Hi all! First time posting here. I looked for existing answers on this, but didn't find one.
I'd like to use a USB battery pack to run my CPX. Adafruit sells the PKCELL 2200 mAh pack, which looks ideal. However, their description points out that, "If using it with a low current load, say under 100mA, the pack may 'fall asleep.'" Perhaps this is because the pack is designed to be a portable charger for your iPhone or similar device, and it uses this current level to determine when the device is fully charged.
So I am wondering if the CPX consistently draws enough current to keep this pack "awake." Is it more than 100 mA? I thought it would be easy to find a spec on this, but I haven't had any luck.
Thanks for any answers or guidance.
Stevens
CPX Current Draw and USB Battery Pack
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Please be positive and constructive with your questions and comments.
- mikeysklar
- Posts: 14194
- Joined: Mon Aug 01, 2016 8:10 pm
Re: CPX Current Draw and USB Battery Pack
Your CPX will likely draw around 15mA in an idle mode, but significantly more when LEDs or the SAMD21 M0 processor are being utilized.
It might make sense to consider a JST connected LiPo battery pack (instead of using the USB port).
https://www.adafruit.com/?q=jst+lithium ... =BestMatch
Should you want to measure the load specific to your application that can easily be done with a USB current monitor.
https://www.adafruit.com/product/2690
It might make sense to consider a JST connected LiPo battery pack (instead of using the USB port).
https://www.adafruit.com/?q=jst+lithium ... =BestMatch
Should you want to measure the load specific to your application that can easily be done with a USB current monitor.
https://www.adafruit.com/product/2690
- stevensrmiller
- Posts: 6
- Joined: Wed Jul 20, 2022 10:14 am
Re: CPX Current Draw and USB Battery Pack
Thanks, that's great info! I could probably "fake" a bigger draw by just leaving some LEDs on, or even just put a 50-ohm resistor in parallel with it. Even wasting 100 mA, a 2600 mAh battery would last several hours.mikeysklar wrote:Your CPX will likely draw around 15mA in an idle mode, but significantly more when LEDs or the SAMD21 M0 processor are being utilized.
I have one, but that's why I'm looking for a USB alternative. Constantly connecting/disconnecting the USB jack feels like it puts a lot of strain on the CPX's USB connector. It's also difficult, whereas plugging/unplugging the USB-A jack at the computer end is quite easy.It might make sense to consider a JST connected LiPo battery pack (instead of using the USB port).
Great tip, thanks again.Should you want to measure the load specific to your application that can easily be done with a USB current monitor.
Please be positive and constructive with your questions and comments.