Questions tagged [wire-library]
Use this tag for the Wire library, used for I2C/TWI communication.
101
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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"
...
- 366
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3
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Arduino Wire.h library: how to communicate with an LCD?
I am having an Arduino Uno and a 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 &...
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1
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Arduino Uno Wire Transmission Issues
I am developing code to run a word clock and have noticed a slight problem. I am using a DS3231 to keep time, and using the Wire library to communicate with it. I ping the DS3231 every second to get ...
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458
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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 (https://github.com/...
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2
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657
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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 ...
- 171
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1
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769
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I2C hookup - sketch just crashes
I am encountering problems with I2C when trying to attach a 9DoF Sensor to my Arduino Uno. Following these instructions (the hardware setup I have is like in the schematic) I noticed the basic example ...
- 173
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0
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42
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slave arduino receiving commands from two serials
I have a slave arduino connected to a master arduino mega (through UART) and to a RPi (through USB). The slave arduino is set to monitor various SHT85 (through I2C) and NTC sensors. What I would like ...
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0
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40
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Problem when using Servo.h and WIre.h libraries [duplicate]
I have a project that consists of an Arduino, a NodeMCU and 2 servos. The NodeMCU is configured as master and the Arduino as slave. I have bidirectional flow of data between them.
In order to receive ...
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0
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803
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I2C / TWI: set up atmega328p as slave
I try to run an atmega328p as a i2c slave. even with the bare minimum the slave acts as its not wired at all: NACK is transmitted after request (see logic analyzer).
The master should read a constant ...
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0
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145
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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 ...
- 367
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0
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219
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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 ...
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1
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0
answers
224
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Servo PWM Pin seems to be interfering with Wire.onRequest i2C function
A newbie here. I am thinking of interfacing Raspberry Pi with Arduino via I2c to control a few servo motor (as RPi have limited PWM pins). Meaning I would send input from RPi to Arduino to allow to ...
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0
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Wire doesn't work between Uno & ESP32S & ESP8266
I think i've reached my limit. I can't get Wire to work between an Uno or ESP8266 or ESP32S. On the Uno I had them connected like SDA via Uno SDA -> ESP32 GPIO21 SCL via Uno SCL -> ESP32 GPIO22.
I ...
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0
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178
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Multiple Atmega328p wired communication
I am using multiple ATMEGA328Ps (4 ATMEGA328P) (OR Arduino Unos). The distance between two farthest ATMEGAs is 14 meters (One is Master Device and Other is Node), and other 3 are connected to each ...
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1
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750
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Communicating with I2C DAC (LTC2631)
Firstly, let me say that I'm new to using I2C devices, especially with Arduino. I have an 8-bit DAC (LTC2631) that I'm trying to control with an Arduino Uno. I thought I would be able to use the ...
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2
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909
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ESP8266 not working with MPU 6050 over wire library and I2C
I'm trying to use this version of ESP8266 to access MPU 6050. However, it's not working.
https://www.amazon.com/gp/product/B07HF44GBT/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1 i.e. ...
0
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2
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112
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Questions about HMC5883L library
I'm studying the structures of libraries currently. I want to learn how good programmers write code, what are the strategies they follow, the art the programmer followed to develop the library. And ...
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1
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646
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TWI Wire.setClock() on non arduino AVR MCU issue
Using an Atmega168P - programmed by means of avrdude with the .hex file generated by Arduino IDE.
The following code sets the 8 MHz Atmega's TWI interface to just 15.625 kHz:
Wire.begin(); // ...
- 127
0
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1
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77
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Erratic behaviour using a DUE with the Microchip 24FC64 EEPROM chip?
I am attempting to read and write from/to an EEPROM chip, and have got access to this 64 kbit device.
It appears I can write to the device and read from it, but there appears to be some strangeness ...
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2
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1k
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Cannot display a chr string using Wire.read() and u8g2.drawStr()
I'm still getting myself acquainted with C++, so I expect this is a very basic issue I'm facing. I've got an OLED screen connected to a Teensy LC and can display text on it just fine. The Teensy ...
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2
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I2C call during Wire.requestFrom
Which I2C command happen during Wire.requestFrom(address, quantity)?
Is it correct that Wire put a Start condition, then 7-bit address appended with read bit? How would that be different from Wire....
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0
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1
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448
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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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1
answer
1k
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Sending more than BUFFER_LENGTH(32) bytes in slave answer I2C
I need to send 259 bytes as answer to I2C master read request. AFAIK there is a buffer limit of 32 bytes in Wire.h and in HW (Arduino Nano). Is there a way sending 259 byte answer, or I have to choose ...
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0
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1
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862
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I2C Wire.onRequest not detected
I want to know why Wire.onRequest can not detect below massage and what I can do to detect it.(I am not able to change I2C massage)
I was able to read this part of the massage with wire.onReceive:
...
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0
votes
2
answers
275
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Sharing serial output from one to many arduinos (plus a computer) via USB hub
I am trying to send rotary encoder output from an UNO to seven Trinket M0s and a computer via a (powered) USB hub.
Currently the UNO → Laptop bit works great, serial monitoring works via the hub ...
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0
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1
answer
3k
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Issues with I2C and Wire.Available()
I am working on a project which requires communication from an Arduino Due (Master) and an FDC2214Q1 C to D IC (Slave), but there is some variability as to whether the code works or not depending on ...
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1
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938
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Why does my 16x2 LCD displays weird letters and can't insert key from keypad?
