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.

141 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
3
votes
0answers
931 views

How to use SPI to set/ read registers for a sensor (Avoiding need for Github Lib)

Ok so as some readers might have seen, my current project involves using MPU's. The idea is sending data via CAN bus to a controlling MCU to then send to a raspberry pi to perform the calculations ...
3
votes
0answers
451 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 ...
3
votes
1answer
58 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 &...
3
votes
0answers
131 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 Pi is the master and the Arduino is the slave). The Raspberry Pi generates random numbers and I want the slave (Arduino) to be ...
2
votes
2answers
43 views

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 ?
2
votes
0answers
61 views

SPI Arduino slave not recieving data correctly

Using an STM32L476RG Nucleo microcontroller board as the SPI master and an Arduino mega as a slave with pin 52 for SCLK, pin 53 for SS and pin 51 for MOSI on the Arduino. There is no issue with the ...
2
votes
0answers
159 views

qMenuSystem using DigoleSerial library doesn’t work on my I2C Monochrome OLED

Just like the title says I’m trying to make qMenuSystem to work with my oled display. Here is what I know so far about my display : - It's a Monochrome OLED 128x64 (Blue) Display - It's connecting ...
2
votes
0answers
116 views

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 ...
2
votes
0answers
169 views

STM32F103C8 - Arduino Mega FAST MODE(400000L) I2C communcation not working

I'm trying to connect a stm32F103C8 board (master) to an Arduino Mega (slave) over I2C. I have a master and slave program which runs perfectly fine when the clock frequency for I2C communication is ...
2
votes
0answers
5k views

Why is Wire.onReceive() called during requests?

I'm building a complex I2C-based networking protocol and have noticed that the Wire.onReceive() handler is called both for I2C read and write operations. When the master writes to the slave, it is ...
2
votes
0answers
2k 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] = ...
2
votes
0answers
280 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: /*********************...
2
votes
0answers
145 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 ...
2
votes
0answers
194 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 ...
2
votes
0answers
618 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 ...
2
votes
0answers
720 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 ...
2
votes
0answers
108 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 ...
2
votes
0answers
775 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 ...
2
votes
0answers
144 views

Basic communication between Cotek and Arduino UNO

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 ...
2
votes
0answers
145 views

I2C with an arduino, a PI and an IO expander

im working on a project which requires alo i/o pins. For that reason i bought a pcf8574P 8bit I/O expander which uses the I2C protocol. The problem is how to combine the Rasp PI and the arduino. For ...
2
votes
1answer
1k views

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 ...
2
votes
0answers
219 views

GPS - Speed doesn't update as should - EM408 & Arduino Mega & GSM

I'm developing a system that will get the GPS signal and send it though the GSM with information about position, speed and temperature from some digital sensors. Currently I'm using the GPS EM408, ...
1
vote
0answers
53 views

ESP32 + Attiny85 AC Dimmer

I am working on an AC Dimmer project using ESP32 and Attiny85. Note : I know ATtiny85 is overkill for this project, And it can be done without Attiny85, I have already done this using ESP32 alone. ...
1
vote
0answers
30 views

How to name the temperature sensors instead of printing address using ds2482-100 and ds18b20 sensor- Help

I am using 10 ds18b20 Temperature sensors using with "DS2482-100" I2C board and Arduino so when I am getting the output like this:- "ROM = 28 46 04 1F 0D 00 00 74 96014B467FFF0A100A 25....
1
vote
0answers
38 views

Unable to write, or read a sensor's registers. Do I have an error in my code?

I'm trying to write to register the change some settings for a sensor I'm using (BNO055) and then read the same register to verify if the changes are successful. However, the only value I'm able to ...
1
vote
0answers
58 views

Prevent flicker - Lcd with I2C module?

I have a 16x2 LCD with a I2C interface, and a Esp8266 based NodeMCU. I Have an issue where the second line of the LCD is flickering, but somehow the first line does not flicker. Why does this happen ...
1
vote
0answers
44 views

How to use pins for I2C that is used from other hardware?

I am using ESP32 CAM for one project and I have a sensor that is I2C connected to pins 21 and 22 (default I2C). The sensor is working fine until I turn on the camera. The camera uses this pins (21,22) ...
1
vote
0answers
58 views

Arduino Uno I2C two sensor connection Issues

I have been working on trying to get the MAXREFDES#117 PPG and the LIS3DH Accelerometer to run together. I am modifying the sample code found here to do so: https://github.com/...
1
vote
0answers
45 views

How to get a stable LED lighting without scintillation over I2C bus

I built an 8x8 led matrix using white 5mm LEDs. I drive the LEDs using the MCP23017 connected to an Arduino over the I2C bus. The wiring of the LEDs in the matrix is such that a row is made up of 8 ...
1
vote
0answers
71 views

Using MPU6050 with ESP32 Cam- MPU Not Detected

Hi I'm trying to build a self balancing robot using my esp32 cam, but so far I haven't been able to setup my mpu6050 with it.I'm using the adafruit libraries with the given example sketches. The only ...
1
vote
0answers
32 views

send command to Slave and receive response over I2c

so I have an Arduino mega as the master and an attiny84 as the slave the master can send a command S to the slave and the slave should respond with TRUE so here is my code: master: bool GetOnline(){ ...
1
vote
0answers
104 views

Reusing Digispark ATtiny85 micro-USB as 1-wire bus

I'm working on a project of my home plants irrigation/hydroponic system(not cannabis!)) just chilies and other eatables). Also I'm trying to recycle modules, wires and other projects' leftovers such ...
1
vote
1answer
38 views

Having trouble with MPU6050 and AFE4404 printing together, potential conflict?

I am having trouble getting the two sensors to work together. There are a total of four sensors connected to the Arduino, and while the MPU and AFE individually work fine with the other two sensors, ...
1
vote
0answers
140 views

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 ...
1
vote
0answers
23 views

Help Convincing Wiimote a Nano is a WiiMotion Plus

I want to replace the outdated gyro in a wiimotion plus with a BNO055. Based off what I've read from wiibrew, and im currently trying to get the wiimote to recognize the nano as an extension over I2C. ...
1
vote
0answers
31 views

How to know if a tof VL53L0x sensor is dead or not

I bought a bunch of VL530X time-of-flight sensors on Aliexpress. They seemed to work fine. Then I connected two of them on the same Arduino Uno board to test with the Adafruit example "dual"....
1
vote
0answers
78 views

Use I2C to control one of three DS3502 Adafruit digital potentiometers on the same I2C bus

My teammate and I recently purchased a handful of DS3502 digital potentiometers (https://learn.adafruit.com/ds3502-i2c-potentiometer/pinouts) from Adafruit, and we'd like to be able to control them ...
1
vote
0answers
91 views

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 ...
1
vote
0answers
97 views

Configure Trinket M0 as I2C peripheral

I am trying to use I2C to communicate between my XBee3 (controller) and an adafruit trinket m0 (peripheral). I'm pretty confident I have the modules connected properly (trinket SCL/pin 2 to xbee SCL/...
1
vote
0answers
155 views

Arduino Nano Every Vin 5V fixes I2c problems

I had problems with connecting my devices via I2C. The "requestfrom" constantly hanged and the endtransmission sometimes gave NACK responses. After disconnecting the devices from 12V and ...
1
vote
0answers
132 views

Max. external ADC speed with ESP32 (SPI or I2C)?

What is the maximum speed for external ADC I can expect to get with ESP32? I'm planning to have 16-bit ADC connected to I2C or SPI whichever gives more speed. How that information is calculated from ...
1
vote
0answers
51 views

Looking to interface height and weight sensor based on I2C Protocol

I have interfaced a height sensor and a weight sensor. The I2C address of the height and weight sensors are 0x29 and 0x2A respectively. I have merged the example of both the sensors. This is the first ...
1
vote
0answers
64 views

Arduino Create and Raspi I2C

I'm trying to communicate via I2C on the Raspi, programming it with the Arduino Create Web Editor. I have enabled I2C on the pi, made sure /dev/i2c-1 exists. The pi can see the device (just a simple ...
1
vote
0answers
47 views

Getting the I2C Address from a Max9744 amplifier

I just bought 2 Max9744 amplifiers that I wish to scan the I2C addresses, just to check against what is said in documentation. I have the amplifier powered with a 12 v supply and the Arduino powered ...
1
vote
0answers
78 views

leonardo mouse readings

hi there im using arduino uno + usb host shield and i have taken the readings from the usb mouse in this line of code : x = mi->dX; and the x output is the speed of the mouse x coordinates and i ...
1
vote
0answers
286 views

Connecting OV2640 with 17 Pins Binocular Camera module, to any microcontroller (System clock on module pin 18 -NC)

These pins are on the module: 3.3V GND VSYNC SCL SDA HREF D0-D7 DCLK PWDN I have tried many codes and connections of the OV7670 Monocular cameras, none seem to work(Instructables , Circuit Digest , ...
1
vote
0answers
215 views

I2C master's output is always 255

we are using 2 Arduino UNO as a master/slave for this i2c protocol. we used the first Arduino(slave) as a sensor that will input dummy data (in this case, temperature data). the Arduino(master) should ...
1
vote
0answers
36 views

Does DFR0063 I2C LCD work with Arduino Due? I cannot even pass i2C scanner

I have 2 Due and Two DFR0063 I2C LCD. I cannot even pass i2C scanner. I always got No I2C devices found. I tried both SCL/SDA and SCL1/SDA1. For SCL1/SDA1, I do add 10K pull up resister. But still ...
1
vote
0answers
57 views

Slave unreliably sends bit 7

I'm trying to send a byte from an Arduino Nano I2C slave to a Raspberry Pi 3B Master by directly connecting the two I2C pins of each device with no external pull-ups or level converters. It mostly ...
1
vote
0answers
114 views

Configuring the registers of i2c AD converter ADS122C04

I am not able to set the configuration registers of the TI´s converter chip ADS122C04 using arduino MEGA via I2C. The code mainly consists of the following: 1-reset the chip (one byte) 2-choose ...