Hello everyone. I can't manage to get reliable SoftwareSerial (Arduino 1.0) communication to happen between two Arduino Unos if I use over a 9600 baud rate.
Has anyone managed to get a fast and reliable HARDWARE serial baud rate between two MCUs?
What do we do if we need a serial baud rate of say, 250,000 baud?
I guess I'll try again... I need to find a way to interface one arduino (master) with multiple arduino devices (slaves) via TTL serial at a decent baud rate with a low error rate. I was thinking SoftwareSerial might be a solution as you can have multiple serial outs but I'm not finding good speeds with low error. Can HardwareSerial be hacked in order to let me use a higher baud rate than 115,200? Even if not is there a solution for some sort of TTL serial switch IC where I can switch between sending commands to multiple devices over one hardware serial UART?Thanks!
Is there a reason why you can't use SPI or I2C? It would seem your need for a such a bus is justified (now, there might be distance issues)...
Am I missing something here as far as connections go?Master sends to all slaves, only selected slave (software address - "Hey, that's me!") responds...With TTL connections between parts, lines are low between data bytes so any high from a slave becomes a high out of the OR gate.(unless I have it backwards, then use a 4 input AND gate instead, and any low becomes a low of the AND gate).So the slave have to play nice or data get garbled.At 115,200, you only got 86uS to read the data from the serial port, decide what to do with, etc, before the next byte comes in.That's 138 clock cycles, not a lot of instructions to be doing stuff.You don't want to be wasting time sending out 2 address lines to be switching some kind of mux chip. That would imlpy your slaves are out of control and sending stuff willy nilly, and then you lose even more time getting ones attention to send you proper stuff.Or letting them ramble, and lose some time figuring where the state a data sequences is.
The fastest supported speed on the Arduino is 115200. ...
FWIW, and that is probably purely academic, the Atmels are communicating fine via serial at 1Mbit/s.