Questions tagged [sensor]

For questions dealing with devices that measure the physical world around us and translate it into signals for the Raspberry Pi.

105 questions with no upvoted or accepted answers
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6
votes
2answers
4k views

Why does the Sense Hat / Astro Pi show the wrong temperature and humidity?

I recently bought the sense-hat, previously called astro-pi. Unfortunately the temperature shows 28 to 31 degrees Celsius from both temperature sensors on the board. They often show around 30 degrees ...
4
votes
2answers
268 views

Finding /dev Mount Point for Sensor

I am trying to connect to an Airmar 200WX and not having much luck finding the /dev mount point of the sensor. I have the sensor plugged in on boot and dmesg displays the following: [ 1.150836] ...
4
votes
2answers
288 views

MMA845X accelerometer mapped at 1C

I have a MMA845X accelerometer mapped at 1C: 0 1 2 3 4 5 6 7 8 9 a b c d e f 00: -- -- -- -- -- -- -- -- -- -- -- -- -- 10: -- -- -- -- -- -- -- -- -- -- -- -- 1c -- -- -...
3
votes
2answers
1k views

HC-SR505 Mini Infrared PIR Motion Sensor

I have a raspberry pi zero and a HC-SR505 (not 501, which apparently is what I should have bought). I'm a programmer, with only a little electronics from long ago, but some people suggest the it will ...
3
votes
0answers
818 views

Not getting a response from a connected PIR sensor

I have a PIR sensor which I'm using connected to a Raspberry Pi 3 Model B as part of a Magic Mirror project. I'm running this module for the sensor. I've had the Motion Sensor working before, but now ...
3
votes
1answer
2k views

Smoke detection using raspberry pi?

I was interested in making a smoke detection unit which starts taking a video and also sends an SMS once the detector detects smoke; the problem is, which smoke detector should I use? Also, how do I ...
2
votes
0answers
38 views

DS18B20 reading double after long use

I installed two DS18B20s on a pi almost a year ago. They have worked great until the last couple months. I am doing a bit of a stress test on them and have been polling them every second for almost a ...
2
votes
1answer
167 views

Take 5 images a second, triggered by motion sensor, switching between 2 cameras depending on time

I'm working on a project similar to a security camera with a Raspberry Pi NoIR Camera Module v2 and a FLIR Lepton 3.5 on a purethermal 2. I am somewhat new to this and am not sure how to proceed. ...
2
votes
3answers
571 views

Connecting multiple load cells Pi Zero W to read individual values

I have a project in mind where I want to measure the weight and position of an item on a shelf. The idea was to mount the shelf on a load cell in each end and then get the weight and ratio between ...
2
votes
1answer
176 views

working with sparkfun tmp102 temperature sensor over windows 10 IoT

I'm looking for help in communicating with the sparkfun tmp102 sensor via windows 10 IoT UWP app on a raspberry pi 2. I've already found this tutorial: https://jeremylindsayni.wordpress.com/2016/06/...
2
votes
1answer
710 views

UART pins not reading sensor output RPI3

This is my first pi project so im a bit new at this. Im trying to connect a senseair K-30 CO2 sensor to the pi via the UART gpio pins. This is the sensor I am using: https://www.co2meter.com/products/...
2
votes
1answer
162 views

Pi3 Interface to IR Sensor stays High

I am new to RPi and trying to trigger a camera with a motion detector. The motion detector reads High (1) all the time, so pictures are taken continuously. I had the IR detector working with an LED ...
2
votes
0answers
286 views

Latency on a Raspberry Pi camera

I'm making a flight controller and want to stabilize the x-y plane using optical flow, which requires almost instantaneous processing thus requires almost no latency. How much latency does the Pi ...
2
votes
0answers
216 views

multiple DS18S20 temp sensors without using 1wire

Can anyone tell me if it is possible to connect the multiple DS18S20 sensors to different GPIO ports and pull the temperature on different ports, as opposed to a single wire option where I can only ...
2
votes
2answers
1k views

How can I stop the overlay of images between my pi camera and FLIR camera?

Totally newbie here, I'm trying to do a project with the FLIR sensor and a Raspberry Pi. They provided me with some code that turns on both the Raspberry Pi Camera and the FLIR sensor and overlays the ...
2
votes
0answers
345 views

Motion sensor does not detect motion unless “shaken”

I have the following hardware: Raspberry Pi 2 Motion sensor (http://www.amazon.com/Great-Deal-HC-SR501-Infrared-Raspberry/dp/B00M1H7KBW) Female to female wires And followed the tutorial here: https:/...
2
votes
2answers
976 views

Analog input with MCP3008

I'm trying to connect a Turner C-Sense pCO2 sensor to an RPi2B using an MCP3008 ADC. The probe is powered via dedicated 9V inverter. The probe's analog output wires include a signal out (+) and AGND (-...
1
vote
1answer
81 views

DHT11 Temprature sensor makes raspberry pi go crazy!

