Battery Shield

The Battery Shield powers OpenMV Cams from a 1.8-5.5 V source through a 2.1 mm DC barrel jack, making it ideal for alkaline-battery deployments. It also accepts a wide 6-36 V input with reverse-voltage protection.

Battery Shield

For full datasheet, photos, and ordering see the Battery Shield product page.

Highlights

  • 1.8-5.5 V DC barrel jack input for battery deployments

  • 6-36 V wide input with reverse-voltage and surge protection

  • 0-6 V ADC input on P6 for monitoring the DC barrel jack voltage

Tip

Use the battery life estimator to model how long an OpenMV Cam powered through this shield will run on a given battery for a given active / deep-sleep duty cycle.

Pinout

Battery Shield Pinout

Pin reference

Pin

Function

P6

0–6 V ADC input (level-shifted to 0–2.8 V on P6) for monitoring the DC barrel jack voltage

BARREL in

1.8–5.5 V input on the DC barrel jack

PWR in

6–36 V wide input on the terminal block (reverse-voltage tolerant)

RAW out

3.5 V at up to 800 mA — direct from the barrel jack

VIN out

5.6 V at up to 600 mA — regulated from the wide input via OR’ing diode

3.3V rail

Powers the shield’s on-board electronics

GND rail

Common ground

Note

The barrel-jack voltage divider feeds P6 through a 0-ohm resistor on the back of the shield. Remove the resistor to free P6 for unrelated use.

Note

A single 0-ohm resistor on the back of the shield selects whether the DC barrel jack feeds RAW out (default) or VIN out — move the resistor to the other pad pair to switch. Useful for legacy OpenMV Cams that take their power on VIN rather than RAW.

Usage

Read the DC barrel jack voltage on P6 (the shield level-shifts 0–6 V down to 0–2.8 V before driving the pin):

from machine import ADC
import time

barrel = ADC("P6")

while True:
    # 0–6 V on the input scaled to 0–2.8 V on P6
    v = barrel.read_u16() * 2.8 / 65535
    print("Barrel jack:", v * (6.0 / 2.8), "V")
    time.sleep_ms(500)