Powering the core

Looks like VCC is accepted on pin 24. Does it accept a range of input voltage (if so, what range)? Or does the input voltage need to be cleaned up to 5v before it is fed to the spark core?

Additionally, anyone know what the “RAW” pin 1 is for?

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You can power the Core in two ways - either supply a regulated 3.3V to pin 24 (VCC), or supply an unregulated 3.7V to 6V to the VIN pin (pin 1), which will be regulated using the Core’s on-board LDO.

EDIT: The voltage regulator values changed since this post was originally created, so I have updated them to be accurate.

Hi Zach What do you think on powering the core from the mains via a capacitive type supply or is that just too risky? ie not enough current ,there are alot of modules that get power this way. cheers Dene

Pretty risky - the current draw of the Core can be 100mA to 300mA when the Wi-Fi module is activated, which is way too much for a capacitive power supply (I believe they’re intended for applications where total power consumption is in the range of ~10mA or less).

For something like this, better to power it with a switch-mode power supply. Luckily, since we’ve got a micro USB port on board, that means you can use any little USB power supply, like the kind you’d get from Apple or Samsung for your smartphone.

Hi Zach,
So am I correct in saying that you can power the core and a custom shield using a USB power supply ? Assuming the shield only needs power for some components and not a beer fridge :slight_smile:

That is correct :smile: The Core is designed to limit power drawn from the USB port to 500mA (including what’s passed on to the pins). But if you do figure out how to power a beer fridge from the Core, let me know, kay?


Hey Zach,

Figured I should bump this and hopefully you get a notification. This thread comes up as the first link in a google search for “spark core input voltage.”

Unfortunately it seems this is old info since I plugged 12v into one of my new cores on the raw port and it promptly smoked it. Needless to say I was mildly upset about that so I started looking around to see what I did wrong, the datasheet currently says the Max Voltage Input is 6VDC.

Being that this post comes up as the first link in Google you may want to edit your reply so more people don’t fall into the same trap as myself (not looking at the posting date and just seeing CEO and just going with it).


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Thank you @jboswell, and sorry for the confusion. Yes, this is an old post, which relates to Spark Core v0.1; since then we switched to a different voltage regulator, and now the voltage is limited to 6V.

Are you handy with a soldering iron, or even better, a hot air rework gun? If so, I can help you fix your Spark Core by replacing the voltage regulator.

Hi Zach, what is the range of acceptable voltages for pin 24? Would 3 x AA NiMH cells be suitable? When the cells are fresh, this would be around 3.8~4.0V. I realise this would be enough to power the core through the LDO on pin 1, but as the cells discharge, this might soon drop below the 3.7V needed for the LDO, limiting useful battery life. Hence my question about connecting the cells to pin 24.

If not, my other option would be 4 cells connected to pin 1.

Joe, have you tried powering the core with 3.3V regulated on pin 24? If it comes back to life, that would prove its just the LDO that got smoked.

The CC3000 can handle up to 3.6V, so I wouldn’t recommend any more than that - but if you’re feeling adventurous, keep us posted :slight_smile:

@PaulRB I have a few little 3.3v regulators around, I will breadboard one up and see if the core comes back and I only smoked the regulator (it sounds like that is all I did).

@Zach, I am somewhat handy with a soldering iron (don’t have a hot air gun though, I should get one at some point). Do you have a PN for that regulator or a link that I can order it from?



@jboswell the P/N for the voltage regulator that we use is:

Microchip Technology, P/N: MCP1825S-3302E/DB

I looked through SparkFun, but didn’t find a pin-compatible equivalent. There may be one there or on Seeed Studio or Adafruit’s site that I didn’t notice immediately. If all else fails, the link for that exact P/N on DigiKey is


Hope that helps!

Just ordered 10 from Digikey, many thank yous!


Hey guys can I use The LiPo charger to power spark cores?

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@sarang I just took a quick look across the datasheet, but it looks like it boosts the 3.7 Li-Po to 5.2V with 500mA+, which are both within the necessary specifications for providing power to the USB connector or Vin pins of the Core.

If you end up purchasing one, let us know how it works! As the Li-Po battery starts to drain, either the supplied amperage or voltage may start to drop, which might affect the Core’s ability to send Wi-Fi bursts and connect to the Cloud. This shouldn’t happen during regular operation, though, based on the specifications of the charger.

Would you anticipate any problems powering these from 12V (from a power supply for some LED systems) using a MCP1702 or MCP1703A running at 5V? The output current seems a bit too low if running at 3.3V to VCC, but by going with 5V on VIN, it seems like enough power?


The are probably outputting insufficient current (250mA)…

12v to 5c is a rather big jump and even an LDO regulator is not going to be power efficient.

Maybe a buck converter is more appropriate in terms of efficiency.

The relay shield uses a buck regulator IC so you can take reference from there. :wink: