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
22 views
How to request data via I2C?
How do you program an Arduino Uno to request data over I2C, sending parameters defining the request?
I'm trying to program Arduino A to read a sensor value from another Arduino B, and it first needs ...
0
votes
1answer
14 views
DS1307 RTC not working with CC3000 WiFi shield (I2C bus hangs)
I am trying to use a DS1307 (from Sparkfun, BOB-12708) with an Arduino Leonardo. I have connected the SDA, SCL, GND, and 5V pins from the RTC to the Arduino. However, with a CC3000 WiFi shield on the ...
0
votes
1answer
41 views
Second I2C address not accepted
I have set up 2 DHT22 sensors and 2 BMP280 sensors with an Arduino Uno SMD R3 board. The DHTs are working fine and are outputting correct temperature and humidity values to the Serial monitor. The ...
3
votes
1answer
26 views
Can't retrieve data from X-NUCLEO-IKS01A1 using I2C protocol
So I bought this nucleo expansion board, the X-NUCLEO-IKS01A1, and on the package it says it is compatible with Arduino Uno.
My goal here is to read data from any sensor on this board. (When I can ...
0
votes
3answers
34 views
I2C weird values when two slaves are connected parallel?
Alright I'm trying to connect two sparkfun ZX sensors that communicate to an Arduino Uno with I2C. When I connected each one independently to the Uno the Z and X values from the sensors seem fine. But ...
1
vote
0answers
31 views
Connecting arduino and EV3 using I2C
I'm trying to connect arduino uno and ev3 by using this guide (http://www.dexterindustries.com/howto/connecting-ev3-arduino/),
everything works perfectly but when i tried to use analogRead block to ...
0
votes
2answers
56 views
How to make Arduino to stop updating i2c data when meet a condition and wait until it receives another serial input from processing?
I am currently making a robot with Arduino Uno, D6T omron thermal sensor (i2c sensor) and some other sensors. My thermal sensor will always update the data in array form. It will display 4 data arrays ...
0
votes
1answer
15 views
PFC8574 4x4 keypad.. correct wiring?
I bought a few PFC8574 and 4x4 keypads for a small project. I'm unclear on the correct wiring of the keypad to the PFC8574.
On the Arduino Playground's site, there are pull-up resistors for each ...
1
vote
0answers
21 views
Why am I only receiving the first address byte? (I2C Protocol)
Expecting the slave to ACKnowledge and return data, but it does not. This is my protocol. This is my Datasheet.
Also FYI I'm on an Arduino Fio but I am not inheriting the Arduino library.
#include ...
0
votes
2answers
25 views
Resistor on SPI Chip Select Pin
I'm working on a modular CANBUS system for offroad racing. The idea right now is that the main Arduino (1284p at the moment) will be the only one connected to CANBUS, and other modules will have their ...
0
votes
2answers
26 views
I²C between 2 Arduinos sends additional receive event
I hooked up two Arduino Nanos with I²C, using 3 wires between GND <-> GND, A4 <-> A4, A5 <-> A5Ω and 1kΩ pull-up resistors on A4 & A5.
When I use the following code to communicate ...
7
votes
1answer
100 views
How to design and debug a custom I2C master-slave system?
How to proceed, when in need of a custom I2C master-slave system?
What are the design criteria to apply?
What are the debugging tools one can use to troubleshoot problems?
3
votes
2answers
106 views
SDA/SCL pins Arduino Uno
I am trying to figure if SDA and SCL pins from Arduino Uno is a TTL or a CMOS technology. I am not able to find this info anywhere but regarding it is a I2C protocol it does make sense to be a TTL ...
0
votes
2answers
68 views
I²C only works when I short-circuit my Arduino
I'm trying to connect an Arduino Nano with a Raspberry Pi 3 via I²C.
This is the small test-program I found and used for I²C.
#include <Arduino.h>
#include <Wire.h>
void setup() {
...
1
vote
0answers
36 views
Arduino Pro Mini I2C Problem
I am trying to connect a distance sensor VL6180x to Arduino Pro Mini via I2C. Yesterday it was working without any problems, but today it refuses to work, even though I haven't changed anything. The ...
2
votes
2answers
73 views
Wire Library send/receive
I'm doing a project which includes Arduino Uno and a Custom Hardware made by me. Everything is working perfect independently and I'm trying to implement a way for them to work together (the arduino ...
0
votes
0answers
8 views
Which backpack to use with NHD-0440WH lcd?
I would like to use the NHD-0440 (Newhaven 4x40 display) with Arduino over I2C/TWI. But I cannot find any suitable/available backpack. The above display is in reality made from two 40x2 displays, and ...
1
vote
1answer
21 views
How to operate under linux an USB to I2C adapter based on the FTDI FT232R?
How can I easily use, from the command line, the USB to I2C adapter based on FTDI FT232R?
0
votes
1answer
32 views
Arduino sketch won't run until I open up GUI in processing
I am trying to make a human detection robot using D6T omron thermal sensor. However, I am facing some problem here. My Arduino Uno didn't run the sketches until I open up my GUI in processing. The ...
1
vote
1answer
56 views
What does it mean in I2C, “NACK received”?
I am reading about I2C. On this site:
http://playground.arduino.cc/Main/WireLibraryDetailedReference#endTransmission
It says that endTransmission() can return one of the following status codes:
0: ...
