ADS1015 Integrated Circuit (enlarged 20x; actual size: 2 x 1.5mm)
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The Texas Instruments ADS1015 +/-24V Analog Digital Converter is a 2 x 1.5mm integrated circuit implemented by both AdaFruit and Pimoroni as I2C-compatible breakout boards (Pimoroni's is a "Breakout Garden" board). It can be used to measure an analog voltage between -24V DC to +24V DC, returning a value with 12 bit precision.

The ADS1015 has four channels (labeled A0, A1, A2 and A3) that can read voltages from -24V to +24V at sampling rates up to 3.3KHz with a 12-bit resolution. The Pimoroni board only provides three of these channels as usable pins.

ADS1015 Breakout Boards (click to enlarge)
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The thumbnail image to the right is roughly the size of the Adafruit and Pimoroni boards, which measure 28 x 17mm and 24 x 21mm respectively.

As of January 2020 the price of the AdaFruit board is US$9 (~NZ$14), the price of the Pimoroni board is £12 (~NZ$24). The Adafruit board is also available from DigiKey NZ at NZ$16.57 (where shipping is free if you order over NZ$66).

Features#

ADS1015 Block Diagram
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  • 12-bit precision (Adafruit also sell a 16-bit version, see ADS1115Content unavailable! (broken link)https://service.robots.org.nz/wiki/images/out.png)
  • +/- 24V (DC) measurement range
  • three or four channels (the TI ADS1015 has four: AdaFruit's provides all four, whereas Pimoroni's board only provides connections to three of them)
  • programmable gain (please consult the ADS1015 TI datasheetContent unavailable! (broken link)https://service.robots.org.nz/wiki/images/out.png for details; the default is set at ±2.048V)
  • pp to 3.3KHz sampling rate
  • I2C interface (The Pimoroni board uses address 0x48 or 0x49 with a cut trace; the Adafruit board can be programmed for up to 4 different addresses)
  • 3.3V or 5V compatible
  • reverse polarity protection

Both boards arecompatible with all models of Raspberry Pi and Arduino, depending on which software libraries you intend to use.

Installation#

The Adafruit board has its own installation page (which we won't repeat here, see ReferencesContent unavailable! (broken link)https://service.robots.org.nz/wiki/images/out.png below).

For the Pimoroni board, Python and pip (or pip3 for Python 3) must be installed.

Then, if you're using Python 2, just run: 

sudo pip install ads1015
or for Python 3: 
sudo pip3 install ads1015

Example Usage#

The board has three input pins, labeled A0, A1 and A2. Plugging a signal into A0, here's an example of some code to repeatedly read the voltage on the pin until you type Ctrl-C: 

    #!/usr/bin/env python3
    import time      
    from ads1015 import ADS1015
    
    print('''read-all.py - read the A0 input of the ADC.
    
    Press Ctrl+C to exit!
    ''')
     
    CHANNEL = 'in0/ref'
    ads1015 = ADS1015()
    ads1015.set_mode('single')
    ads1015.set_programmable_gain(2.048)
    ads1015.set_sample_rate(1600)
     
    reference = ads1015.get_reference_voltage()
    print("Reference voltage: {:6.3f}v \n".format(reference))
    
    try:
        while True:
            value = ads1015.get_compensated_voltage(channel=CHANNEL, reference_voltage=reference)
            print("A0 value: {:6.3f}v".format(value))
            time.sleep(0.5)
    
    except KeyboardInterrupt:
        pass

References#

Tags:  Sensor

This particular version was published on 2020-01-19 23:49 by Murray Altheim.Top