Time to graduate from old 8-bit AVRs

[Razor Concepts]

I've always wanted to get into ARM (especially the Cortex M3.. drooool...) but never really found a good dev board. Some exist (Armite pro, a futurlec one, the new maple), but it just doesn't seem much different than the 8-bit AVR besides the faster processing. So you can do logs and stuff, yipee. Till I found the ST primer 2!!!



http://www.st.com/mcu/contentid-105-110-STM3210E_PRIMER.html

I don't understand why it is not popular. You get a color LCD w/touchscreen, and 20 free I/O ports.

It would be a waste to use one of the I/O to control a servo or something, but it excels in communication - what I plan to do is have the primer 2 do all the nasty calculations, and communicate to a 8-bit avr to do the dirty work. SPI/I2c/USART/CAN, has microSd card interface, and even audio record/playback. Built in lithium ion battery.

You can reprogram it from scratch but that would take forever, right now they have their own OS installed on there, and you can code in C/C++.

I thought I was going to buy the Arduino Mega for $65 but this thing for $60 seems like a hell of a lot better.

Just placed order at mouser 

[Admin]

I want to use ARMs, and have considered them in the past . . .

However, they lack in I/O compared to 8-bit mcus . . . and they lack in community and easy to use open source code too.

I refused to upgrade from PIC to AVR for two years after learning about AVR, and didn't convert over until community and source code was available.

[Half Shell]

I want to use ARMs, and have considered them in the past . . .

However, they lack in I/O compared to 8-bit mcus . . . and they lack in community and easy to use open source code too.

I refused to upgrade from PIC to AVR for two years after learning about AVR, and didn't convert over until community and source code was available.

I agree completely! While I use ARMs as higher level processors for a lot of tasks, such as higher level goal/event planning for the robot, I use expressly micro controllers for the majority of my sub systems.

Also, razor concepts, I might be getting one of these babies soon: http://beagleboard.org/ . They're in back order right now, but when they get off I might be picking it up. If you're looking for an easy introduction to ARM programming, I recommend taking a look.

[Weird Fishes]

I'd be very interested to know if either of those boards would be able to handle ROS.

Shouldn't be too hard to get some form of ultra-small linux onto one or the other, although I bet the Beagleboard would be easier.

I think that if these ARM cores can run ROS then it should be able to become the same type of standard that AVR's have. The real issue with the ARM cores is the immense variety and lack of portable code between the dev boards. If ROS can bridge the gap between all of the different dev boards into a common user base, then I think ARM's would have tremendous usability.

I really want to get one and put ROS on it. =P

[Razor Concepts]

ROS - Ruby Operating System or Robot Operating System?

[Weird Fishes]

Robot operating system.

There was a thread about it a while ago here. It was developed by stanford and is now being maintained and promoted primarily by willow garage (who are doing some cool work by the way).

[paulstreats]

However, they lack in I/O compared to 8-bit mcus . . .

This part just isnt true. most ARM's for hobbyists are on development boards or kits, the reason for the lack of i/o or other functions is down to the design of the board and not the ARM.

the ARM7 Im currently using is the analog digital aduc7024 featuring:

-Multichannel, 12-bit, 1 MSPS ADC Up to 16 ADC channels
-12-bit voltage output DACs Up to 4 DAC outputs available
-Voltage comparator
-On-chip temperature sensor (ą3°C)
-UART, 2 x I2CŪ and SPIŪ serial I/O
-Up to 40-pin GPIO port
-4x general-purpose timers
-Wake-up and watchdog timers (WDT)
-Power supply monitor
-3-phase, 16-bit PWM generator1
-Programmable logic array (PLA)
-External memory interface, up to 512 kB

Most of the usual periherals are there along with a few others like the DAC's, and upto 40 GPIO... Quite often, you find that ARM's on development boards or tools come with some external memory, this is where most of the I/O pins go to.. but if you added external memory to your 8-bit devices would you have any IO left?

 It is also worth noting that the develoment softwares like Keil come with examle codes, although these are available on free trials, they soon become feature limitd but they are useful for the code examples that you get with them. And then look into getting a free compiler.

 The only real downside is that they dont oerate on 5v meaning that you do need an 8bit micro or some other electronics to use the sensors and actuators that you already use.

There are also some ARM's being released that contain onchip FPGA's.

 Finally it is worth noting that if you interface external memory correctly along with a flash drive then you can run Ubunto Linux directly on ARM's

[Admin]

However, they lack in I/O compared to 8-bit mcus . . .

This part just isnt true. most ARM's for hobbyists are on development boards or kits, the reason for the lack of i/o or other functions is down to the design of the board and not the ARM.

the ARM7 Im currently using is the analog digital aduc7024 featuring:

It appears to only have one UART and 6 PWM pins (on quick glance). It is however the first ARM I've seen with more than 8 ADC pins. Atmel has some nice ARMs with built in USB, but they lack in ADC and a few other things.

[Razor Concepts]

After messing around with this, basically I have come to the conclusion that it is a very nice platform - but the support isnt there yet. Just not enough people working on it to make use of everything available - I2C is currently a headache, the interrupt routines are getting messed up with the accelerometer, etc etc. On a good note, the code is surprisingly familiar to the standard C code you see in AVR studio. Instead of AVR Studio a program called RIDE is used, which has a similar appearance. You will notice some similarities, like toggling ports, shifting in registers, interrupt routines, setting up timers, etc etc. The good part is that STM has released full example code for just about every feature on the ARM chip, the problem is getting that full code to work properly with the hardware on the Primer 2, along with getting it to work with the operating system.

As a robot controller, I think the primer 2 basically fails, all it can do is do advanced calculations quickly and then relay on the information to a slave microcontroller.

Also, using other peoples code is very very easy. Since everybody is on the same platform, all you do is double click the executable BAT file in their program and it gets flashed on to the primer 2. It takes seconds to get interesting apps on it. There are plenty of games, and some interesting stuff such as the accelerometer visualizer. There are two USB ports - one is for programming/debugging, the other is for the ARM to emulate a USB device, such as a mouse or keyboard. It is kind of cool to control the cursor by tilting the primer 2.

I think for $60 it is one heck of a deal with tons of features, it is like the ipod touch but user programmable. Not very useful for robotics, though.

[Admin]

If anyone tries out an ARM from Atmel with ARMlib and WinARM, let me know! I mostly care about support and user friendliness.

[TrickyNekro]

I haven't heard good words about atmel ARMs....
I don't really remember why, but it merely comes to me that they had some noise issues or internal structure(commands??? calculations???)....

They did recommend another brand but I really don't remember which....