V-Out at 0V instead of 12V

Dev Kit Support
1

Hi Y’all,

We’re trying to power an Arduino from the V-out pin on the dev board but we’re getting readings of 0V instead of 12V. Same on 2 other motes. Has this ever happened before? What should we do?

@zack_j

  • The Athenian School
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2

Hey there guys.

In order to enable Vout you can use the command line to send these commands to the mote (not the Spotter). This turns it onto the value set by the resistors (default = 12V) manually.

gpio clr vbus_bf_en
gpio clr bf_pl_buck_en

Let me know if that works.

Most of the time the handling of the power pins are internal to the firmware programs we load onto the mote (such as “hello_world” or one that you make yourself). The function within these programs to control this are covered under the functions:
bristlefin.enableVbus(); bristlefin.disableVbus(); bristlefin.enable5V(); bristlefin.disable5V(); bristlefin.enableVout(); bristlefin.disableVout(); bristlefin.enable3V(); bristlefin.disable3V();

A future guide covering these commands, and the resistor placement to get the selectable voltage you want is coming soon (we promise!).

3

Thanks Zack - we’ll give that a shot. The electrical diagrams in the technical documentation are clear on resistor placement so I think we’ve got that covered. Great to know that Vout needs to be enabled via command line gpio

4

I think the resistors come with 12V as the default and you won’t need to do anything differently other then enable vbus and vout.

Z

5

since 12V is at the upper end of the recommended Vin for Arduino, we dropped it to 9V (1 Mohm R between H9 and H10). Works great! thanks

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