#Arduino mega 2560 uart pins serial
#Arduino mega 2560 uart pins software
#Arduino mega 2560 uart pins code

Software, hardware or simply my stupidity - whatever. But after removing the Mega's USB cable and starting both back up, the Uno to Mega to Uno communications fail.

#Arduino mega 2560 uart pins serial

Only the USB cable is attached to the Uno, e.g., no external power supply.Īll works fine as monitored by the Uno console serial connection.

I have tried multiple Arduino power supplies of 9V 1A on the Mega and tested with / without the USB cable attached.

#Arduino mega 2560 uart pins code

The wiring seems correct as shown in the code above and similar when testing Serial3, Rx-Tx crossed. The code is a small example extracted from my running Arduino system monitoring an Aquaponics system. I have tried most combination in a test bed - one Uno, one Mega and just two jumper wires. Nick_Pyner I seriously appreciate your help. In the meantime, if it works at all, the real problem is somewhere else.

#Arduino mega 2560 uart pins software

While it can be used on a Mega, provided you stay off the (multitude of) hardware serial pins and use those pins appropriate for it, software serial is never a good idea, you have to be pretty desperate if you do so, and you definitely shouldn't tell your mother about it. There really isn't anything more to it than that. Serial3 is used by connecting the other device's Rx line to pin 14(Tx), and its Tx to pin 15(Rx), as clearly marked, and using the various commands Serial3.dadedah. A standard 9v 1A should be fine to prove the point, and one would be more inclined to suspect the USB of not delivering the goods. I really can't comment on the power supply. The only exception to this is where you aren't actually using Serial3, in which case the same applies, and you are really sending data on Serial0 and reading it on your monitor via the USB cable, which is apparently not your intention.

You probably have done enough debugging for the moment anyway, because IF your communications works when you plug in the USB cable it can only mean there is nothing fatally wrong with the software, the problem is hardware, and no amount of DBugging on Serial3 will fix it. Hardware - fixed by fiddling and procedure.Whatever the problem is, it can only fall into one of two categories: This example works great until I unplug the Mega's USB cable - then communications fail.Īnd you aren't making much sense either.

SwSerial.write( (char) swSerial.read() ) The Uno is to be an Uno WiFi that simply collects data from remote data collection devices like the mega. The intent is to run the Arduino Mega as a remote data collection device, powered by a standard '9V 1A Arduino power supply adapter 110V AC' - without a USB connection to a computer, and passing its collected system probe data to an Arduino Uno via an alternative Serial connection. I am having trouble running an alternative serial line from a Mega to an Uno using either Serial3 or SoftwareSerial without the Mega's standard serial plugged into a computer's USB port.