Jumper Pads

On the back of your PCB, you’ll notice jumper pads that can be used to re-route pins, or short connections using a little solder. Don’t touch these unless you know what you’re doing!

JP1GPS Low-PowerDisconnects GPS from power in Sleep Mode
JP2GPS RX SwitchSwitches GPS RX pin to D3 or TX*
JP3GPS TX SwitchSwitches GPS TX pin to D4 or RX*
JP4LiPo Meter PassthroughMeasures battery with a single resistor
JP5LiPo Switch BypassActs as a permanent switch

*RX and TX refer to ESP8266 pins

Default Connections

chart here

Jumper Descriptions


This experimental feature disconnects the GPS from power when the ESP8266 enters deep-sleep.

The GPS is connected directly to the 5V line by default, and its not recommended to re-route this deep-sleep mode until tested further.

JP2 & JP3

The ESP8266 is finicky when talking to the GPS, which uses Serial.

The GPS is connected to D3 & D4 by default, which requires SoftwareSerial to communicate - but you re-route the pins to connect directly to the ESP8266 RX & TX pins which use a reliable Hardware Serial connection.

See known bugs for more info.


The Battery Meter feature uses 2 resistors to measure voltage on analog pin A0.

Since the D1 Mini has a built-in pulldown resistor on pin A0 already, the 360K ohm resistor is redundant, and can be bypassed by just shorting the connection.

It’s still included to support other boards which might not have an internal resistor.


Shorting this jumper will connect the LiPo battery directly to the ESP8266, if you don’t have a physical switch. If you’re powering via USB, you won’t need this feature.