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.
0
votes
1answer
17 views
ESP8266-12E and MCP23017 , unable to identify the application
After googling much I have found that MCP23017 can be used with esp8266-12e for more number of output pins.
I have tried all the programs from different tutorials on internet but could not make it ...
1
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0answers
27 views
I2C wire.h send 2 variables
I am trying to send 2 variables with wire.h. I tried with this code:
MASTER RECEIVER:
#include <Wire.h> // include la libreria
#include <LiquidCrystal_I2C.h>
#include "RTClib.h"
...
0
votes
1answer
50 views
conflict I2C with 2
hi i have some trouble to connect my 2 arduino nano with i2c standard,
i have this configuration
SLAVE RECEIVER nano with DS1037 i2c and LCD 16x02 i2c
MASTER SENDER nano .
After some time the SLAVE ...
-1
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0answers
15 views
MPU6050 not working with Arduino UNO R3
I am trying to build myself a Self Balancing Robot using Arduino UNO R3, MPU 6050 GY-521 and L293D Motor Driver Circuit. I am also using I2Cdevlib for MPU Values. Initially in order to check whether ...
0
votes
1answer
41 views
I2C communication, wrong response
With reference from http://www.gammon.com.au/i2c I tried the example there. However I am getting the wrong response and readings. At startup the Master will request for slave address. I should get a ...
0
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1answer
12 views
SPIRead value changes as Wire.begin() is called - Looking for a solution
I'm working on a project where I want to send results of sensordata (Gyroscope/Accelerometer MPU6050) over LoRa.
Currently I got the code written to read the sensor and create a 'code' I want to send ...
0
votes
2answers
43 views
Servo motors not working when called upon using I2C
So I'm using this movement() function inside the slave Arduino Uno, which basically handles two stepper motors and one servo motor. When I call this function through the Serial.read() of the Arduino ...
0
votes
1answer
19 views
How do I stop 5v on the I2C port of a pro mini so I can use 3.3v devices?
The theory is that you can use 3.3v I2C devices from a 5v device as long as the pull ups are only to the 3.3v. I have a 5v pro mini connected to a bmp180 board which has a 3.3v regulator but no level ...
0
votes
1answer
30 views
Detecting I2C transfer with LED
I am going to do a project with a lot of Arduinos connected via I2C, where like of them can became master for a moment to announce an event. So I would like to see how much is the bus used. As there ...
0
votes
1answer
43 views
Multiple I2C sensors with the same address
I am trying to find the simplest way to connect multiple (preferably around 10-20) IMU sensors to one controller. There are two constraints: sampling at 60Hz and reasonably simple wiring as I want to ...
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0answers
33 views
Due to Some reasons Timer base music system has been stopped
Due to some reasons my system goes to stop. I could not find this problem so please help me with it.
I am making a timer based music system. I am using two Arduino boards which communicate with each ...
3
votes
2answers
124 views
I2C and SPI at the same time?
I would like to ask a question relating to the following communication setup:
STM32 -- Arduino Pro Mini -- ADNS3080 sensor
The interface between STM32 -- Arduino is I2C and the interface between ...
1
vote
1answer
38 views
PCA9685 seemingly no PWM output Arduino Uno when attempting to do LED dimming
Just for a quick test I've wired up the Arduino to a PCA9685 board (similar to http://www.ebay.com.au/itm/PCA9685-16-Channel-12-bit-PWM-Servo-motor-Driver-I2C-Module-For-Arduino-Robot-AU-/162059198475?...
0
votes
1answer
28 views
How to use potentiometer data from slave to master Arduino?
I'm trying to make a game where i can use one Arduino as a controller (the controller is a potentiometer) and the other Arduino sending the signals to the computer. Im trying to figure out ...
1
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1answer
29 views
Need to turn on project twice in order for screen to work!
This problem is really stumping me. I made a simple printed circuit board with an ATtiny85, a 128x64 I2C OLED display, and a Sharp IR analog distance sensor. You can view the circuit here: circuits.io....
4
votes
3answers
69 views
How to setup an I2C bus which stays valid if a slave is powered down or fails?
I have setup an I2C bus between 3 Arduinos (Master, Slave1 and Slave2) by connecting all 3 A4 pins together, all 3 A5 pins together and one GND pin of each Arduino to a common ground line. The 3 ...