I am trying to use the DHT11 sensor temprature and humidity sensor with my Raspberry Pi 4B. When I connect the sensor with my Raspberry Pi and turn it on, the red LED on it starts blinking and it can'...
1
vote
0answers
86 views

raspberry pi3 + fingerprint

I'm looking for a way to connect fingerprint scanner with raspberry pi3 using python. I'd like to use only gpio or hat (not usb) interface. I'm searching for a while without figured out, so I've ...
1
vote
1answer
47 views

Why Raspberry Pi Zero W is missing to log data constantly every second?

I'm doing a project where I want to record IMU (Inertial Measurement Unit) readings. I want to use pretty high sampling frequency and I'm using Raspberry Pi Zero W to send PWM signal of 800Hz to ...
1
vote
0answers
44 views

garage door sensors

I know I'm overthinking this.... I've set up a sonoff inching 4-relay smart switch to "press" the garage door "buttons" for my three garage doors. So far, works OK connected to eWe server. My ...
1
vote
0answers
42 views

Cant read both SPI Buses of Raspberry Pi 3B+

I want to read 3 analogue sensors simultaneously. I have successfully connected 2 sensors using a MCP 3002 A/D converter which is connected to CS0 of SPI 0 of raspberry pi and I have activated 3 more ...
1
vote
0answers
61 views

DS18B20 temp sensor works on Pi 3B+ but not Zero W

I have a breadboard prototype working with a cabled (waterproof and regular temp) DS18B20 sensor and a AM2302 sensor on a 3B+. All is well with it recording at a set interval from each sensor. I'd ...
1
vote
1answer
95 views

SW-420 Sensor/Code doesn't work--help with vibration sensor

I'm working on a project that uses SW-420 sensors to detect vibrations. I was originally following this tutorial and my code is pasted below. I used a previous post to determine that I should be using ...
1
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0answers
96 views

Why is my raspberry pi crashing? Reading DHT11 - Logging to text file with python

So, I'm pretty new to this. Want to play around with temperature & humidity sensors. I have a pi with 4x DHT11 sensors, on wires of ranging lengths hosted in different situations. I've written a ...
1
vote
1answer
1k views

Correct wiring for multiple analogue sensors?

I’ve recently embarked upon a project that I’ve wanted to do for a while. My overall plan is to have 3 planting shelves; each will have its own soil moisture sensor, water pipe and LED lighting. The ...
1
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0answers
89 views

GPIO commands for contact sensor circuit

I have a simple circuit that goes to a garage door contact sensor then to a resistor then to an LED to show if the circuit is open or closed. I've confirmed that my wiring works with a power source - ...
1
vote
0answers
394 views

Connect multiple sensors on a single USB to RS485 adapter

On tindie I bought a RS485 soil moisture sensor with a USB to RS485 dongle. I want to add more sensors for monotorring multiple plants. Since RS485 is a bus system, it seems basically possible to ...
1
vote
0answers
484 views

How to test IR sensor on OSMC?

I've tried to follow some tutorials on installing an IR sensor to GPIO, with the goal of using an old Xbox remote with OSMC. They basically say to connect it up to pins 1 (3V3), 6 (GND) and 12 (GPIO ...
1
vote
0answers
130 views

sound and flame sensor

SOUND_PIN = 4 FLAME = 2 LED = 26 LED2 = 18 PIR = 6 import RPi.GPIO as GPIO import time import datetime import os import picamera GPIO.setmode(GPIO.BCM) GPIO.setup(PIR,GPIO.IN) GPIO.setup(SOUND_PIN,...
1
vote
1answer
239 views

Using an Xbee on raspberry pi 3 model b

I'm a complete newbie to using Raspberry Pi (pi 3 model b). I want to build a smart CO and smoke alarm from scratch, I know what sensors I want to use ( Mq 2 for smoke and mq-7 for CO), however I want ...
1
vote
1answer
97 views

Magmatic sensor's error in MPU9150

I coded the following program to get the acceleration, gyro, and magnetic sensor values by using a MPU9150 that is connected to a Raspberry Pi 2 via I2C. I can get the proper acceleration and gyro ...
1
vote
0answers
134 views

Coin Cell Powered Bluetooth “water on floor” sensor(rope type)

disclaimer, I am quite new to development of solutions around the Raspberry PI, so please forgive If I'm slow at grasping something but, I'm trying to put together a package to implement across ...
1
vote
0answers
550 views

