Powering my project through Arduino USB plugged into computer. Notice when I fire it up the Green power light turns to brown at times. Does this mean it is under powered? Reason I ask is some controls stop responding.
It seems that all the breadboards are powered by my Arduino's 5V port because I have them daisy chained from a central breadboard. I then put a toggle switch on the power cable from the Arduino to the main breadboard. No matter which way I toggle the switch the other boards are still getting power. Why is this. Are they pulling power over the control cables connected to the pins? Is the toggle switch to weak? What should I do to stop this?
I want to be able to power the Arduino from a usb battery but be able to flip a toggle switch and fire up the components. What is going on? Whats the best way to do this?
I don't have one. Its all in my head and on the breadboards. I will get that free program I have read about on this site and start there. Was hoping, in the mean time, for some simple answers to the general questions.
Does a browning/dimming of the power light from green to brown mean under powered? or a current zap? or it working too hard?
How much voltage do the control pins send out? Enough to power parts of a project?
Pins provide 5V, but it's not voltage that you should worry about. You need to take the current into account. Pins can safely give you about 30 mA (and no more than 40 mA which is the point where they will likely burn out). There are also other limitations on groups of pins and total current, you can read those details in the datasheets of the microchip you have (Atmega328 for Uno, or Atmega1280 for Mega).
Is that enough for your components? I have no idea. You still haven't said what components you are using, nor how you have them wired.
However, the general rule is to avoid powering anything significant directly from the I/O pins.
Dimming of the power LED could indicate that your power supply is inadequate, that you have a short circuit somewhere, or something else.
Is the onboard voltage regulator hot to the touch?
I cannot fathom how a green LED could turn brown. :o
If it dims, clearly you are drawing too much current, it is as simple as that. Way too much current.
Yes, if you disconnect the 5V supply but have other lines set to HIGH, they will feed power to the other ICs through the protective diodes. A very unhealthy situation. Just don't do it. Power it all with the same supply, simple as that. Find a power supply capable of the whole load.
I have seen LEDS change colour, when I was wickedly overdriving them!
Seemed to head towards red in colour dependent on punishment.
A 1n4148 will light up red if you push too much current through it.
Could brown be a mix of green and red light of tortured LED?
As said, it's time to check those currents and connections, get out the multimeter and crayons!