Question 1:
Do i need a resistor between my cell array and the arduino if I'm running into the RAW pin on the pro micro. I know current limiting is good, but if the arduino is realistically not powering much of anything (1 PWM, 4 digital pins) will it pull enough that I would need a resistor so that it does not fry?
ANSWER: NO, that makes no sense. Why ? Because the 3S Lipo (2500mAh) is also probably at least 25C , meaning the allowable
DISCHARGE rate can be 25 times the CHARGE rate (which is 1 C) In other words, this battery pack can probably deliver at least
30 to 40 A for a 10 seconds burst and the contiuous current rating would be about 20A. Therefore , the battery doesn't have a problem with a lot of current. The battery's weak link is that it CANNOT be used below the voltage of 2.3V per cell (3*2.3= 6.9V)
This means that if the fully charge voltage is 8.4V for a 3S, then when the voltage gets to 7.1V, the arduino should turn on some indicator light flashing rapidly on the back of the guitar where the audience can't see it.. Just use a 3S,2P battery (3 in series x 2 in parallel )
What you need is to sense the battery voltage using a voltage divider so you can detect it when it gets low BEFORE it is so low that the arduino Vcc drops BELOW 5V affecting the accuracy of the analog input.
Question 2: Same deal with my lasers. 2 are extracted from a laser pointer with their own limiting circuit. 2 are going to be bare diodes with a current limiting resistor (my diagram doesn't show it, but there are 4 laser circuits in parallel, each with their own arduino pin), i've hilighted a resistor before the voltage regulator in the circuit. Do i need to limit current? That resistor will eat up a lot of my power if it is in there, or will this likely be fine without, as the circuit should only pull what it needs for current right?
You need to show a complete schematic of what you are proposing because your comments indicate that you are just making stuff up as you go along without actually having a sound basis (such as Ohm's Law) for doing so. I'm not trying to make you feel bad but the questions you are asking suggest that you need to consult someone before proposing a schematic.
ANSWER:
I'm not going to answer the question as stated. Post a complete schematic (WITHOUT) any additional components such as you are suggesting. Just show the laser diodes and post the datasheets or list the specs. If you have links to the vendors that would help.
What do you mean by "Step-down Mosfet" . I'm afraid that isn't going to cut it for a specification. You need to cite a specific part number and type of device. It sounds like you are implying a regulator circuit using a mosfet. Instead of re-inventing the wheel it makes for sense to specify a 3A 5V regulator power supply. The whole current limiting line of questioning should just be avoided for the moment until we see the complete proposed schematic and some specs.
Question 3: The LEDs on the WS2811 chip seem to be acting up. I'm pretty sure the code works fine, because I got it from another friend's project which does not have the same error. It seems like their default or error state is white. They will function properly for 2 or 3 seconds (irregular intervals, leading me to think it's a glitch, not a coding problem), then sporatically flash in seizure mode (for about 1 second) and sit on white for random intervals(between 1 and 30/40 seconds, then randomly work again for a few seconds). While testing, the arduino and the leds are being supplied by different power supplies (USB and the cell array respectively). Someone told me I'm putting excess electrons into the circuit by not having them share a ground. Could that be causing the error, or is it something hardware related. Once this thing is together, there will be no change in hell of servicing it, because the chips are to be glued between two pieces of wood, as the LEDs are embedded in the fretboard of the guitar.
ANSWER:
You have to find some other source of power besides the USB. It's ok to have the USB connected if you have an adequate 9V (approx) dc external power source plugged into the dc power barrel jack. The RGB testing will require this. When the "cell array" (which, BTW, the correct name for this a "3S /2500mAh LIPO " (3S stands for 3 in Series) is powering the arduino external dc barrel jack, the USB +5V is blocked because the mosfet switch on the arduino senses the voltage at the barrel jack is > 3.3V and turns off the mosfet that normally allows the USB power to the board, so NONE of the power is coming from the USB.
someone told me I'm putting excess electrons into the circuit by not having them share a ground. Could that be causing the error, or is it something hardware related
I'm not going to comment on that description about excess electrons but suffice it to say, the RGB's power source ground and
the arduino ground SHOULD BE CONNECTED TOGETHER AT ALL TIMES. Let me rephrase that , EVERYTHING CONTROLLED BY THE ARDUINO MUST HAVE A COMMON GROUND WITH THE ARDUINO GROUND. (not yelling, just emphasizing , ok)
FYI, your battery symbol is backwards . (see attached photo)
You need to post a revised complete schematic. According to your schematic, everything is already sharing a common ground so I am a little bit confused by your question about the extra electrons remark from someone. It sounds like they were trying to describe a "Ground loop" but if you didn't have a common ground it wouldn't work. Your schematic is correct as far as the grounds are concerned.
1 - base resistor for 2n2222 transistor seems a bit small. How did you calculate the value for that resistor ? (or did you just pull a number out of the air ?)
2- I can't find a datasheet for the LMS1117 3.3v regulator but you don't put there is no reason for the 1 ohm 2 W current limiting resistors in series the LMS1117 3.3V regulator input. It doesn't help anything because the regulator will just shutdown automatically if it is overloaded. Your going to have to post the datasheet for the laser diode because your infomation is conflicting with your comments. You show the laser diode as a "200mA " device and then you claim it only draws 10 mA. That doesn't make sense.
Your schematic serves the purpose but confirms what you already stated about your limited electronics experience . (the way the transistors are shown, battey symbol backwards) which suggests that you made the right choice in posting and should refrain from designing any circuits without consulting someone on the forum.
