Hi,
I am starting work on a project that would require a processor to interact with a custom chip that we have designed and also with a robotic arm. The processor will be programmed to control the robotic arm based on the inputs from the custom chip. The inputs from the custom chip would be required to undergo certain DSP operations and then run some control algos. This will all have to be real-time. I looked at the offerings by ARM and would want to pick one of Cortex-R processors (R4, R5 or R7). I am not sure if something.as powerful as Cortex-A would be needed for this.
Can anyone share their experiences using Cortex series of processors for any similar application that involved real-time DSP so that I can use it as a guiding metric? I would be very grateful.
Thanks
Gaurav
Hi Guarav- Welcome to the community. You might be interested in this project being done by some students in Guatemala Bionic RoboHand Prototype - Myoelectric controller based on DSP and Machine Learning julioefajardo
Thanks, bradnemire, for alerting us of this. A Cortex-M4 might be a good choice for you. It has a DSP CMSIS library available for free from the ARM website that will ease some of the DSP algos programming. I will tag pbeckmann to answer this in a more technical manner.
Dear Gaurav,
I second Brad's recommendation of using an ARM Cortex-M4 as exemplified in the link he provided. Assuming you are a student at a university/college, here's how ARM University Program can help you quickly and effectively get your hands on an ARM Cortex-M4 Kit. You may want to tell your Faculty project coordinator/guide about ARM University Program's Flagship DSP Lab-in-a-Box (LiB) around the ARM Cortex-M4 based STM32F4-Discovery Kit. The DSP LiB as you will see comes with a slew of Teaching Materials made By and For academics - Lecture Slides with Notes for a semester-long course on DSP, Exercises per topic with Solutions, Lab Experiments per topic with Solutions, Projects with Solutions and, lastly, sample mid-term and final Exams with Solutions. Since you are looking for help on your project, the lab experiments and/or projects parts of the DSP LiB would definitely be of value to you. The detailed lecture slides would also provide you with a wealth of information on how to get going on that particular ARM Cortex-M4 based STM32F4-Dscovery Kit. So you may request your faculty coordinator/guide to in turn send us an online donation request for this DSP LiB or drop us a line at university@arm.com.
Would like to add that the Cortex-M processors are also very much designed for real-time applications and have been used as such. The Cortex-R processors are really for those real-time applications additionally requiring exceptionally high performance, reliability and safety. Hope this helps.
Regards,
Sadanand Gulwadi
ARM University Program Manager, Bangalore
I second Sadanand's response. Control applications typically use a relatively low sample rate (a few kHz) and the M4 has plenty of processing power for this. The Cortex-R and the Cortex-A (and even the recently announced M7) have much more power than you would need.
Another thing to consider is interrupt latency. For control systems its important to keep the input to output latency as low as possible. The M4 interrupt handler has a 12 cycle latency which is phenomenally low. If you use a Cortex-A processor you'll probably use Linux and the latency from the operating system is going to make it unusable. The M4 is a better choice and is easier to program and develop with.
How about ARM11 Samsung 6410 based OK6410-B virtual machine?
Details refer to http://www.forlinx.net/?p=27&a=view&r=50
Hope the suggestion is helpful.
Rgds,
Grace
grace@forlinx.com