Questions tagged [i2c]
Inter-Integrated Circuit (I²C) is a bus for low speed peripherals. Use this tag for questions regarding how to use I²C with an Arduino, or for problems with I²C and your Arduino.
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Standalone DS3231 i2c lost [closed]
I'm a little bit confused with the behavior of the I2C of DS3231. Watching the SQW pin at the oscilloscope and firing an alarm it does what is expected to (pulled low and high again). If I remove it ...
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I2C communication stuck
Working with a LTC2606CDD#PBF 16 bit DAC. I cannot get any voltage out.
I found this library https://github.com/rambo/I2C
I2C scan reveals.
Master Address 0x73
Slave Address 0x10
Here is my code.
#...
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Random artifacts on SSD1306 OLED screen
I'm having a really strange problem with my screen. It's connected in i2c to my Arduino Nano and I'm using a rotary encoder to navigate through a menu.
At startup everything is fine, but when I change ...
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Unable to find/connect I2C devices (SHT31 & SGP30)
I have recently purchased an Arduino Nano 33 IOT together with two sensors:
Adafruit SHT31-D (https://learn.adafruit.com/adafruit-sht31-d-temperature-and-humidity-sensor-breakout)
Adafruit SGP30 (...
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6 Pin BME280 Not giving 12C Signal
I'm Creating a telemetry package for my my mom model rocket with a MPU6050, a BME280, and a SD reader/writer. All code I found for the BME does not read any information. When I upload an I2C checker, ...
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Arduino Wire library master reader, slave sender example not working
I tried i2c EPROM and that worked pretty fine with arduino master. then i wanted to establish i2c communication between 2 arduinos such that both exchange each other's sensors data. I am not able to ...
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I2C requesting more than one byte
I got an Arduino Uno set up as an I2C master to an ATtiny85 slave, using the Wire (Master) and TinyWireS (Slave) libraries.
Communication works well. I have been able to keep the network running ...
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variable 'LiquidCrystal_I2C lcd' has initializer but incomplete type
I have a problem with lcd, I have NUCLEO64 L746RG , I have Lcd Display and I2C connected to it.
When I verify code it gives me and long error and I can not find the solution or cause of this error:
...
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Two Arduino boards with I2C sensors
I am new and lost. I have been searching the internet about how to transfer data of multiple sensors from one Arduino to another using I2C but no luck. All the codes and tutorials online focus on ...
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Capacitance from AD7746 always "saturated"
I'm trying to use AD7746 with an arduino board to continuously measure capacitance (I'm currently using a 2pF capacitor for testing).
Datasheet here.
I managed to correctly write and read the ...
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how do I wire a 2nd Adafruit TMP117 board to my Adafruit Metro by I2C?
I want to connect two TMP117 boards to one Metro (ie. Arduino).
(the first, addressed at 48 the 2nd at 49.)
Should 2nd board's 4 wires simply attach (ie. solder) in parallel to 1st board's 4 wires?
(...
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NodeMCU V3 and MPU6050 strange values
I am new to this platform, so please if I do something against the regular rules please let me know so I can learn.
Now my problem: I have a nodeMCU V3 connected to a MPU6050. Using my Arduino Uno I ...
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Can you coax another I²C connection out of an Arduino Nano Every?
I'm looking to network a bunch of devices (boards in a Eurorack case) over I²C, but I don't want to compromise the address space available to each individual device for its own needs. The obvious ...
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It is any DS2482 I2C to 1-Wire bridge functional library?
Please let me know if you know any good library for DS2482 I2C to 1-Wire bridge.
I tried to use https://github.com/cybergibbons/DS2482_OneWire library but I got errors when I'm trying to run the ...
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Cannot call function in call back for onRequest()
I am a NOOB! Trying to use the ZS-042 RTC module to retrieve the current time and send it back to the RPi over I2C. I can call the function and spool it to Serial but when I try to call the function ...
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Raspberry Pi, Teensy and Arduino's on i2c
I just got into an interesting mess.
I have 3 Arduino's (Pro Mini's) and 2x Teensy's (3.1's) connected via I2C to a Raspberry Pi Master. The 2x Teensy's I2C data lines are connected via OctoBoards ...
