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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Strange problem. Arduino stops working after few hours. Opinions please
I am trying to setup an automated relay for my aquarium. The Arduino should switch off the pump every 3 hours for 20 minutes, and feed at particular times during the day. The code works fine for the ...
3
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2answers
65 views
I2C LCD displaying weird characters
I have connected an LCD with an I2C backpack to my Arduino Uno but it prints the wrong characters. The weird thing is that it worked fine for a while and when I updated the code (but didn't change ...
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1answer
13 views
Where am I supposed to get an I2C BUFFER_LENGTH defined?
I am using a BLE nano - as soon as I try to include I2Cdev.h and compile, I get this error:
Arduino\libraries\I2Cdev\I2Cdev.cpp:276:62: error: 'BUFFER_LENGTH' was not declared in this scope
How ...
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0answers
41 views
MPU 9150 connected to Intel Edison (Arduino) slows down after a few seconds
I have MPU 9150 connected to Intel Edison(Arduino).
The program below initializes and gets some data from MPU using I2C. The problem is weird. It starts and works fine for several seconds. After that ...
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1answer
26 views
TEA5767: Wire.endTransmission() hangs
I'm trying to get a TAE5767 (FM radio) to work. According to this instructable I'm trying it on a 5V-Olimexino 32u4 (Leonardo-compatible) with following code (Arduino 1.6.3):
#include <Wire.h>
...
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26 views
Arduino (or Breadboarduino) as I2C slave
I have a somewhat complex setup in which a number of sensors are queried, their results processed and then displayed. For various reasons, I don't want all of this to happen on a single 'duino. So I ...
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1answer
40 views
Arduino UNO inconsistent I2C register reading from ArduCam
I have an Arducam hooked up to an Arduino UNO. The code I am running looks like this:
#include <Wire.h>
#include <ArduCAM.h>
#include <SPI.h>
#include "memorysaver.h"
const int CS ...
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1answer
25 views
I2C connection with MT9D111 camera module, strange results after writing registers via i2C
I am currently working on a camera platform based on the MT9D111 module from Micron. The first thing to do is to write the configuration to the numerous registers of the chip which is done via an i2C ...
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33 views
Too many Bytes Using Ultrasonic Sensors
I need to send one transmission and record multiple distances with 4 receivers, but everytime I use more than 2 receivers, the serial data does not print. What can I do?
P.S. I'm using 5 SRF-02 ...
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0answers
63 views
ATtiny85 + HC-05 + Oled = smart watch
I am using an ATtiny85 for making a smart watch. Bluetooth module HC-05 with ATtiny85 pins PB3->TX, PB4->RX and it works. Secondly I have connected a 0.96" OLED on PB0 (SDA) and PB2 (SCL) and this is ...
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1answer
36 views
Configuring IO18, IO19 for I2C connectivity on Intel Edison Kit for Arduino
Intel Edison Kit for Arduino Hardware Guide instructs:
echo 28 > /sys/class/gpio/export
echo 27 > /sys/class/gpio/export
echo 204 > /sys/class/gpio/export
echo 205 > ...
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1answer
35 views
Modifying Arduino IMU library to rely on DSSCircuit's I2C Master Library
For an Arduino project I am working on, I am trying to modify the SparkFun 6 Degrees of Freedom IMU Digital Combo Board - ITG3200/ADXL345 to support DSSCircuit's I2C Master Library ...
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4answers
339 views
Weird problem with LCD 16*02 I2C shield
I have an I2C LCD screen provided with a Sunfounder kit and certainly built by DFRobot or such a constructor (there is nothing written on the LCD), and an Arduino Uno R3 copy.
My issue is when I use ...
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1answer
21 views
I2C between Arduinos without Master
I am working on a library for some Arduinos that should talk between each other.
The aim is that I can load the same binaries onto each Arduino. The I2C ID will be set by DipSwitches.
So far ...
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2answers
269 views
How to display variables on 0.96" OLED with u8glib library?
I have Arduino Uno and 0.96" I2C Oled 4 Pinned display. These are my Arduino codes:
#include "U8glib.h"
U8GLIB_SSD1306_128X64 u8g(U8G_I2C_OPT_NONE); // VDD=5V SCL=A5 SDA=A4
int a = 10;
void ...
