INAV Temperature Sensor Configuration

I. Feature Overview

INAV now supports connecting temperature sensors via I²C bus (LM75) and 1-Wire bus (DS18B20). Temperature data can be displayed on OSD and used for logging.

Feature	Description
Supported chips	LM75 (I²C), DS18B20 (1-Wire)
Display methods	OSD display + logging
Number supported	Up to 8 temperature sensors
Default support	F4/F7 flight controllers are supported by default, F3 requires custom firmware compilation

II. LM75 Temperature Sensor Wiring Instructions

• Package: SOP-8 (common module: CJMCU-75)
• Communication interface: I²C (up to 400kHz)
• Supply voltage: 2.7V ~ 5.5V
• Measurement range: -55 ~ 125°C
  On the purple LM75 (CJMCU-75), the address pin on the bottom of the PCB needs to be bridged to GND or VCC to define the I2C address
  
  Address Settings
  The CJMCU-75 module has three address configuration pads (A2, A1, A0) on the back that can be connected to VCC or GND to set a unique I²C address:
  | A2 | A1 | A0 | I²C Address | INAV CLI Address |
  | --- | --- | --- | --- | --- |
  | GND | GND | GND | 0x48 | 0 |
  | GND | GND | VCC | 0x49 | 1 |
  | GND | VCC | GND | 0x4A | 2 |
  | GND | VCC | VCC | 0x4B | 3 |
  | VCC | GND | GND | 0x4C | 4 |
  | VCC | GND | VCC | 0x4D | 5 |
  | VCC | VCC | GND | 0x4E | 6 |
  | VCC | VCC | VCC | 0x4F | 7 |

Important

Note: Each LM75 device address must be unique.

III. DS18B20 Wiring Instructions

• Package: TO-92 / SO-8 / µSOP-8
• Interface: 1-Wire (requires DS2482 intermediary chip)
• Power supply: 3.0V ~ 5.5V (parasite power not supported)
• Range: -55 ~ 125°C
  Wiring Method:

1. Use DS2482 as I²C to 1-Wire converter;
2. Connect DS2482 to flight controller I²C bus (SCL/SDA);
3. Connect all DS18B20 DQ pins in parallel, with a 4.7k pull-up resistor between them and VCC;
4. Connect receiver DQ pin to DS2482 DQ.

IV. CLI Configuration for Temperature Sensors

4.1 Command Format

temp_sensor
temp_sensor reset
temp_sensor <index> <type> <address> <alarm_min> <alarm_max> <osd_symbol> <label>

4.2 Parameter Description

Parameter	Description
index	Sensor configuration number (0~7)
type	1 for LM75, 2 for DS18B20
address	LM75: 0~7; DS18B20: 64-bit ROM hexadecimal address
alarm_min	OSD blinks when temperature is below this value (unit: 0.1°C)
alarm_max	OSD blinks when temperature is above this value (unit: 0.1°C)
osd_symbol	OSD icon ID (0 means use label)
label	Text label with up to 4 characters (e.g., ESC, BATT)

4.3 OSD Icon ID Reference Table

ID	Meaning
1	General temperature icon
2	ESC temperature
3	VTX temperature
4	Motor temperature
5	Battery temperature
6	External ambient temperature

V. CLI Configuration Examples

• Set sensor 0 to use ESC temperature icon:

temp_sensor 0 1 0 -200 600 2

• Set sensor 3 (DS18B20) to use label BATT, minimum alarm 0.5°C, maximum alarm 45°C:

temp_sensor 3 2 7d01186838f2ff28 5 450 0 BATT

VI. OSD Display Label Alignment Method

The temperature label alignment on OSD can be set through parameter osd_temp_label_align:

Value	Display Method
LEFT	Left alignment: T1 xxx°C
RIGHT	Right alignment: T1 xxx°C

VII. Additional Information

• Use the temp_sensor command to view all configured sensors;
• Use temp_sensor reset to clear all settings;
• DS18B20 address needs to be obtained through detection method, it is recommended to connect first and then run temp_sensor to view automatic recognition output.
  ————This article is referenced from the INAV official website: https://github.com/iNavFlight/inav/blob/master/docs/Temperature%20sensors.md