Powering an ItsyBitsy M4, RF board and servo from battery

Please tell us which board you are using.
For CircuitPython issues, ask in the Adafruit CircuitPython forum.

Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.
Locked
User avatar
chriswei
 
Posts: 13
Joined: Tue Jan 17, 2012 4:38 pm

Powering an ItsyBitsy M4, RF board and servo from battery

Post by chriswei »

Hi!

I've built a simple remote-controlled servo actuator with an ItsyBitsy M4, a Simple RF M4 Receiver and a Micro servo (all from Adafruit), and I'm trying to figure out how to power this setup from batteries.

I tried several of the "phone booster/charger" batteries that provide 5V over USB, but it seems my device doesn't draw enough consistent power/current when waiting for an RF signal to keep the booster battery "on" - the battery turns itself off after a minute.

I'm looking at powering it with 4xAA batteries and dropping the voltage to 5-ish V using a diode (I think I saw that approach in one of the Adafruit projects), but the more I read online, the more I see recommendations for voltage regulators or stabilizers (like the 78(L)05) to provide smoother and more consistent power.

Does anyone here have any suggestions or recommendations on how to power my project?

Thank you!

- Chris Weiland

User avatar
adafruit_support_bill
 
Posts: 88097
Joined: Sat Feb 07, 2009 10:11 am

Re: Powering an ItsyBitsy M4, RF board and servo from batter

Post by adafruit_support_bill »

Battery output is pretty stable as-is. Servos will add some noise, but the Itsy has its own on-board regulator.

The Itsy BAT pin can handle 3.5 to 6v, so a 3 or 4xAA alkaline pack would work fine. You could also use a 4 or 5xAA NiMH pack.
https://learn.adafruit.com/introducing- ... -2991166-2

User avatar
chriswei
 
Posts: 13
Joined: Tue Jan 17, 2012 4:38 pm

Re: Powering an ItsyBitsy M4, RF board and servo from batter

Post by chriswei »

Thank you for the advice!

I've also read that the RF board needs pretty close to 5V for range (I found that it'll accept 3.3V but the range is noticeably reduced) and that 6V might be too much for it. Is that the case?

To wire this up, I'm assuming I'd connect the 4xAAs (or NiMHs) to the BAT pin of the Itsy to power the board. Would I connect the servo and RF board directly to the 4xAAs, or can I use the USB pin on the Itsy for that to get 5V? Or some mix of that?

Thank you!

- Chris

PS - I'm teaching my 83-year-old Dad about microcontrollers with this project :)

User avatar
adafruit_support_bill
 
Posts: 88097
Joined: Sat Feb 07, 2009 10:11 am

Re: Powering an ItsyBitsy M4, RF board and servo from batter

Post by adafruit_support_bill »

Yes, you should keep power to the RF unit to 6v or less. You can either run power directly to the servo, or take power from the VHi pin. The USB pin won't have 5v on it unless you are connected to USB.

Locked
Please be positive and constructive with your questions and comments.

Return to “Itsy Bitsy Boards”