I have two Arduino, A and B, each with an nRF24L01 and an ultrasonic module (RCWL-100) connected. I would like to measure the distance between the two Arduinos using ultrasonic sensors. This means that the first Arduino A sends a start command to Arduino B via the nRF24L01 module. After the start signal, the measurement between the ultrasonic modules begins.
Arduino A -> send start messument via nrf24l01 -> Arduino B
trigger high start waiting time with timeout 1500ms for echo high
trigger low if echo hight stop waiting time and calc distance = waiting time
Arduino A <- send distance via nrf24l01 <- Arduino B
I'm looking for suitable hardware for the receiver and transmitter sides. While doing my research, I came across this video: https://www.youtube.com/watch?v=o1tlhu8H6TQ, the recording “Zola Lab and Ultrasonic Arduino-to-Arduino Communication | Arduino Blog.” That looks pretty good. The faller digital car system 3.0 also measures distance using ultrasonic sensors.
Is that possible? Or does anyone have a better idea?
Please describe in detail why you want to do this. Because right now it sounds crazy. For people to help you, we need to understand why, otherwise we could waste time helping you with something that you later realise is crazy and decide to try another way.
Actually, I want to build something like the Faller Cars system and learn how it works. In this system, each car transmits an ultrasonic signal to a driving area via a 40 kHz ultrasonic capsule. Multiple satellites then detect their own distance to the
car, and the position is calculated via triangulation. The signal on the car is activated or synchronized via the nrf24l01.
The range of typical ultrasonic sensors is only a few meters, so why the radios? The radios introduce measurement latency due to the time it takes to send and receive messages.
It is possible to measure the transit time in each direction for sound between two Arduinos, each equipped with ultrasonic modules, by triggering both simultaneously and listening to only one at a time.
With this technique the transit time is affected by air movement, which can be used to measure wind speed.
The Faller car system consists of small toy cars that run on a magnetic track. Their approximate location is determined using ultrasound. Each car emits a ping on command. Information is exchanged via radio.
I've built some slightly larger cars using an Arduino Nano and a motor driver. These cars also run on magnetic strips and communicate with a base station via radio. Now I want to track their location using ultrasound. Bluetooth RSSI is too imprecise, and Ultra Wideband is too expensive.
This topic comes up relatively often in this forum, but usually the sensors are the HC-SR04. Try searching the forum for more information. I posted my experience with the technique here years ago.
You need omnidirectiinal transceivers and two or more, physically separated antennae per vehicle to measure the difference in receive time (along with vehicle speed and direction) to find distance. If the track has any curves in it, you will need multiple measurements and compare them to a mapped track. Sounds improbable.