0
votes
0answers
79 views
Gathering data from compass module (gy-271) with Arduino
I am trying to do a project using a Arduino mega 2560 and the compass module GY-271 (hmc5883L chip) , I've already imported the libraries (Adafruit_HMC5883_U.h, wire.h ,...) and i tried to use the ...
1
vote
1answer
76 views
Problem reading an EEPROM chip using I2C protocol
I am trying to read an EEPROM chip that supports the I2C protocol (cannot tell the IC model number as it is not printed). For sure it supports the I2C protocol, since I wrote a code to detect it using ...
0
votes
0answers
50 views
DS1803 Arduino I2C Wiring
I have hooked up the arduino mega to my DS1803 and have put 4.7K resisters as pull up resisters on the SCL and SDA line. When I use a scanner program (http://playground.arduino.cc/Main/I2cScanner) the ...
1
vote
0answers
77 views
How to read data from arduino with raspberry pi via I2C
I have connected Raspberry pi 2 model B with arduino uno via Bi-Directional Level shifter, from this BLOG
Raspberry pi GND ---------- GND Arduino
3.3v ---------- 5v
...
1
vote
2answers
53 views
How to write a sketch when adding more devices to a I2C data line
I am building a weather station that utilizes a battery operated outside unit that transmits data from a DHT22 sensor to a unit inside my house . The inside unit is using I2C communications from my ...
0
votes
3answers
66 views
Can someone explain how to program i2C communications without using the library?
I am starting to get into i2C, SPI, and other forms of communication. I have read about them and have a fuzzy idea of how they work electrically, but can someone explain how I would turn the ...
1
vote
1answer
19 views
Loop behaves oddly in I2C receiveEvent
I am messing around with an ATmega328P hooked on a Raspberry Pi, communicating over I2C: the ATmega is the slave (details at the end). While testing the basics of the concept, I faced an interesting ...
1
vote
1answer
63 views
Serial Not Working With I2C
I have been working on a hydroponic garden that is controlled with Arduinos. I have everything working except for the user interface. What I would like to do is have an LCD screen paired with a rotary ...
0
votes
1answer
41 views
Regarding using I2C with Arduino for Silicon Micro-structure 5852 D 1.5 psi
I am trying to get output from a sensor (micro-structure 5852D), but I only get two outputs: 11 and 255 for even applying pressure.
The following is my code, please show me how to over come this ...
2
votes
1answer
50 views
Send AND Receive through i2c / set Arduino as master AND slave
For a project I'm using 2 Arduino Uno's, where Arduino#1 (master) sends raw data to Arduino#2 (slave). The slave should receive and encrypt the data and afterwards send the encrypted data back to the ...
1
vote
0answers
27 views
Adafruit Trinket 3v with LED matrix backpack producing error
I have been wanting to create a Arduino watch. I built the circuit with an Adafruit Trinket 3v and an Adafruit LED matrix backpack (8*8). When I try to upload this example code:
...
1
vote
0answers
26 views
Reprogramming a specific slave from the master ATTiny 85 (connected to IDE)?
Given that every ATTiny connected already has a bootloader (micronucleus) installed, here's my theoretical chain:
Computer > Master ATTiny (Connected via USB) > ATTiny Slave A > ATTiny Slave B
Is it ...
0
votes
0answers
43 views
Connecting multiple Lidars to Arduino code
Currently, I am trying to connect a total of three Lidars to an Arduino Uno. Right now all I really have to go off is the diagram provided on the link below.
...
0
votes
1answer
29 views
i2c address instead of assigning pins
I found this sketch online and would like to reuse it. I do have a dot-matrix-display, that is accessable through an i2c with the address 0x70. How do I change the code to be able to use the hardware ...
0
votes
1answer
232 views
esp8266-01 and arduino UNO communicating over i2c
i am not able to communicate over i2c with my esp-01 as master and UNO as slave. i get special characters sent back to esp, but my esp is sending correctly...
output on my esp-01
output on my UNO is ...
0
votes
1answer
46 views
scroll text through multiple i2c connected dot matrix displays
I have 4 dot matrix displays, every one of them connected to an i2c and accessible with 0x70, 0x71, 0x72 and 0x73. All these work just fine when I address them apart. What I want to achieve is a ...
2
votes
1answer
36 views
Communication over I2C protocol with more than one A/D device
According to datasheet of MCP3021 A/D converter (Microchip, page 16) the MCP3021 can be accessed by proper address bits in control byte. In case of MCP3021 5AT the address is 101, in case of MCP3021 ...
2
votes
1answer
134 views
Multiple I2C Devices connected parallel
I have two Lidar Lites, connected to one APM. I have no issue with getting data from one of them, i use the code below
#include <I2C.h>
#define LIDARLite_ADDRESS 0x62 // Default ...
0
votes
2answers
289 views
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 ...
5
votes
2answers
263 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 ...
0
votes
1answer
19 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 ...
1
vote
0answers
123 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 ...
0
votes
1answer
62 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>
...
0
votes
0answers
38 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 ...
0
votes
1answer
134 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 ...
1
vote
1answer
107 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 ...
1
vote
0answers
50 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 ...
1
vote
0answers
140 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 ...
0
votes
1answer
86 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 > ...
1
vote
1answer
82 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 ...
