Hi,
I only noticed know that I run the SparkFun RedBoard Qwiic on 5V/3A. It seems to work well but in the spec it is written that the input voltage should be 7-15V.
Therefore, is it safe and does it do any damage to the board and to the connect qwiic components?
The 7-15 volt figure is for input power to the board via the barrel jack. The barrel jack then gets regulated down to 5 volts for the board and 3.3 volts for Qwiic devices.
If you’re powering it via USB, 5 volts from USB gets applied directly to the board and gets further regulated down to 3.3 volts for any Qwiic devices.
I powered to the board via the barrel jack with 5V/3A power supply. Therefore, is it safe and does it do any damage to the board and to the connect qwiic components?
Looks like it really depends in the Board I/O Voltage jumper and whether or not you’ve modified it to work of 3.3v only. If you have then it looks the board should be working in +3.3v. But I am guessing you haven’t which means you are operating the +5V regulator as pass-thru without regulation. This should not be “dangerous”, but you have no regulation and could have some unexpected results if you are running the board at its maximum clock, if you have a lot of noise in the power supply, or any other things that truly depend on having the input voltage to the ATMEL chip regulated.
The board will end up running at a slightly lower than normal voltage, but that won’t cause any damage. You should be OK.