Hi !
I am trying to build two game controllers (that would communicate with another Arduino) for a game. Each controller will have an arduino pro mini to which I will connect:
1-one MPU-6050 accelerometer
2-one microswitch
3-one nRF24L01+ (needs 3.3v)
4-one LM1117 3.3v regulator (with one 10uF capacitor before, and one 10uF after)
5-five red LEDs (with a 74HC595 shift register and five 180ohm resistors)
6-one DIP switch (to identify the controller)
7-one vibrating Mini Motor Disc
8-a 4AA battery pack
First, I think I don't need anything else (resistors/capacitors etc). Am I right ?
As you can see, I have some components that would be at 5v (item #1, #5, #7), some at 3.3v (item #3 thanks to #4), items #2 and #6 being 'free'/passive.
I would like to have a mobile game controller (hence the nRF24L01+).
I hear a lot about "regulated" vs "non regulated" power source and I would like to avoid any damages.
Therefore, I have been thinking about the 4AA battery pack that I chose at first. This is not regulated, right ? what will happen after a while, say, one hour of gaming ?
The voltage will drop? Will the arduino stop working (i.e. detect that it is less than 5v, so shut down), or will it burn ?
How to best power the controllers to give portable regulated 5v ?
Thanks a lot for your precious help ! This is my first portable project so I am really novice in all these aspects !
It is not good to connect 4 x AA cells directly to the Vcc of the Arduino. New AA cells can give almost 1.6 V so four of them will be over the 6 V maximum limit for the Arduino. Equally the end of life voltage is about 1.1 V so will be below the minimum required.
You will be better off using six AA cells and feeding them to Vin so that they are regulated by the on board regulator.
thank you both for your answer. I see, I could use 6*AA in the Vin, but then, what would happen at end of battery life ? I will be below the voltage, so will the arduino suffer from that ?
would something like that be regulated and a 'trusted' source of 5v ? http://www.amazon.fr/dp/B001HG1ZFK
hycday:
thank you both for your answer. I see, I could use 6*AA in the Vin, but then, what would happen at end of battery life ? I will be below the voltage, so will the arduino suffer from that ?
Nothing will "suffer" or be harmed when the voltage goes too low, it just stops working.
I think a very appealing battery solution is a single LiPo cell with a boost regulator. The above linked battery pack likely uses a single LiPo cell with a boost converter.
Single cell LiPo chargers cost about $2 on ebay. A boost regulator costs about the same.
If you don't want to trust cheap ebay chargers/regulators, Adafruit sells some nice modules. I believe Pololu also sells these sorts of parts.
@Zapro : Thanks for the info on the BOD-fuse ! good to know indeed !
@DuaneDegn : Thanks as well for the explanations on batteries, I went with such battery bank. I won't need any charger as it works with usb cables that I will plug on a computer.
What about boost regulator ? why do you mention it ? I'm ok with cheap stuff on ebay