Just looking at the easiest way to implement a few aspects of my next arduino project (wwvb transmitter), and was wondering if the Arduino can actually send data at 1 baud on its serial lines? Code has no problem compiling with Serial.begin(1);. But before delving deeper into the project, was hoping someone could let me know if that would work, and if the actual rate would be a pretty accurate 1 bit per second (and not some weirdly divided clock that ends up being 1.2 or 0.9 bits per second or something similar)?
Although there is no check for it in the code, all settings below 16 won't work because there will be an integer overflow in the calculated numbers. An unpatched SoftwareSerial doesn't work below 300 baud, so you don't have software support on Arduino for 1 baud serial communication.
Baud rates that low are no problem to be implemented in a simple sketch, though. Even with a simple loop() and checking for the millis() value you'd get enough precision to communicate reliably at such low rates. What device are you communicating with? Humans?
Technically even sub-second baud rates are possible. I recall that during my school days we had to build an application that auto detected the baud rate of some "strange device".
remember, if you have a bit length of 1 second it will take ten++ second to send a byte as start stop bits are still needed.