0
votes
1answer
55 views
Does receiving data with SPI stop the main loop?
I have a loop of code running on a Mega 2560 that is running at a certain speed, which I get from an Arduino Uno. I have tried to talk with I2C but when I receive the data from I2C, the whole code ...
1
vote
1answer
37 views
wire.h onReceive only triggering once
I am writing a program to emulate a LCD driver chip (PCF8576) in a piece of equipment where I need to replace an unobtainable LCD display.
I have wire.h set up and the code in place to decode chip ...
5
votes
2answers
840 views
Which library to choose? <Wire.h> or “Wire.h”?
I know that in C++, to include a library, you either put the library name in <x> or "x". Now, I believe that this was because of a major change in the C++ language a some time ago.
Now, in ...
0
votes
1answer
52 views
Arduino and Raspberry Pi - initiate i2c communication as slave
I would like to interconnect Raspberry Pi and Arduino over i2c.
RPi will act as MASTER while Arduino is SLAVE.
I understand that i2c is designed that only master can send messages to slaves and then ...
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votes
1answer
25 views
Control multiple MPU9250 to start collecting data at the same time [closed]
Is it possible to use multiple MPU9250s for data acquisition at the same time?
I want to use 10 MPU9250s in human motion capture, but how make all MPU9250 work at the same time so that make the data ...
4
votes
2answers
85 views
Does an I²C IO Expander needs additional resistors for outputs?
I have following setup (see also schematic in the end)
Arduino Nano is connected via I²C to the PCF8575C (link) IO Expander.
Both, SCL and SDA have 10kOhm pull-ups to 5V.
The Expander pins are ...
0
votes
1answer
59 views
Arduino bug when “myFile = SD.open” is inside loop()
My Arduino resets / bugs each time I put myFile = SD.open in loop().
In setup() it works fine.
I have a 20*4 LCD and an RTC connected to I2C, an SD card reader connected to SPI, and a fingerprint ...
1
vote
2answers
34 views
Update Variable via Arduino to Arduino I2C
I am attempting to send a simple 1 byte value from one arduino to another using I2C with the Wire library. From reading I see that this is typically done using the event monitor supplied by the Wire ...
0
votes
1answer
39 views
SPI Overflow in 328 slave with i2c sensor
I am working on creating sensor poller that is going to be polling multiple sensors and then, on request, provides its data to the master.
The master polls the slave (SPI) at 50hz and the slave is ...
3
votes
1answer
88 views
I2C to UART bridge as breakout or in DIP package
For a project, I need to connect more than one device to an Arduino through a serial port with hardware flow control (RTS/CTS).
Sparkfun used to make breakout boards for the SC16IS750, but this ...
3
votes
1answer
54 views
I2C collision detection
I have put together a system that uses multiple Arduinos and a couple of 20x4 LCD displays to monitor my PV sun tracker and a weather station. I am using I2C to link them all together. One of the ...
1
vote
2answers
58 views
Problems reading I2C sensor when using a Xbee module
I'm developing a project where I can control a RC boat with GPS and a magnetometer. How ever, I was developing everything connected to my computer and worked pretty well. When I was going to make some ...
0
votes
2answers
36 views
Common/standard library and/or protocol for Arduino to be I2C slave for driving NeoPixel
I would like to control a string of WS2812/NeoPixels from a SBC like a BeagleBone or C.H.I.P. I realize someone has gone through the trouble to come up with a way to drive the WS2812 string from a ...
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1answer
40 views
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 ...
3
votes
1answer
115 views
I2C connection freezes Master if Slave disconnects
I am using I2C to successfully request critical data from a Slave device (I have to use requestFrom() in the Master) but if, for some reason, the power disconnects from the Slave device then the ...
0
votes
2answers
49 views
I2C on non I2C pins, possible?
I have 2 I2C devices that uses the same address. One of them is the DS3231 RTC. I use this library for the DS3231. I dont want to mess with the other one cause it is way more complicated then this one....
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2answers
112 views
Multiple I2C BREAKOUTS with pull-up resistors doesn't work [UPDATE]
[UPDATE] Now it works fine but the as soon as I add the GY-521 module (hardware not software), it starts sending me crapy info
Project uses:
Arduino Pro Mini as brain
FTDI as a programmer
GY-521 ...
