I was a little leery of these after buying several off-brand SR-04 sensors from another vendor a few years ago. I had constant trouble setting those sensors up, a google search revealed that there were known issues with the firmware in knockoff SR-04 sensors from that time period.

Anyway, I received my Elegoo sensors yesterday, took one out of the bag and hooked it to a Raspberry Pi 3. It's working exactly as it should and I was able to get it running easily. Caveats on setting these up: 1) I think they use a significant amount of current, you may want to power the SR-04 separately from the Raspberry Pi power pins 2) the echo pin of the SR-04 produces a 5V pulse, so you'll need to set up a simple voltage divider to provide a 3V input to the Raspberry Pi. 3) One more reason to use Python 3 - time.perf_counter() will improve the precision of your pulse measurements!

I think you'll be happy with these, have fun!

Easy to integrate with python on a Raspberry Pi. Seems to work well as a quick way to detect distance. Planning on using it to measure the water level in my sump pump to track changes and fill rates.

This is a very nice ultrasonic sensor for tinkering with first time roboticists. Once you are able to understand the connection and simple coding to make them work the ideas begin to flow. Lacking instructions in the box, still easy to find online and get up and running.

Good product at a fair price.

Complete project description follows but the keys for the Ultrasonic Distance Sensor: 1) it's been running in a plastic box, outside, for almost a month with no problem. The Arduino wakes us every 15 minutes and takes a measurement, transmits it, then goes back to sleep. 2) it is measuring the distance TO WATER! I even turned the swim jets in my pool on to test turbulence and it works fine.

Green Pond Bridge Boat Clearance

At "˜very low tide' the clearance under Green Pond Bridge in Cape Cod is 6'6" or less and that is too low for the boat I use. The tide charts for Falmouth, MA are theoretical and can vary as much as 18" from what is actually happening at the bridge. This system monitors the clearance and transmits the information on the internet.
All of these parts were purchased from Amazon.

Transmitter

An (Arduino) Elegoo UNO R3 board is connected to an Elegoo HC-SR04 Ultrasonic Distance Sensor. The UNO and the sensor calculate the distance from a fixed dock to the sea level, then transmit that data using a MakerFocus NRF24L01 Wireless Transceiver to the Receiver described below. The Transmitter sits on the end of a dock where there is no power, so the UNO, Transceiver and Distance Sensor are powered by the energyShield 2. This battery has special capabilities "“ it wakes everything up every 15 minutes. The system takes a couple readings of the distance to the water then transmits that data, then the battery shuts it all off. The data transmitted includes information from the battery "“ time, date, and voltage.

I have been testing this unit at home (in Dallas) and it has been operating outside, for about 20 days. Based on battery drain it looks like it will operate for about 4-5 months before it needs a recharge. When the temperature drops below zero the system still works fine but the voltage reported in the battery seems low.

All of this is housed in a plastic box printed for the purpose with a FlashForge 3d Printer Creator Pro, using eSun White ABS+ filament
Picture below.

Receiver

An (Arduino) Elegoo MEGA 2560 R3 is connected to another NRF24 Transceiver to receive the data. The MEGA does the math to convert the distance from the dock to the water, to the bridge clearance. Then the information is displayed on an Elegoo UNO R3 Touch Screen (that also works fine on the Mega).
Picture below. A small plastic frame for the Receiver was also printed on the 3d printer

Web Server

Finally, the information in the MEGA is transmitted over a serial bus to a Hiletgo ESP8266 NodeMCU ESP-12E Internet WIFI Development Board (Also operates using Arduino IDE programming). This board is connected to the MEGA via the XCSOURCE Logic Level Converter and powered by a UCEC MB102 Breadboard Power Supply Module. All mounted on an Elegoo Breadboard. The ESP8266 is programmed to be a web server. It connects to the internet through the modem/router provided by AT&T.

Picture of my cell phone below.