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2answers
55 views
Can I safely integrate 3,3v sensor with 5v Arduino UNO? How?
I plan to use Adafruit's RGB sensor with Arduino working as a RGB controller running on 5V. In my location, the 5V-compatible version of the sensor is not available.
There is a 3,3V pin on my Arduino ...
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1answer
42 views
LCD Pin Numbering vs I2C Controller Pin Numbering vs Sketch
I've been playing with an Arduino Uno, trying to get a 16x2 LCD screen to work with an I2C controller. I've got this LCD screen and this controller. And I've been trying to get the sketch below to ...
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0answers
28 views
I2C — set int pin
I am using a blend micro board, where the digital pins 4, 6 and 7 are reserved.
I have connected a MPU6050 which uses the I2C protocol, so there is the need for the i2cdev lib to handle that.
The ...
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0answers
31 views
Teensy and MS5803 sensor
I'm trying to use the MS5803 pressure sensor with a Teensy 3.2. Compiling the Sparkfun, or other, libraries, however, results in no output.
Can you provide guidance on how to modify the libraries to ...
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2answers
35 views
What is the purpose of the howMany integer in the wire.onReceive() function from the example code?
In the master write/ slave read example for the wire library, there is an integer declared howMany that is never used.
void setup() {
Wire.begin(8); // join i2c bus with address #8
...
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1answer
31 views
Arduino Wire.onReceive(handler)
its says in the description of the function:
Registers a function to be called when a slave device receives a transmission from a master.
So when does it exactly called? i guess its not been called ...
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1answer
28 views
Arduino Uno and I2C
How does the arduino uno talk with i2c? i saw the circuit and it use analog input pins but as far as i know you cant use them as output. How does he send data over those pins?
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1answer
65 views
I2C_Anything String / Char Array issues
I've been working with the lovely I2C_Anything.h (thanks to the great work and support from Nick over at http://www.gammon.com.au/forum/?id=10896&reply=9#reply9).. All working great, I was using ...
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64 views
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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1answer
18 views
Is it possible to specify a pin upon which the data sent over i2c can act?
A master will send fan speed values to the slave. The slave will then read the fan speed values and change the speed value for the relevant pwm pin. However I am not sure how I can tell the slave ...
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1answer
40 views
Switch MPU6050 to send SCL data through A4 and SDA through A5
I have this MPU6050, and like most of the other MPU6050s, it is set up for SCL to be attached to A4 and SDA to be attached to A5. I have this shield on my Arduino Uno, which is configured for ...
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0answers
18 views
How can I send a number from a master and make the slave read it?
I am building a fan controller using an arduino and a raspberry pi (the raspberry pi is the master and the arduino is the slave). The raspberry Pi generates random numbers and I want the slave ( ...
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0answers
24 views
many other address (3)
I'm trying a project with 3 slaves (send data) and 1 master (read data) and I can do it with 1 byte (send data = 255) with all interacting together but with the other sketch with send 2 bytes (send ...
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1answer
45 views
Connect 2 LSM9DS0 to Flora
So I'd like to connect two of these sensors to an Adafruit Flora (https://www.adafruit.com/products/2020). In the product page it says you can only connect one but in the forum an admin said that you ...
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3answers
35 views
Arduino wire can't send char
Hi I have problem with school project. I have 3 Arduino - 1 Transmiter with NRF; 2,3 - NRF receiver and wire slave receiver.
I can't send data via "Wire" library (in code char "datar") to receiver ...
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1answer
67 views
I2C Master send reset command to the slave counter
My name is Gianni, I live in Olbia Sardinia Italy and I have some experience in electronics.
For several years I have been passionate about Arduino.
They are now engaged in a project to counter with ...
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2answers
760 views
Sending and receiving different types of data via I2C in Arduino
I have found a few good tutorials on how to send and receive data via I2C in connected arduinos. My limitation is now how to transmit different types of data like for instance, long, float, etc. Right ...
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2answers
73 views
What is an I2C address of a sensor?
I have connected BMP180 sensor
to Arduino and was able to read it's values with appropriate samples (from Adafruit BMP085 Library and Adafruit BMP085 Unified).