IR Tracking Sensor (TCRT 5000 ) always gives led off as output

I am using a Raspberry PI3 Model B and TCRT 5000 sensor to monitor movement. I am using a Python script(Python3) to read the data from the sensor. Script used - #!/usr/bin/env python import RPi.GPIO ...
1
vote
2answers
529 views

mq5 gas sensor not alerting of leakages

I'm currently using an mq5 gas sensor in my kitchen with the MCP3208 ADC. my code shows a continuous loop of the voltage charge. in the mq5 as it detects gases in the air. It is supposed to print ("...
1
vote
0answers
164 views

Use SPI to clock sensor and stream data using DMA

I'm looking into a issue on a Pi with SPI port, to clock continuously and stream data to memory area using a DMA. The sensor I connected on SPI on a Raspberry Pi 3, should be clocked with more than ...
1
vote
0answers
76 views

Multiple Touch Sensor

I am doing project for school: "Interactive Piano Highliter". One of the task is to check whether the key was pressed or not. Prototype consists of 20 keys, so I need 20 touch sensors. Do you know ...
1
vote
0answers
620 views

Ultrasonic Sensor HC-SR04 Lag Problem (20Hz only) in PID control loop

Good day, I am currently working on an autonomous quadcopter project. I am using the HC-SR04 sensor for altitude hold, however in testing the sensor, the maximum data throughput of the sensor is only ...
1
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0answers
689 views

long distance measuring modules - experiences: ME007-ULS V1

I am searching for a cheap non contact long distance (1 to more than 10 metres) measurement sensor with an accuracy <= 1cm. I'm already using the hc-sr04 ultrasonic in combination with the dht22 ...
1
vote
0answers
1k views

Image Processing With Windows IoT Core

I am a Newbie to Raspberry Pi Windows IoT core, I wanted to create a system to detect total number of Chairs/Tables present in a room for business, I researched a lot, I had a few sites stating that I ...
1
vote
0answers
462 views

Raspberry Pi 2 and DS1621

I am connecting temperature sensor, DS1621 with Raspberry Pi 2. Pin 5,6,7 and 8 of DS1621 is connected to 3.3V and pin 1 is connected to SDA, pin2 is connected to Clock and pin 4 is connected to GND. ...
0
votes
1answer
83 views

Connecting multiple sensors to Raspberry Pi 4 B

I have a Raspberry Pi Project in mind but I'm completely new to this matter and have literally no idea. My plan is to create a transportable Weather Station (which includes a temperature sensor, air ...
0
votes
0answers
21 views

How can we acquire an analog signal having both positive and negative parts , i.e. a bipolar signal, using Raspberry pi3 B+ module?

I am using raspberry pi 3 B+ board. I have to acquire analog voltage signal having both positive and negative parts, i.e. a bipolar signal How can i acquire this signal with the R-pi? I have tried ...
0
votes
0answers
34 views

HC-SR04 Ultrasonic Rangefinder readings are off by a large margin

I'm making a robot that should avoid obstacles and im using a HC-SR04 to measure distances. My problem is that my readings are off by a large margin. when there is no obstacle in the way I get a ...
0
votes
2answers
88 views

Making the VCNL4040 proximity sensor work on Python

I purchased the SparkX module with the VCNL4040 proximity sensor you can see here: to use this sensor via Python, but on the repo for the Adafruit library it seems like the library is not available ...
0
votes
1answer
49 views

Raspberry Pi share ppp0 via USB

I have the following setup: Raspberry Pi 3 Sixfab 3G/4G Base Shield v2 Queltec UC20 I have connection to the internet over ppp0 interface but now I want to connect the Instantel Micromate sensor to ...
0
votes
0answers
120 views

Read data from RPLidar and getting “Wrong body size”

I'm trying to read response from a Slamtech RPLidar connected to my Raspberry PI 3 via USB and I'm getting the following error: Traceback (most recent call last): File "app.py", line 70, in main ...
0
votes
0answers
56 views

Adafruit CircuitPython DHT22 reading exceptions

I am using the program from Adafruit's Circuit Python to read the values from DHT22/AM2302 sensor. At the start of the program, I often get the exception A full buffer was not returned. Try again. ...
0
votes
0answers
106 views

MQ135 Sensor - Output ppm

So I am making a Mq135 sensor and the wiring can be found on: circuit.io/app?components=9443,200000,398790 It isn't shown but the AO is connected to channel0 via the breadboard the code is : #!/usr/...
0
votes
1answer
158 views

Why is bme/bmp280 temperature and humidity sensor returning 0 value?

I'm having problems with bme/bmp280 temperature and humidity sensor on my raspberry pi 2. It does not give me feed back information. i have my ARM i2c protocols on and i wired it correctly but it ...