I assume you have not connected anything to those inputs. The inputs will therefore be floating and return random results.
It's probably simplest to connect unused inputs to ground if you do not like this behaviour.
I recommend this repository for ADS1115 for RPi in Python and for Arduino.
Read the values
You can adapt to your project and works properly.
* @brief Init The Analog pH Sensor
* @brief Convert voltage to PH with temperature compensation
* @param voltage : Voltage ...
This is normal. ADC inputs are made very sensitive on purpose, and will work as antennas picking up all kinds of noise when not connected to anything. Periodic noise can usually be traced to your mains voltage, which you can confirm by sampling the pin 200..500 times per second.
There is only one thing to bear in mind. Only feed between 0 and 3.3V to a Pi GPIO. Anything outside that range will eventually damage the GPIO and then the Pi.
You have to consider each device you wish to connect on a case by case basis.
Generally if a device is powered from 3V3 its outputs will be a Pi safe 3V3.
Generally if a device is powered from ...
Based upon this discussion regarding interrupts, it would appear to be very possible to handle something that is 0.1-0.5 kbps.
As with many things on this platform, there are many potential ways to make this happen. From the simplest to the most complex, one could do this with pigpio or one could code a kernel module to function as an interrupt service ...
Previously the kernel would automatically disable interrupts when you set one of rising/falling edge detection methods but that apparently stopped happening, causing a kernel panic.
See this post for more details.
The Raspberry Pi does not have any analog input PINs. Thus you will not be able to interpret analog input signals without some additional hardware.
In order to be able to read not only HIGH or LOW levels from your sensor, you need to use an analog-to-digital converter (ADC), e.g. in the form of a ADC-HAT extension for the Rasperry Pi. Then you can connect ...
There are a lot of potential ways to do this. Based on this answer I'd suggest this:
simulate this circuit – Schematic created using CircuitLab
What's shown in the schematic as a 20M ohm resistor is actually just two wires which are about 1cm apart. They should be arranged so that they just touch the water when the water gets to the desired level. ...
I would suggest 2 changes. Firstly it is possible that the program can get stuck in the while loops so add a timeout. Secondly initialise the pulse_start and pulse_end variables incase the while loops don't get entered. This could be improved to ignore results where the timeout has been used.
import RPi.GPIO as GPIO
I figured it out with a little help:
Circuit Python doesn't work with this sht21.py, because it is smbus based. So here it is:
I used the multiplexer code from this homepage but this is all I needed
# TCA9548A I2C multiplexer
# I2C Address: 70 through 77
# Channel: 0 - 7
# class for the I2C switch
This can be good start for you. This example gives the time and distance calculations. You can trigger the Image capture of camera with your specified time.
From How to use a pH sensor with Arduino
Calibrate the sensor
As we can see that there are two potentiometers in the circuit. Which
it is closer to the BNC connector of the probe is the offset
regulation, the other is the pH limit.
Offset: The average range of the probe oscillates between negative and
positive values. The 0 represents a ...
Q1. How to adjust offset？
A1. Following Part1 Section 1,
(1) Power supply 5V to module,
(2) Do the 3 offset calibrating steps until your multi-meter read about 2.5V.
(a) For offset calibration, you don't use any liquid sample. You just
short the BNC plug input (centre) to ground (outside sleeve), ...
I would connect SDO to ground. This ensures the ADXL345's I2C address is 0x53. If you connect SDO to 3V3 the address will be 0x54. It may float between the two if not explicitly set to ground or 3V3.
I would connect CS to 3V3. This ensures the ADXL345 is in I2C mode. If it is ever low the ADXL345 will enter SPI mode.
Other than that I am out of ideas ...
I used to measure temperature on the Raspberry under different load.
I remember if you used something on the USB port, or the ethernet, the chip driving USB and ethernet becomes hotter than the CPU.
(I have a 3B+) But this should be true on the 2B. Anyways, the differences will be very very tiny.
Try find an infrared thermometer if you want to be sure ...