Apparently, this sensor is sending ...
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1answer
61 views
Unexpected output form Serial.println
So I have a teensy and an arduino uno connected together via I2C, however some very odd behavior is occurring, when monitoring the serial connection for shorter data sent over I2C I receive the ...
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1answer
45 views
Function not successfully reading sensor registers
I'm trying to write a library for an accelerometer/magnetometer sensor. The sensor is a LSM303D chip (https://www.pololu.com/file/0J703/LSM303D.pdf).
I've written a function, readRegister() (below) ...
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0answers
27 views
Basic communication between Cotek and Arduino UNO
so I am trying to get a reading from my Cotek through my arduino and have it display on an LCD screen. When I run the code, though, nothing shows up. I am EXTREMELY new to using pretty much all this ...
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0answers
247 views
Protocol options for data exchange between Arduino and ESP8266
I have a device built with an Arduino uno:
Arduino software installed on an Arduino uno
can be controlled via serial commands
can be controlled via physical buttons and sensors
on any button/sensor ...
0
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1answer
494 views
ESP8266 as i2c client
I've got an ESP8266 that takes instructions from a web page and sets a series of NeoPixels to flash in different sequences.
I noticed that when the WiFi got data and parsed it, my LEDs would "stutter" ...
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0answers
84 views
Use AS3935 with I2C?
Has someone experience with interfacing the AS3935 lightning sensor using I2C? I found a library but it only works with SPI as far as I can tell. I really don't want to give up 4 pins for SPI as I ...
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1answer
55 views
How to wirelessly communicate with I2C infrared thermometer
I've been getting involved with arduino recently as a means of improving a heating device which is quite small, a box about 15x10x5cm which I would like to rig with an MLX90614 infrared sensor.
The ...
0
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1answer
61 views
Arduino messing up as slave over i2c
So I have an Arduino Mega2560 and a Raspberry Pi hooked up through i2c. The pi is acting as the master while the Arduino is the slave. While sending data over I2C the int message gets messed up and ...
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1answer
87 views
unresolved overloaded function type for Wire.onReceive
I am attempting to make an I2C slave out of my Arduino and I can't get past the Wire.onReceive function. Here is my code. The documentation says to just add a function that has the style of void ...
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1answer
97 views
MCP23017: 16x2 LCD showing black boxes
I've researched a lot but I couldn't find a solution to my problem, which is that after properly following all steps from this Website: ...
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1answer
58 views
Use TSL2561 and DS1307 RTC together
I want to use a TSL2561 light sensor and a DS1307 RTC and a couple of other sensors like DS18B20, AS3935, ML8511, MQ135, 433 mhz sender together with an Arduino.
However on Adafruit I read this today ...
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1answer
281 views
Arduino Due and BNO055 address in i2c mode
I have a project where I need to have several IMUs, the BNO055 shuttle board (I explained my project here), I manage to get the Euler angles from one BNO055 sensor, which have the address 0x29, ...
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1answer
114 views
Using union to return a range of bits from a data frame: wrong approach?
I'm working on an adaptation of Jason Leyrer's Guitar Hero Library for Arduino. My version is for a DJ Hero controller, and I've also borrowed some code from this Arduino forum thread: topic=120527 ...
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1answer
175 views
Software I2C - Atmega8
I am using Atmega8 with 12MHz crystal, on my breadbord. I can use SDA and SCL pins with default arduino library wire.h, and it works. But I want another pins to use I2C protocol.
I tried library, ...
3
votes
1answer
1k views
How to connect new OV7670 FIFO to Arduino?
I bought a new OV7670 FIFO camera to connect to my Arduino UNO a few days ago.
The picture of the cam board:
I found this forum, it is nice try but it looks chaotic and confusing with about 50 ...
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2answers
112 views
How do you send data via I2C without the wire library?
I have the following digital potentiometer: DS1803-100 which, according to the datasheet, can be controlled using a two-wire serial interface. I have managed to get it working using Wire, however I ...
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2answers
576 views
Disabling i2c internal pull up resistors
How do you do this? I've been digging around and I can see that I should do this and supply my own external pull up resistors but I don't know exactly how to disable them. The pages I've been reading ...
