Few if any COTS Ultrasonic Rangefinders provide a “full range” image of the echo complex, only providing the range to the closest target. Moreover, most lack a true analog representation of the return echo, i.e. echo range and amplitude. The following project provides all the above, can be modified to meet the user’s exact needs, and is relatively inexpensive.
The How It Works portion of the Build Your Own Ultrasonic Rangefinder Project is now available in PDF. All you wanted and didn’t want to know about ultrasonic rangefinders can be found within. The Quick Start Guide is found at the beginning, the How It Works section is begins halfway through the PDF.
Instead of using the BOB-09816 OpAmp breakout modules, you may construct your own gain stages. The BOB-09816 (schematic) are simple non-inverting operation amplifier gain stages, with a dc bias at half Vcc.
If you are using an Amani64 instead of the Kemani,
you only need to build the analog portion of the circuit and connect
the transmit line (pin 41 on the Kemani) to an Amani Dock of choice, as
well as the receive line (Kemani pin 21).
Connect the TX_TRIGGER line to Arduino pin 4. Connect RANGE_PWM to Arduino pin 9. Connect the GND line of the breadboard to the GND connection on the Arduino. (Ppower, GND)
If you are using an Amani64 instead of the Kemani, simply seat the
Amani on the Arduino. Define your Amani TX_TRIGGER and RANGE_PWM pins
to match the Arduino signals. Amani pin 33 = Arduino pin 4, Amani pin
Connect an external DC power source to power jack J6 of your Kemani or Amani64.
Technically you may power your Kemani or Amani64 from you Arduino.
If you choose this option I highly advise that you do not rely on USB
power alone as you are driving an analog stage. The Kemani, being a 5V
core device can be powered from the 5V port of the Arduino. The Amani64
receives Arduino power via the JP2 setting.