It's easy to use the TMP117 with Python or CircuitPython, and the Adafruit CircuitPython TMP117 module. This module allows you to easily write Python code that reads the temperature from the TMP117 sensor.
You can use this sensor with any CircuitPython microcontroller board or with a computer that has GPIO and Python thanks to Adafruit_Blinka, our CircuitPython-for-Python compatibility library.
CircuitPython Microcontroller Wiring
First wire up a TMP117 to your board exactly as shown below. Here's an example of wiring a Feather M4 to the sensor with I2C using one of the handy STEMMA QT connectors:
- Board 3V to sensor VIN (red wire)
- Board GND to sensor GND (black wire)
- Board SCL to sensor SCL (yellow wire)
- Board SDA to sensor SDA (blue wire)
You can also use the standard 0.100" pitch headers to wire it up on a breadboard:
- Board 3V to sensor VIN (red wire)
- Board GND to sensor GND (black wire)
- Board SCL to sensor SCL (yellow wire)
- Board SDA to sensor SDA (blue wire)
Python Computer Wiring
Since there's dozens of Linux computers/boards you can use, we will show wiring for Raspberry Pi. For other platforms, please visit the guide for CircuitPython on Linux to see whether your platform is supported.
Here's the Raspberry Pi wired to the sensor using I2C and a STEMMA QT connector:
- Pi 3V to sensor VCC (red wire)
- Pi GND to sensor GND (black wire)
- Pi SCL to sensor SCL (yellow wire)
- Pi SDA to sensor SDA (blue wire)
Finally here is an example of how to wire up a Raspberry Pi to the sensor using a solderless breadboard
- Pi 3V to sensor VCC (red wire)
- Pi GND to sensor GND (black wire)
- Pi SCL to sensor SCL (yellow wire)
- Pi SDA to sensor SDA (blue wire)
CircuitPython Installation of TMP117 Library
You'll need to install the Adafruit CircuitPython TMP117 library on your CircuitPython board.
First make sure you are running the latest version of Adafruit CircuitPython for your board.
Next you'll need to install the necessary libraries to use the hardware--carefully follow the steps to find and install these libraries from Adafruit's CircuitPython library bundle. Our CircuitPython starter guide has a great page on how to install the library bundle.
Before continuing make sure your board's lib folder or root filesystem has the adafruit_TMP117.mpy file and adafruit_bus_device folder copied over.
Next connect to the board's serial REPL so you are at the CircuitPython >>> prompt.
Python Installation of TMP117 Library
You'll need to install the Adafruit_Blinka library that provides the CircuitPython support in Python. This may also require enabling I2C on your platform and verifying you are running Python 3. Since each platform is a little different, and Linux changes often, please visit the CircuitPython on Linux guide to get your computer ready!
Once that's done, from your command line run the following command:
- sudo pip3 install adafruit-circuitpython-TMP117
If your default Python is version 3 you may need to run 'pip' instead. Just make sure you aren't trying to use CircuitPython on Python 2.x, it isn't supported!
Basic CircuitPython & Python Usage
To demonstrate the usage of the sensor we'll initialize it and read the temperature measurements from the board's Python REPL.
Run the following code to import the necessary modules and initialize the I2C connection with the sensor:
import time import board import adafruit_tmp117 i2c = board.I2C() tmp117 = adafruit_tmp117.TMP117(i2c)
Now you're ready to read values from the sensor using the temperature property:
- temperature - The temperature measured by the sensor, a value in degrees Celsius.
print("Temperature: %.2f degrees C" % tmp117.temperature)
# SPDX-FileCopyrightText: 2020 Bryan Siepert, written for Adafruit Industries
#
# SPDX-License-Identifier: Unlicense
import time
import board
import adafruit_tmp117
i2c = board.I2C() # uses board.SCL and board.SDA
# i2c = board.STEMMA_I2C() # For using the built-in STEMMA QT connector on a microcontroller
tmp117 = adafruit_tmp117.TMP117(i2c)
while True:
print("Temperature: %.2f degrees C" % tmp117.temperature)
time.sleep(1)
Once you've tried out the basic example, you can play with setting and checking high and low temperature alerts. Use the code above to set up a TMP117 instance in the REPL and then use the high_limit and low_limit properties to set alerts for high and low temperatures:
tmp117.high_limit = 25 tmp117.low_limit = 10
The above will set the alert temperatures to 25 and 10 degrees C respectively. You may wish to change these values to suit your needs.
Once the limits are set, we can check them using the alert_status property to read the state of the temperature limits:
alert_status = tmp117.alert_status
print("High alert:", alert_status.high_alert)
print("Low alert:", alert_status.low_alert)
# SPDX-FileCopyrightText: 2020 Bryan Siepert, written for Adafruit Industries
#
# SPDX-License-Identifier: Unlicense
import time
import board
from adafruit_tmp117 import TMP117, AlertMode
i2c = board.I2C() # uses board.SCL and board.SDA
# i2c = board.STEMMA_I2C() # For using the built-in STEMMA QT connector on a microcontroller
tmp117 = TMP117(i2c)
tmp117.high_limit = 25
tmp117.low_limit = 10
print("\nHigh limit", tmp117.high_limit)
print("Low limit", tmp117.low_limit)
# Try changing `alert_mode` to see how it modifies the behavior of the alerts.
# tmp117.alert_mode = AlertMode.WINDOW #default
# tmp117.alert_mode = AlertMode.HYSTERESIS
print("Alert mode:", AlertMode.string[tmp117.alert_mode])
print("\n\n")
while True:
print("Temperature: %.2f degrees C" % tmp117.temperature)
alert_status = tmp117.alert_status
print("High alert:", alert_status.high_alert)
print("Low alert:", alert_status.low_alert)
print("")
time.sleep(1)
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