Sending multiple characters through serial monitor at once


I recently got some Arduino Pro Minis and have been putting the OpenScale on them, however I have noticed that the new Pro Mini’s I have purchased through Core, behave slightly differently. When sending multiple characters at once in the Serial Monitor, they no longer action each of the characters. In the past you could send a serious of characters (corresponding to particular commands) at a single time. But now if I do this with these new ones, it just does the first character multiple times (i.e. if you send 3 characters it will just be as if you sent the first character 3 times in a row, instead of actually seeing what the 3 characters were).
Is this some simple issue I am missing? I have the IDE Serial Monitor set to No Line Ending, (and have tried the others), but I don’t think this is the issue. Perhaps the new Pro Minis are reading the input slightly different or buffering it slightly differently?

Any advice very appreciated.

Hey, @none1.
The thing that is going to change the microcontroller’s behaviour to a given UART message is the program that is loaded onto it - Are you sure you’re using the same OpenScale program as you may have previously? It may just be a revision difference.

Assuming it’s not:
There’s a free serial terminal program called CoolTerm that I’d recommend downloading - It gives you a lot of control over how USART frames are sent and received from the computer. In it’s default opening state you are in a raw environment, every key you press is sent straight out the serial connection immediately. From the settings you can bring up a command line so you can enter a full command and only send it with the Enter key.
Of course, you can’t use this at the same time as the Arduino serial monitor, and you need to disconnect (button, not physically) if you want to re-flash your Arduino.

Let us know how you travel, and I’ll see if anything else comes to mind in the mean time.

  • Michael

Thanks for the quick reply Michael.
I have been using the exact same program on multiple device (the OpenScale unit from Sparkfun, previous Pro Minis and these new Pro Minis from Core). I have been uploading the same program on to the different devices only minutes apart and don’t change anything in between. Presumably if it is the exact same program which is loaded then this wont be causing the issue unless there is something different with the hard ware?

In terms of Serial Monitors I have been using the Arduino IDE Serial Monitor, but also Terminal on Mac. I will give Cool Term a go, but it seems like if the software is the same and I am using the same Serial Monitor program each time and sending the same commands each time, doesn’t this mean it must be in the hardware? Thats why I was thinking perhaps these new Pro Minis buffer differently or something.

Hey, as Michael mentioned, it’s more likely to be a software issue, however, you mentioned that you purchased a few of them, do they all act in the same way?