Dear,
I am litlebit new here. I 've got a problem with my MINI PRO. I am using it for a CLOCK.
Every time I start and stop the Serial Monitor the Clock Initializes the program.
Does any body know what causes the problem?
On the UNO and most Arduino boards, the USB-Serial chip includes a DTR ("data terminal ready") line that goes low each time the USB connection is established with a host. This briefly pulls the Arduino’s reset line low through a capacitor, causing the board to reset.
You can find solutions for this issue online - Typical solutions include adding a capacitor (usually 100 nF) between the DTR pin and the Arduino reset line to ensure proper reset timing, disabling auto-reset in the Arduino IDE by cutting the reset trace or using a resistor (typically 10 µF) between reset and ground, or using an external USB-Serial adapter that allows control over the DTR line. Some boards also allow toggling the auto-reset option in software or firmware settings but not the UNO / pro mini to my knowledge.
That is how it works.
Starting the serial monitor resets the Pro mini.
Is it a problem?
I don't think it is a serious problem, but the PRO UNO is connected to a MEGA Main program.
When troubleshooting, they run not sync anymore when starting Serial at the UNO.
Rather that using the IDE serial monitor you can use a serial terminal emulator like PuTTY that does not reset the board.
No need to mess with hardware and you can still upload programs.
OK, many thanks for helping me!
I have never gotten that to work on a windows PC - Always resets no matter what software I use - even after messing around with the DTR settings.
My solution was to cut the trace and install a small switch. When the switch was closed, the board was in the default mode or “Program” mode which allowed me to upload code and it reset when I opened Serial Monitor.
With the switch open, it was in “run” mode which did not allow me to upload code, but I could open Serial Monitor (or any other program) without the board resetting. Worked well.
The version of Putty I have (0.73) doesn't have a DTR setting or RTS setting. I use it all the time and it does not reset the board.