Arduino Pro Micro

Hi there, firstly I have to put it out there I’m very new to diy electronics in general, have never used Arduino before & have no coding skills. That said I have made my own IR headtraker & just yesterday I made my first button box with one of the ‘generic usb joystick pcb’ & I have a small soldering iron & can manage to solder. Anyway the question I have is will these Pro micro Arduino’s come preloaded with the BOOTloader or BOOTstrap (I can’t remember the name right now sorry) As I said above I can not code & so I want to use MMJoy2 to program the Arduino but I am unsure of the extra process involved with unofficial Arduino “based” boards that use the ATmega32U4 ‘chip’ but don’t have the BOOTloader installed. I’m sorry if I’m not making sense this is all very new to me. Any help with this would be great. The main goal for me is to make button boxes that make use of not just momentary & latching buttons but also rotary encoders with push function, switches & potentiomiters. So to sum it up, Do these Arduino Pro Micro ATmega32U4 boards come ready to be used with MMJoy2? &/or is there a product that will do what I’m wanting without the need for coding or MMJoy2?

It would be very unlikely that you would find any ‘Arduino compatible’ boards that aren’t supplied with the bootloader installed. Perhaps what you are thinking of is that the Pro Mini does not come with a USB interface, and needs a separate USB-to-Serial converter in order to connect it to a PC USB port, to interface with the Arduino IDE. So it does have the bootloader, but if you want to program it from a PC using the IDE then you need to have the converter. This is usually called a FTDI breakout or just FTDI cable, after the chip that is usually used. Once you connect the FTDI device between the Pro Mini and the PC USB port, it works almost like any other Arduino board: the only significant difference is that you might have to do a hardware reset after each program download.

FTDI devices can be purchased as complete cable sets or as bare boards. Some are 5v, some 3.3v, and some selectable as either.


This yotube video here at around that time point & the ‘extra’ steps taken shown after is what concerns me, if I don’t need to do that part I feel alot more confident about buying Arduino & being able to use the MMJoy software to program it. Thank you for taking the time to reply & giving me help it’s much appreciated.

The instruction at the top to skip this step if your Arduino board has been equipped with bootstrap loader applies to you - the Sparkfun Pro Micro is equipped with a boot loader so you should skip the step. If it is the Pro Micro you are using and not the Pro Mini then you don’t even have to worry about the FTDI breakout. Just plug it in, select the board (Arduino Pro or Pro Mini) and the port, and you are good to go.

But note that there is no apparent reason for that video to go into the details of installing a bootloader - it is something that the vast majority of Arduino users will never do. The fact that he goes into such detail about how to do a task that should never be necessary makes me wonder if there is something else in the process that could erase or damage your bootloader and require a re-installation, but from a quick survey I can’t see anything like that . Perhaps he is just being extremely thorough.

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