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Can't read through I2C from RTC
I'm using an ESP32 which I connected to a MAX31329 RTC through I2C.
Unfortunately I can't read any register from the RTC. After modifying the MAX31328 library didn't work, I tried reading single ...
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Reading I2C registers as slave device
I need to read the registers of a message gotten from onReceive(). I read here that
There's nothing "magic" about the register pointer: it's simply the first data byte in the packet. So ...
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Help with 1-Wire to I2C translate
Please, someone.
I want to use a temperature sensor (DS18B20) in an I2C only shield (Tentacle Mini), but this sensor is One Wire only. Can I write an I2C code to change the 1-Wire to I2C for this ...
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Is it possible to program an AVR chip (atmega328p) via i2c?
Currently I am using avrdude and I'm programming my atmega328p chip via the spi pins by pulling the RESET pin low (spidev programmer).
In my project I'm using predominantly i2c and this the only place ...
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Arduino Uno freezes for unknown reason during code execution
I am struggeling with a behaviour of my Arduino I do not fully understand.
Long story short:
When starting the communication over I2C the Arduino freezes. In my opinion during the "Wire.write()&...
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TTGO TS I²C adress
I'm working on a project using TTGO TS wich communicate wih arduino via I²C protocole
How can I find the adress of TTGO TS board used in I²C communication ?
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How to send an array of unknown size via I2C (from slave to master)?
When I try something like this, everything works.
Slave:
# define DEFAULT_DATA_SIZE 256
byte DATA[DEFAULT_DATA_SIZE];
void requestEvent()
{
Wire.write( (byte*) DATA, sizeof(DATA));
}
void ...
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Pca9685 & WS2818B, 1 Nano
Arduino n00b here. I currently have an Arduino Nano set up to run 6 servos from a PCA9685 board. I'm looking to add 6 switches and 6 LED indicators to switch servo positions. What I'm curious about is ...
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Getting inverse values of acceleration and tilt for the MPU 6050
I'm using the I2C library to connect to a GY-521 board and, when executing the getAcceleration() methods I get gyro values and viceversa..
This is my setup (I'm using a proto shield but that shouldn'...
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Multiple unique I2C devices interfere
I'm trying to make a fairly simple program that interfaces with the Adafruit TSL2591 light sensor as well as a MAX30102 pulse oximeter. They both use I2C for communication. I'm using the recommended ...
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Reverse engineering an i2c signal
I have an i2c device that i would like to rreverse engineer. Using the oringal master of the device here is a snapshot from the logical analyzer
I would like to replace the orginal master of the ...
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Can't get MMC3416xPJ to work
I needed a magnetometer with a high Output Data Rate (ODR). This is because I wanted to measure AC magnetic fields of around 20-80 Hz. So I decided to go with the MMC3416xPJ prototyping board which ...
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ATTiny85 I2C LCD
My setup is as follows:
Arduino IDE 1.6.11
Arduino Pro Mini as ISP
ATTiny85 1602A LCD with I2C board
The libraries I use are:
TinyWireM (source: https://github.com/adafruit/TinyWireM)
...
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I2C HMC5983 communication issue
I have a really weird problem, when I run the exmple wire (I2C) scanner from Arduino, I get:
I2C Scanner
Scanning...
I2C device found at address 0x1E !
done
However when I try directly to the 0x1E I ...
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Arduino outputting 4.7V instead of 3.3V when using I2C communication/sensor?
TOF050C-VL6180X Sensor was not responding, so I checked it with a multi-meter, and the VIN, GND solder pins on it read 4.7V. Double-checked Mega voltage, without anything connected, and it shows ...
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Wire.requestFrom() not a blocking function, even though it should be(?)
I'm working on creating a simple ACK/NACK handshake between 2 Arduino's that will essentially go like this:
Arduino 1 signals Arduino 0 it is available
Arduino 0 sends a connect byte to Arduino 1 (...
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Is it possible to use multiple I2C sensors with Arduino without an I2C multiplexer?
I have an IMU sensor and a Bluerobotics temperature sensor, both have different I2C addresses.
I want to integrate both with an Arduino UNO, I know I can do this with an I2C multiplexer but I don't ...
