0

Trinket MO power?
Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.

Trinket MO power?

by jim_lee on Mon Jun 24, 2019 5:58 pm

Started to wrap my Trinket MO into its first project. I can not find ANY info on input power limits etc. on this little thing. I have 5V and was hoping to either jam that into the BAT port or possibly the USB port. But no specs? Looked back at the old regular trinket page and it says that you can put up to 12V into the power port, but that's for the 5V version. Nothing about the 3V version.

The system is 12V-14V raw input power to run a pump, tapping off that I get 5V and i'd like to run that into the trinket MO to switch some 3V reed relays and run a sensor.

I know that hooking power into the port marked USB doesn't always work as I'd expect. Its fatal for a trinket.

-jim lee

jim_lee
 
Posts: 546
Joined: Thu May 24, 2012 8:24 pm

Re: Trinket MO power?

by franklin97355 on Mon Jun 24, 2019 8:01 pm

You can connect 5-volts to the USB pin to power the Trinket but should not have power on that pin and the USB connector at the same time.

franklin97355
 
Posts: 21088
Joined: Mon Apr 21, 2008 2:33 pm
Location: Lacomb, OR.

Re: Trinket MO power?

by jim_lee on Tue Jun 25, 2019 12:07 am

Oh, really? How about the battery power? What's the limit there?

-jim lee

jim_lee
 
Posts: 546
Joined: Thu May 24, 2012 8:24 pm

Re: Trinket MO power?

by franklin97355 on Tue Jun 25, 2019 1:19 am

From the tutorial:
Power Pins
About half of the pins on the Trinket M0 are related to power in and out: 3V, USB, BAT and GND

BAT - This is a voltage INPUT pin, you can use it to connect a battery or other external power to the Trinket. It has a Schottkey protection diode so it is completely separate from the USB power input/output. You can put 3V-6V into this pin and it will be regulated down by the 3V regulator
USB - This is a voltage OUTPUT or INPUT pin - it is connected directly to the micro USB port +5V pin, so if you are powering over usb, this pin will give you 5V out at 500mA+. Or if you are using the Trinket as a USB host or you have a good reason, you can put 5V into this pin and it will back-power the USB port.
3V - This is the 3.3V OUTPUT pad from the voltage regulator. It can provide up to 500mA at a steady 3.3V. Good for sensors or small LEDs or other 3V devices.
GND is the common ground pin, used for logic and power. It is connected to the USB ground and the power regulator, etc. This is the pin you'll want to use for any and all ground connections

franklin97355
 
Posts: 21088
Joined: Mon Apr 21, 2008 2:33 pm
Location: Lacomb, OR.

Re: Trinket MO power?

by jim_lee on Tue Jun 25, 2019 11:49 pm

Oh, that was exactly what I was looking for. I kept looking for specs. Never thought about "Tutorial". But now that I look.. Where is this Tutorial you got the info from?

Another question..

How do I set up a pin as an analog input on this machine? (I'm using Arduino c++)

-jim lee

jim_lee
 
Posts: 546
Joined: Thu May 24, 2012 8:24 pm

Re: Trinket MO power?

by franklin97355 on Wed Jun 26, 2019 12:51 am

Sorry I meant to link that in the previous post. https://learn.adafruit.com/adafruit-trinket-m0-circuitpython-arduino/pinouts
As to how to read an analog pin only analog pins can be used. https://www.arduino.cc/reference/en/language/functions/analog-io/analogread/

franklin97355
 
Posts: 21088
Joined: Mon Apr 21, 2008 2:33 pm
Location: Lacomb, OR.

Please be positive and constructive with your questions and comments.