Caution I AM A NEWBIE!!! Be gentle, ever so gentle!!!
I am currently trying to create a communication protocol that will connect several microprocessor devices together. The devices do not exist yet, because I have not designed them yet. In order to keep my sanity, I would like to store all the data in the same memory location for each of the devices such as firmware number, process variables, digital inputs and digital outputs, etc.
I have several questions...1.) Is there a why to allocate a large portion of the RAM so the micro does not use it for other processes or threads?
- Currently I write some data to the first 255 bytes in RAM. When I call a specific function, the variables in the function overwrite the data in RAM. I have came up with a work-around this, use an EPROM or Flash to store the data in. At time elapses slowly, this seems like the correct approach to take considering I would need to have some of the data not to be erased when the system is powered down.2.) Is there a standard communication protocol between microprocessor devices?
- At my last job, we were trying to to develop a new one. This did not seem to go very well. So I am inclined to to try to use one that already exist. As of now, I am playing around with Modbus. Since my knowledge over the subject extends as far as my arms will reach, I figured I would ask.3.) I2C or UART?
- Since I already know how to use SPI and I like complicating my life, I would like to use to either I2C or UART. From what I seen at my last job, I2C does not seem the way to go if there was a lot of bytes being transferred. I think that it ended up being limited to about 128 bytes per transfer. This is not knowing at what speed the clock rate is set.
Any help would be cool.
Quote: what is your raison d'être?
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