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How do I use I2C from an Arduino Uno when I have a GSM shield mounted?
This may be an extremely obvious question but I don't seem able to find a definitive answer.
I have an Arduino Uno and a Sim900 GPRS/GSM shield fitted on top of it. I had I2C working on the Arduino ...
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Is my BMA421 locked up?
I have been trying to set up the BMA421 motion sensor in a nrf52 based smart watch, using the datasheet for the BMA423, which has the same interface. I had got the sensor working well with the ...
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Serial communication between multiple devices (or Arduinos)
What I know from my search on the internet, for both SPI and I2C protocols, communication between multiple devices needs a master, which initiates the communication, and slaves, which respond to the ...
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How can I force an I2C module (for 1602 and 2004) to work with a 1601 LCD at my Arduino Micro
I'm new to Arduino and want to build a Button Box. When I buyed the parts I didn't watched out for the specifications of the I2C module. When I tried to print sth on the LCD nothing happened (in retro ...
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Using an I2C barometer
When buying a barometer for my current project at work, I chose the MikroElektronika click 3 barometer. However, as it turns out, the library for it doesn't exist for Arduino.
I know it uses I2C ...
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MAX30102 showing Heart rate: 0.00bpm / SpO2: 0%
I am using a MAX30102 to monitor SpO2 and heart rate using the https://github.com/oxullo/Arduino-MAX30100 library and the minimal example, but it is not showing any value change.
It only shows zero ...
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Connect arduino nano and ESP32 with I2C on the GPIO7 and GPIO8?
I made a mistake connecting SD0 (GPIO7) and SD1 (GPIO8) with the SDA and SCL on my arduino nano. I got confused with GPIO21 and pin21 and GPIO22 and pin 22!
Since I made a PCB prototype, I would ...
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I2C protocol doesn't work properly
I am trying to make I2C Communication between NodeMCU and arduino Uno boards. However it is not working properly. It makes communication for once time when i uploaded code.
Master Device Code(NodeMCU ...
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MPU6050 does not give output
I need help getting my MPU 6050 to actually give me data. As of right now, my program is only reading 0s from the gyroscope and when I move it, the values all go to -1 and the program just stops until ...
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I2C_anything from Nick Gammon. Value of two senders to be received and printed by receiverslave
Following the suggestion of Fiendish to post here:
Hello
Nick, thank you very much for this I2C-anything library that works a treat with two arduinos (one sender, one receiver).
Is there any suggested ...
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Recommend an Arduino Uno shield to monitor the state of 5 DPDT electrical switches
I have a project where I need to monitor the state of 5 DPDT electrical switches with Arduino Uno. Also, the Arduino board will be measuring the output from 3 thermocouples on 3 of the analogue pins ...
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Send values from Arduino Uno to Wemos D1 R1
I have a weather project in which I have to measure the temperature and humidity (DHT22 sensor), the pressure, and other things, and then show them on a local web page (using a Wemos D1 R1) in either ...
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Arduino I2C maximum number of writes per transmisson
Is there any limit on the number of Wire.write() commands consecutively in between the Wire.beginTransmission() command and the Wire.endTransmission() command for the Arduino Wire library?
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Problem with messuring capacitance with 50 Arduinos connected by I²C
I want to measure changes in capacitance over time. One Arduino is used per capacitance sensor. There is one anode per Arduino and a total of one common cathode (see the picture)
With four Arduinos ...
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Why are raw data bytes not converting to ASCII, but only in one part of my program?
I am writing a program to read from the Atlas Scientific EZO-HUM, -O2, and -CO2 sensors simultaneously via the I2C protocol with an Arduino Uno. The sensors all work, but for some reason, just the O2 ...
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HD44780 display incorrectly black-on-blue instead of white-on-blue
I have a generic HD44780 compatible 16x2 LCD display, with an already soldered on PCF8574 module. Its backlight is blue, and the characters are supposed to be white (on blue).
It is connected to a ...
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ESP8266 soft resets when using a GPIO Expander
In my project I'm trying to use a PCF8574 to drive some peripherals, since the ESP8266 doesn't offer all the GPIO pins I need, however I seem to be having problems at the most basic level of driving ...
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