You've got one channel connected and the rest of the pins floating. Those pins that are floating are, well, floating, and there's not reason to think they should have any value in particular nor that whatever value they have will remain constant. That's not "noise" in any usual sense of the word because noise is usually with reference to a signal and those ...
You seem to be trying to read each sensor at the same time. That will not work (did the echo come from the sending sensor or another one).
You need to fire each sensor in succession.
I.e. rather than
trigger A, B, C
get echo A, B, C
calculate distance A, B, C
get echo A
Calculate distance A
get echo B
Calculate distance B
I personally would change your functions to be pir.isThereMotion() that returns true/false then you could do
filename = "pircam-" + datetime.now().strftime("%Y-%m-%d_%H.%M.%S.jpg")
This way it will just take a picture ever second while ...
You should move the camera initialisation stuff outside the while loop.
from gpiozero import MotionSensor
from picamera import PiCamera
pir = MotionSensor(4)
camera = PiCamera()
camera.rotation = 180
camera.start_preview(fullscreen=False, window = (50, 25, 640, 480))
The sensor that you are using has 3 lines from the MICS6814 air quality sensor connected to the ADC which is ADS1015 and this is what is connected to the Pi over I2C.
I do not think you can read from this ADC directly from the shell however there are python scripts available to read from the ADC. You can install the python libraries here and try out this ...
I'd look at somethign like Motion https://motion-project.github.io/ to watch the camera stream and save the image if motion is detected in view of the camera. Motion can read the pi camera.
Getting the detected speed from a sensor and writing that value onto the image as an overlay would make it look more professional.
Saving images of vehicles that ...
@joan's answer contains excellent advice. My answer simply expands on that one to provide some other options, and address your question re I2C usage:
Interfacing Raspberry Pi's 3.3V GPIO with the "outside world" often adds a hardware hurdle. This is partly due to the fact that much of the outside world operates at 5.0V. Interfaces to the outside world ...
Yes, you can use both sensors at the same time on the Raspberry Pi.
The DHT11 uses just one GPIO to trigger a reading and return the result.
The MQ-X sensors return an analogue signal and require an ADC (Analogue Digital Converter) to be read by the Pi. Typical ADCs use the I2C bus or the SPI bus on the Pi.
You need to choose solutions for both devices ...
I found the solution to this problem:
First of all read @joan 's answer for an explanation as to why the error occurs.
Secondly, run the following code: sudo i2cget -y 1 adress <-- adress needs to be replaced by what is in your table with the i2cdetect command as shown below!
In my case the adress is 0x68, the command will return something like 0x83 (...
The bus address is 1 (as in the 1 used in -y 1).
The command sudo i2cget -y 0x68 0x68 is saying read device 0x68 on bus 0x68.
0x68 hex is 104 decimal, which is why it complains about the non-existent bus 104.
I presume you mean to enter sudo i2cget -y 1 0x68
The dependency on GPIO is an artifact of the TSL2561 python library referenced above. The one I was trying to use has the dependency on Adafruit_GPIO, which introduces complications when also using rpi.gpio.
However, with more searching I found this TSL2561 python code in ControlEverythingCommunity that only imports smbus. As correctly noted by @joan, there ...
This appears to be an adaptation of a buggy Python script.
Personally I'd use it as a test to distinguish between people who can program and people who can script.
while(gpioRead(ECHO) == 0)
startTime = gpioTick();
while(gpioRead(ECHO) == 1)
stopTime = gpioTick();
What is meant to happen is a sonar trigger is sent and then ECHO remains ...
Yes, please be careful working with mains voltages as they can be lethal ! Ideally, all of your mains wiring to the relay should be in a separate enclosure that's properly grounded. If you're unsure about how to do this, please do your homework or ask questions here.
As far as the photoresistor module controlling the relay state; the key is understanding ...
Patterns used on a given platform are conditioned by its userbase. Most novice users will find the concept of a loop much easier to understand than the concept of events, let alone multithreading.
Typical UI applications are based on the same kind of infinite loops processing incoming data. The only difference is that the loop itself doesn't belong to the ...