I am looking at the Digi Connect ME 9210 as the heart of a device that also includes the ability to drive a DMX interface. DMX is a serial protocol running at 250 kbps. It transmits 513 byte frames repeatedly with an extended break condition at the beginning of each frame.
The serial interface on the 9210 would be used for a different purpose and would not be available for DMX.
I am trying to understand if I could use a FIM for this purpose under one of two conditions.
Somehow use the serial port profile for a FIM to transmit data at this rate.
Develop custom firmware for a FIM for this application. I am very experienced developing PIC firmware.
In addition it would be ideal to use a DMA engine to transfer data from a main memory buffer to the FIM in order to reduce the load on the 9210 ARM processor.
I have looked around on the website and I cannot find any documentation about the FIMs. Is it possible to get documentation? Is my application feasible with the 9210?
Are you using the Digi plug-and-play firmware, NET+OS, or Linux?
In NET+OS and Linux you could set up the available FIM on the Digi Connect ME 9210 as an additional UART, so you have two UARTs available (one SoC, one FIM).
I don’t have any background on the Linux platforms, but if you are interested in NET+OS, I did come across a white paper explaining FIM interfaces that may provide some insight. Take a look at the attachment.
Thanks for the response Mike. I am undecided between NET+OS and Linux although tending to Linux because of some previous experience with embedded linux platforms.
It would be great to use the FIM as a UART. I am unsure how I could a) create the break condition at the beginning of each frame (~92 uSec) followed by a ~12 uSec Mark and b) DMA data to the UART from main memory.
Is there documentation available? NDA is not a problem.
The documentation is part of the development kits.
I suggest you get in touch with Digi’s tech support team to discuss details (directly referring to this forum thread), which could include involving one of our FAEs to discuss the best design approach. I already provided an internal heads-up.