Battery Monitor

12V Lead-Acid · Arduino Uno · Pin A0 · 10-sample avg

Updated --:--:--
Tick #0
Voltage Range Indicator
Low 12.1VHigh 12.8VNow: 12.728V
11.5VCRITICAL · SAFE · CHARGING13.5V
Live VoltageNOMINAL
12.728Volts DC
RELAY OFF
11.5V12.5V13.5V

R1

30 kΩ

R2

10 kΩ

Ratio

÷ 4.0×

Relay D8
OFF — LOAD DISCONNECTED
○ DE-ENERGIZED

Trigger ≤

12.100 V

Release ≥

12.800 V

Now: 12.728 V · 0.628V above trigger

DFPlayer Mini
AVAILABLE

Voice alerts active · 5s cooldown

ADC Raw Value
651/ 1023

Pin A0 · 10-bit · 63.6% range

Calibration Offset
+23mV

Applied after ADC conversion

Voice CooldownREADY
0s remaining5s total

DFPlayer fires once per 5s window · Suppressed events logged

Sample Rate
10samples/cycle

1 cycle/sec · averaged ADC reads

Relay Threshold
12.1 / 12.8V

ON ≤12.1V · OFF ≥12.8V (hysteresis)

Voltage Trend

Last 60 seconds · 1s resolution · 10-sample average

12.1V relay-on12.8V relay-off

Voice Event Log

DFPlayer Mini · 5s cooldown · 5 events

D1 TX → DFPlayer RX
TimeEventVoltageFired
08:04:55.001CHARGING_DETECTED13.120 VFIRED
08:04:18.772BATTERY_HIGH12.830 VFIRED
08:03:49.448BATTERY_LOW12.060 VSUPPRESSED
08:03:44.211BATTERY_LOW12.080 VFIRED
08:02:11.043SYSTEM_READY12.510 VFIRED

Relay Switch History

Pin D8 · 5 transitions this session

Hysteresis 0.7V
TimestampStateTrigger VDuration
08:05:01.340OFF12.810 V9.2s
08:04:52.100ON12.070 Vactive
08:04:18.780OFF12.830 V34.6s
08:03:44.215ON12.080 Vactive
08:02:11.050OFF12.510 Vactive