3
votes
2answers
201 views
Soldering Arduino Pro Mini's disaligned pins
I have a couples of Arduino Pro Minis (original from sparkfun) that have those 4 disaligned pin. Unfortunetely, I need to use 2 of them, A4 and A5, because they are the I2C pins and I want to solder ...
2
votes
2answers
212 views
Difference between Wire.setClock() method and TWBR method for changing I2C Frequency
I want to change the I2C frequency of my Arduino Mega 2560. I did find two methods. One method is to change the TWBR variable after Wire.begin(). The other one is to use Wire.setClock() after Wire....
4
votes
2answers
263 views
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)
...
1
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0answers
116 views
How to prevent Wire.requestFrom from hanging?
I'm trying to read data from an Arduino Uno I2C slave via Wire.requestFrom() on an Arduino Uno master. The slave's onRequest handler is simply:
void I2C_Send()
{
byte myArray[4];
myArray[0] = ...
4
votes
2answers
147 views
Sending uint16_t over I2C
How do you transmit and read a uint16_t over I2C?
I'm trying to read two uint16_t values from a slave device, and I'm seeing nonsensical readings.
This is the code on my slave Arduino Uno:
#include ...
0
votes
1answer
54 views
How to make PCA9685 work with Arduino Due?
I have Arduino Due and PCA9685.
I use this library:
https://github.com/adafruit/Adafruit-PWM-Servo-Driver-Library
The board does not do anything with servo connected. I tried to use SDA/SCL pins and ...
0
votes
1answer
90 views
How to turn I2C Sensors on and off with an Arduino Mega 2560?
I want to turn on and off I2C Sensors with the Arduino Mega 2560.
I use one max. 0.4A NPN Transistor, which controls the Vcc line to the sensor.
When I plug my Arduino into my laptop and the sketch ...
1
vote
2answers
162 views
Controlling a capacitive touch screen that doesn't have I2C/SPI
I have been searching for cheap slim 3" 16:9 capacitive touch screens for a while now. But I couldn't find any that had an I2C or SPI interface. The cheap displays always have these ribbon cables with ...
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votes
1answer
34 views
How can I determine how many bytes an I2C master read from my Arduino acting as I2C slave?
I have an Atmega328 programmed using the Arduino software and libraries (but is standalone on on a board in the TSOP package) without bootloader and with ISP programming). I am using the Wire library ...
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0answers
237 views
Grove- Multichannel Gas Sensor - Arduino
I am connecting the Grove Multichannel Gas sensor with Arduino Uno like any other I2C sensor (Vcc, GND, SLA, SDA) and I am using the basic example of the library to read the gases concentration.
...
4
votes
2answers
171 views
Arduino I2C long string
I am trying to get 2-Arduinos passing data. The Master will request the data and the Slave send it. But, the length of the string the Slave will send is unknown each cycle.
I found some things here ...
0
votes
2answers
135 views
Arduino Wire.h library how to communicate with an LCD
I am having an Arduino Uno and an C2042A LCD with I2C shield on it. Because the virtualwire library does not work for me I tried only the wire library but it's still not working:
My Code:
#include &...
0
votes
1answer
61 views
Arduino which library for led 4x20
I am having an Arduino Uno and I want to add a LCD to it. My LCD is a C2042A with I2C shield on it. I tried the LiquidCrystal_I2C library but it doesnt work. I am not getting any errors the LCD is ...
1
vote
2answers
55 views
Delaying pushbutton input to microcontroller while it's busy processing I/O
I am trying to create my own home automation using Arduino. I am using shift register for reading input(via push buttons) and writing output to led's. I am using SPI interface to communicate with ...
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0answers
19 views
Inexpensive way of connecting a lot of modules on a distance
I need to connect a lot (~100) of modules with a computer (Raspberry pi). The modules are based on Arduino micro and are very simple. They will be spread around, but for the two adjacent the distance ...
0
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0answers
22 views
Newbie question with HC-SR04 and OLED
Nothing more humbling than taking up a new hobby (in this case fiddling with Arduino).
I have a ultrasonic range detector, and a little OLED display. Simple start...measure and display distance.
I ...
4
votes
1answer
106 views
Arduino as a custom I2C slave device
I'm trying to interface with a master I2C device that doesn't exactly follow the normal I2C protocol.
The only difference really is in the read request. A "normal" I2C read operation looks like this (...
