CJMCU-75 LM75 I2C Digital Temperature Sensor Module
CJMCU-75 LM75 I2C Temperature Sensor Module (±2°C Accuracy)
The CJMCU-75 is a compact breakout board for the LM75 digital temperature sensor, communicating over I2C. It provides accurate temperature readings with ±2°C accuracy, ideal for environmental monitoring, HVAC systems, and automation projects. The module operates from 2.8V to 5.5V and includes pull-up resistors, making it easy to connect directly to 3.3V or 5V microcontrollers.
Key Specifications
| Specification | Value |
|---|---|
| Sensor Chip | LM75 |
| Interface | I2C (up to 400 kHz) |
| Temperature Range | -25°C to +100°C |
| Accuracy | ±2°C (max) |
| Resolution | 0.125°C (11-bit) |
| Supply Voltage | 2.8V – 5.5V |
What You Can Build With This
- Build a digital room thermometer with an OLED display and Arduino Uno.
- Create a Wi-Fi enabled temperature logger using ESP32 that uploads data to the cloud.
- Design a smart fan controller that adjusts speed based on ambient temperature.
- Develop an over-temperature alarm system with a buzzer and LED indicator for machinery.
Compatibility
This module works with any microcontroller supporting I2C, including Arduino (Uno, Nano, Mega), ESP32, ESP8266, Raspberry Pi, and STM32. The onboard pull-up resistors allow direct connection to 3.3V or 5V logic levels. The default I2C address is 0x48, but you can chain up to 8 modules by configuring the A0-A2 pins.
Wiring Notes
Connect VCC to 3.3V/5V, GND to GND, SDA to A4 (Arduino Uno) or GPIO21 (ESP32), SCL to A5 (Arduino Uno) or GPIO22 (ESP32). No external pull-up resistors are needed as they are included on the module.
Why Buy from Compoden
Every component is sourced from verified suppliers and tested for compatibility before listing. We've spent 10 years building projects for makers, schools, and institutions across India. Ships from Bengaluru in 3-5 days. If defective on arrival, replace within 7 days.
Is this compatible with Raspberry Pi?
Yes, the CJMCU-75 works with Raspberry Pi via I2C. Enable the I2C interface in raspi-config, and you can read temperature using Python's smbus library.
Can I use multiple sensors on the same I2C bus?
Yes, by connecting the A0, A1, and A2 pins to different logic levels, you can set up to 8 unique addresses (0x48 to 0x4F). The module defaults to all grounded (0x48).
What is the measurement update rate?
The sensor updates temperature data roughly every 100 milliseconds, providing a balance between speed and power consumption.
📦 Free Setup Handoff Document Included
Every Compoden order includes a free setup handoff document — step-by-step instructions to get your component working within minutes. Download it via QR code on your package. The handoff document is also trained to help you troubleshoot the majority of problems.
Ask Soldr above what you can build with this — it knows every Compoden kit this part appears in.
Shipping Information
- Prepaid Orders: ₹75 for orders up to ₹999, FREE shipping above ₹999
- COD Orders: ₹125 shipping + ₹50 COD fee = ₹175 total
- Delivery Timeline: Dispatch in 1-2 days, delivery in 2-7 days depending on location
Returns & Warranty
- 7-Day Return: Manufacturing defects only (approval required)
- Warranty: 7 days from delivery
- Non-Returnable: Batteries, consumables, cut wires, clearance items