[Bug] sdkconfig.detector default config uses HELTEC_V3 for V4 board - causes incorrect VBAT reading (reports 0 V)

[popshark1]

Bug Report

Description

When flashing the Detector firmware on a Heltec WiFi LoRa 32 V4, battery voltage is always reported as 0 V (battery_v: 0), even with a healthy LiPo battery connected to the standard battery connector.

Root Cause

The default sdkconfig.detector example in the documentation ships with:

CONFIG_BATEAR_BOARD_HELTEC_V3=y
CONFIG_ESPTOOLPY_FLASHSIZE_8MB=y

Even though the inline comment reads:

Board (use HELTEC_V4 + FLASHSIZE_16MB for V4)

When the firmware is built with HELTEC_V3, the VBAT monitoring logic targets the wrong GPIO/ADC configuration for the V4 hardware (GPIO1 / ADC1_CH0 gated by GPIO37 / ADC_Ctrl). The result is a 0 V reading on every telemetry packet.

Steps to Reproduce

1. Use a Heltec WiFi LoRa 32 V4 board.
2. Copy the default sdkconfig.detector example from the docs without modifying the board selection.
3. Build and flash the Detector firmware.
4. Observe battery_v: 0 in telemetry output despite a connected and charged battery.

Expected Behavior

battery_v should reflect the actual battery voltage (e.g., 3.82), and a low-battery flag should trigger when voltage drops below 3.4 V.

Proposed Fix

Update the default sdkconfig.detector example (or add a clear V4-specific block) to use:

CONFIG_BATEAR_BOARD_HELTEC_V4=y
CONFIG_ESPTOOLPY_FLASHSIZE_16MB=y

Environment

• Board: Heltec WiFi LoRa 32 V4
• Firmware role: Detector
• Batear version: v2.2.0
• Battery: LiPo connected to standard SH1.25 battery connector
• Solar input: SH1.25 solar panel interface (V4-specific feature)

[TN666]

#55