Hello im new in using raspberry pi and node-red and i am doing a smart parking project using ultrasonic sensors. How can I use node-red with an ultrasonic sensor to detect the car if the spot is taken or not and get results and publish it in a website?

If you add a switch node - you can check the values coming from the pisrf node and send them to one output if its 5cm or less and another output otherwise. You can then use change nodes, on each output, to change the message from a number to occupied or available

Welcome to the forum. Which bit don't you know how to do?

Using node-red to get sensor readings then publish it to a website

I don't know exactly what you mean by 'publish it to a website' but I suggest getting the sensor reading working first. What sensor are you using and how is it connected to the pi?

Im using Hc-sr04 sensors and its connected using gpio pins, is that right? Sorry

If you search the forum for that sensor I think there may have been some posts about them.

I've tried but no luck, I already have the python code working. I'm trying to use node red to send sensor reading to a webpage because the website im trying to make will supposed to tell if a sensor/spot is occupied or vaccant.

try the node-red-contrib-pisrf node [image] HC-SR04 Ultrasonic Sensor - rpi-srf - status not available General The node works for me (trig connected to pin10 - echo to pin 8, gnd to pin6 , vcc to pin 1) [image] There are a a few things to check Have you got a newer 3.…

its working, now how do I display an if else message if the car distance is lets say 5cm then it will send an "occupied" message then if its >5 then it will send "available" message.

Thanks cymplecy this helped a lot

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Ultrasonic sensor object detection

General

cymplecy 1 April 2020 10:58 9

try the node-red-contrib-pisrf node

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Ultrasonic sensor object detection

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