Tutorial: Reading a TMP102 Temperature Sensor with Binho Nova and Python

Tutorial: Reading a TMP102 Temperature Sensor with Binho Nova and Python

This tutorial walks through a complete I2C sensor read workflow using the Binho Nova and Python. We will connect to a TI TMP102 digital temperature sensor, scan the I2C bus to find it, read the temperature register, convert the raw data to degrees Celsius, and build a simple temperature logging script.

The TMP102 is a common I2C temperature sensor used in industrial monitoring, server thermal management, and battery pack temperature sensing. Its I2C interface and straightforward register map make it a good starting point for learning Binho Nova’s I2C capabilities.

What You Need

• Binho Nova multi-protocol USB adapter
• TMP102 breakout board (available from Adafruit, SparkFun, or equivalent suppliers)
• 4 jumper wires
• USB cable (included with Nova)
• Python 3.7+ installed on your computer
• Binho Python package (pip install binho)

Wiring

The TMP102 uses a standard I2C connection plus power and ground. Connect the Nova to the TMP102 breakout as follows:

Nova Pin	TMP102 Pin	Function
IO0 (SCL)	SCL	I2C clock
IO1 (SDA)	SDA	I2C data
3V3	VCC	Power (3.3 V)
GND	GND	Ground

The Nova provides a 3.3 V output on its power pin that can supply the TMP102 (which draws under 10 uA in continuous conversion mode). The I2C bus has internal pull-up resistors on most TMP102 breakout boards. If using a bare TMP102 chip, add 4.7 kOhm pull-up resistors on SDA and SCL to 3.3 V.

The TMP102’s I2C address depends on the ADD0 pin configuration:

• ADD0 to GND: address 0x48
• ADD0 to VCC: address 0x49
• ADD0 to SDA: address 0x4A
• ADD0 to SCL: address 0x4B

Most breakout boards default to 0x48 (ADD0 tied to GND).

Step 1: Install the Binho Python Package

pip install binho

This installs the Binho host adapter library, which provides Python classes for interacting with the Nova’s I2C, SPI, UART, and GPIO interfaces.

Step 2: Scan the I2C Bus

Before reading temperature data, confirm that the TMP102 is present and responding at the expected address. The following script scans all valid I2C addresses:

from binho import binhoHostAdapter

## Connect to Nova (auto-detects the first connected device)
binho = binhoHostAdapter.binhoHostAdapter()
binho.setOperationMode(0, 'I2C')
binho.setI2CFrequency(0, 400000)  # 400 kHz (Fast Mode)

print("Scanning I2C bus...")
for addr in range(0x08, 0x78):
    try:
        result = binho.readFromAddress(0, addr, 1)
        if result is not None:
            print(f"  Device found at 0x{addr:02X}")
    except:
        pass

print("Scan complete.")

If wiring is correct, you should see:

  Device found at 0x48

Step 3: Read the Temperature Register

The TMP102’s temperature register is at address 0x00. It contains a 12-bit (or 13-bit in extended mode) two’s complement value representing the temperature. The default resolution is 0.0625 degrees Celsius per LSB.

## Read 2 bytes from the temperature register (register 0x00)
## First, write the register pointer
binho.writeToAddress(0, 0x48, [0x00])

## Then read 2 bytes
temp_bytes = binho.readFromAddress(0, 0x48, 2)

## Convert to temperature
raw = (temp_bytes[0] << 4) | (temp_bytes[1] >> 4)

## Handle negative temperatures (two's complement, 12-bit)
if raw > 2047:
    raw -= 4096

temperature_c = raw * 0.0625
print(f"Temperature: {temperature_c:.2f} C")

At room temperature (approximately 25 degrees Celsius), you should see a value between 20 and 30 degrees. If you see 0.00 or an implausible value, check the wiring and verify the device address with the bus scan.

Step 4: Read the Configuration Register

The TMP102’s configuration register (0x01) controls conversion rate, alert functionality, and extended mode. Reading it confirms the sensor is in its default state:

## Read configuration register
binho.writeToAddress(0, 0x48, [0x01])
config = binho.readFromAddress(0, 0x48, 2)
print(f"Config register: 0x{config[0]:02X}{config[1]:02X}")

The default value is typically 0x60A0, indicating 4 Hz conversion rate, comparator mode, and 12-bit resolution.

Step 5: Build a Temperature Logger

Combining the above into a continuous temperature logging script:

from binho import binhoHostAdapter
import time
import csv
from datetime import datetime

binho = binhoHostAdapter.binhoHostAdapter()
binho.setOperationMode(0, 'I2C')
binho.setI2CFrequency(0, 400000)

TMP102_ADDR = 0x48

def read_temperature():
    binho.writeToAddress(0, TMP102_ADDR, [0x00])
    data = binho.readFromAddress(0, TMP102_ADDR, 2)
    raw = (data[0] << 4) | (data[1] >> 4)
    if raw > 2047:
        raw -= 4096
    return raw * 0.0625

## Log to CSV
with open('temperature_log.csv', 'w', newline='') as f:
    writer = csv.writer(f)
    writer.writerow(['timestamp', 'temperature_c'])

    print("Logging temperature. Press Ctrl+C to stop.")
    try:
        while True:
            temp = read_temperature()
            now = datetime.now().isoformat()
            writer.writerow([now, f"{temp:.2f}"])
            print(f"{now}: {temp:.2f} C")
            time.sleep(1.0)
    except KeyboardInterrupt:
        print("Logging stopped.")

binho.close()

This script reads the temperature every second and writes timestamped readings to a CSV file, useful for thermal characterization during board bring-up, environmental testing, or validating enclosure thermal design.

Next Steps

With basic I2C communication working, you can extend this approach to any I2C device: IMUs, pressure sensors, EEPROMs, PMICs, display controllers, and more. The Binho Nova’s support for I2C speeds up to 3.4 MHz covers the full range of I2C devices, from legacy 100 kHz standard mode sensors to high-speed 3.4 MHz high-bandwidth peripherals.

For teams in Bengaluru, Hyderabad, Chennai, and Pune working on multi-sensor IoT boards, the same Nova and Python approach scales to reading multiple I2C sensors in a single script, building a complete board-level diagnostic tool that exercises all I2C devices on the bus.

Why Buy from GSAS

GSAS Micro Systems is the authorized Binho engineering partner in India. We provide the Nova, Supernova, and Pulsar with INR invoicing and hands-on technical support. Our applications engineers in Bengaluru, Hyderabad, Chennai, Pune, Mumbai, and Delhi NCR help teams get started with Binho tools and develop scripted workflows for sensor validation, board bring-up, and production test. Contact us for evaluation units or a demo.