files.
%.s : %.c
   $(CC) -S $(ALL_CFLAGS) $< -o $@
...
clean_list :
   ...
   $(REMOVE) $(OBJ)
   $(REMOVE) $(LST)
   $(REMOVE) $(addsuffix .s,$(basename $(SRC)))
   $(REMOVE) $(addsuffix .d,$(basename $(SRC)))
   $(REMOVE) .dep/*




[ryann2k1]

Thx acy.stapp it's really helpful.

Cheers,

ryann2k1

[limor]

acy.stapp , if you have some neat c++ classes you wish to share related to the bioloid and cm5, will be of much appreciated.

[acy.stapp]

Later tonight I'll set up a sourceforge project for my stuff. Right now I've just got two classes built: Servo and Fixed.

class Fixed is a simple templatized math class that allows you to use fixed point numbers with standard math notation. This is much faster than floating point and has the same precision throughout its range which makes certain numerical solutions more stable. You can choose the number of fraction bits, the base storage type, and the storage type for intermediates. A Fixed<3> is a signed, two's complement fixed point number with 1 sign bit, 12 integral bits, and 3 bits of fraction. This lets us store and calculate with a servo position or velocity with 2 bits on top and 3 bits below.

Servo is an interface class to the AX-12+ and the sensor module. It handles reading and writing registers, pinging the servos, caching the device status, and has some nifty features like only writing changed values to the servo eeprom (since there is a write limit for those registers) and waiting the 5ms after writing an eeprom register. Functions are present to let you read fixed point speed, load, and position values, converting reads from the sign-bit representation of the AX-12 to a faster-calculating fixed-point representation. Fixed point values can also be written back to the AX-12+. Packets are constructed directly into the usart FIFO for efficiency. The generated code is very good.

The code is still in a hobbyist state while I write it. The communications stuff will be factored out next, it's still using the example communications setup.

[ryann2k1]

Hi acy.stapp,

I have tried to use your makefile source code but there is an error warning.

# Compile: create object files from CPP source files.
%.o : %.cpp
@echo
@echo $(MSG_COMPILING) $<
$(CC) -c $(ALL_CFLAGS) $< -o $@

The warning comes from @echo line.
How did you overcome this?
Thank you.

Cheers

ryann2k1

[limor]

Later tonight I'll set up a sourceforge project for my stuff. Right now I've just got two classes built: Servo and Fixed.

There's a project called "robosavvy" on sourceforge which will consolidate lots of the source code and 3D graphic files that show up here on the forum.

http://robosavvy.svn.sourceforge.net/vi ... vvy/trunk/

if you would like to use this project to upload your code, please let me know your sourceforge user name and i'll add you to the project.

[acy.stapp]

Hi acy.stapp,

I have tried to use your makefile source code but there is an error warning.

# Compile: create object files from CPP source files.
%.o : %.cpp
@echo
@echo $(MSG_COMPILING) $<
$(CC) -c $(ALL_CFLAGS) $< -o $@

The warning comes from @echo line.
How did you overcome this?
Thank you.

Cheers

ryann2k1

Try out my makefile from
http://robosavvy.com/Builders/acy.stapp/

[ryann2k1]

Hi,acy.stapp
After I compiled, the warning pops out about this line below

cc1plus.exe: warning: command line option "-Wstrict-prototypes" is valid for C/ObjC but not for C++

and how do you implement timer128.c?

make.exe: *** No rule to make target `../../AVRLib/timer128.o', needed by `AngieGynoid.elf'. Stop.

Another error also

Gynoid.cpp: In function `int main()':
Gynoid.cpp:749: error: invalid conversion from `const char*' to `byte*'
Gynoid.cpp:749: error: initializing argument 1 of `void TxDString(byte*)'

looking forward to your respond.
Thank you.

cheers,

ryann2k1

[acy.stapp]

Hi,acy.stapp
After I compiled, the warning pops out about this line below

cc1plus.exe: warning: command line option "-Wstrict-prototypes" is valid for C/ObjC but not for C++

and how do you implement timer128.c?

make.exe: *** No rule to make target `../../AVRLib/timer128.o', needed by `AngieGynoid.elf'. Stop.

Another error also

Gynoid.cpp: In function `int main()':
Gynoid.cpp:749: error: invalid conversion from `const char*' to `byte*'
Gynoid.cpp:749: error: initializing argument 1 of `void TxDString(byte*)'

looking forward to your respond.
Thank you.

cheers,

ryann2k1

The '-Wstrict-prototypes' error can be ignored or you can just find that line are remove it from the makefile. It is a C-only option but I haven't modfied the makefile yet to have different C and C++ options.

timer128.c is from the Procyon AVRLib (google it). I'll be migrating a lot of my stuff over to this later. Remove the file from your SRC= line.

TxDString needs to be changed to void TxDString(char const *) or TxDString(char const *) (same thing). You'll have to add some casts to bytes inside TxDString or rework the lower-level functions to take const parameters.

[ryann2k1]

Hi acy.stapp,
It seems all the library from the company (dynamixel.h) need to be reworked.
Once I try to fix TxDstring, than all errors pop up... writebyte, writeword, all functions need to be fixed.
Which dynamixel library do you use?
I thought it was easy , just add several lines in the makefile...
any idea?
Thank you...

cheers,

ryann2k1

[siempre.aprendiendo]

This simple and dirty c++ example works for me with the WinAVR

http://robosavvy.com/Builders/siempre.a ... o/cpp0.zip