I'm a newbie on Arduino here, and this is my first project on 16x2 LCD, 4x4 keypad and others. So, the story is, after I uploaded the program for my group's Arduino alarm clock to the Arduino board, ...
0
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1
answer
201
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Not clear code procedure in Arduino wire library
The application code of sparkFun, has the following line which is difficult to understand.
It's requested 6, because it's requesting 6 bytes for HMC5883L module.
Wire.requestFrom(address, 6);
if(6&...
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0
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1
answer
819
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Reconnect to I2C with a different address (ATTiny85)
My project requires to reconnect to an I2C bus as a slave. I can't reset my ATTiny physically because I2C + my project + a pin to trigger the reset isn't possible due to the limited amount of pins ...
0
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1
answer
173
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Different questions regarding Arduino C++ library coding style
I'm reading the two wire library in Arduino libraries and in the C++ source code I found different methods which I don't know what they mean, in the following:
// Initialize Class Variables /////////...
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1
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1k
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I2C MCP4725 DAC connection speed
I'm trying to use the MCP4725 DAC from Adafruit (https://www.adafruit.com/product/935) to output some waveforms over a frequency range up to about 50kHz. At the moment, I'm simply sending values to ...
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0
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1
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499
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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 ...
- 103
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2
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1k
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I2C communication between 2 Arduinos with updated wire library
I would like to enable communication between two Arduino 101. From what I have read, the best method is to use I2C using the wire library. However, it seems as though the newest Arduino IDE has an ...
- 101
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1
answer
297
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Olimexino 32u4: 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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1
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442
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pcDuino 3B Wire library errors
I recently purchased a pcDuino 3B and I am very pleased with the Board so far. I can use the preinstalled arduino IDE to program the board from the board and run programs.
However, when I came to use ...
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1
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1k
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Compilation error when trying to give pointer to a function to another function
I'm trying to write a library for Arduino using the Wire library.
Here's my code:
PiCom.h:
#ifndef PiCom_h
#define PiCom_h
#include "Arduino.h"
#include <Wire.h>
class PiCom
{
public:
...
- 103
0
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0
answers
58
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Compilation error with MMA8451 accelerometer and attiny85 using ATTinyCore
I am trying to use the Adafruit MMA8451 accelerometer with an attiny85. The Adafruit library uses Wire which doesn't work on the attiny so I used the ATTinyCore board files which have been modified to ...
0
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1
answer
603
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Wire Library Timer Usage
I would like to know if the Wire Library is using a Hardware Timer from the Arduino Mega 2560. And If so which Timer it is.
As I am using the Timer 1. After implementing the Wire Library I have some ...
0
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1
answer
193
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Compass heading not varying linearly
I am using an HMC-5983 magnetometer compass on my arduino uno to find the heading of a car I'm building.But my compass readings aren't varying linearly.For example when I physically turn my compass by ...
- 219
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1
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341
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Same output on displays with different I2C-addresses (AdaFruit library, ESP32)
I've got two displays hooked up to a ESP32 via I2C and I'm using the AdaFruit library. All handling display output is packed in a own library. As I was testing I only had one display set up and ...
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1
answer
2k
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Wire library compatibility Arduino Pro Mini - nodeMCU (I2C/TWI) problem
I'm writing PortExtender, a library to convert an Arduino Pro Mini in a port expander and I ran into what seems to be a compatibility problem between Arduino and nodeMCU: I got different answers ...
user31481
0
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2
answers
1k
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Tiny RTC I2C module not working
I bought a Tiny RTC I2C module and it doesn't work.
When i run the TimeRTCSet from TIME library all i get is:
Unable to sync with the RTC
0:00:00 0 0 1970
0:00:01 1 1 1970
0:00:02 1 1 1970
0:00:03 1 ...
0
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1
answer
821
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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
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2
answers
4k
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SPISettings was not declared in this scope
I'm trying to compile a simple I2C example to read data from an MPU-6050 accel/gyro sensor, but I'm getting the compilation error:
/usr/share/arduino/libraries/SD/src/utility/Sd2Card.cpp:27:8: error: ...
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0
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1
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440
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Using a class instance with Wire.onReceive
Is it possible to register a class instance member function with Arduino's Wire.OnReceive?
I'm trying to make my code object-oriented, and want a specific non-static class function to handle I2C data,...
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-1
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1
answer
221
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MAX9611/2 - receiving junk data
I'm connecting to a MAX9611 on a custom PCB (using a SAMD Cortex M0 running an Adafruit Feather bootloader) using I2C. I have code that reads the voltage, current and temperature from the internal ...
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1
answer
2k
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Reading values from TTP229 capacitive touch sensor on arduino
I would like to be able to read the raw capacitive sensor values from a TTP229 chip through i2c in Arduino. I have one of these breakout boards to play with :
My goal is to get values similar to ...
- 161
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1
answer
1k
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i2c Connection for MCP4725(Dac) with Esp8266 wemos d1 mini
------------ This question has been edited ------------
note: Dac and Adc is12bits
my problem : I use two ESP. Using esp1, I read the Adc amount of the alternating signal (ECG) and send it to esp2 ...
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votes
1
answer
96
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Sketch starts and keeps counting on external power supply but not usb
Thank you for the add, total newbie here (electronics and arduino) on his first project.
Trying to make a counter for a hay baler with two HAL effect sensors, (pin 5 & 6) and outputting to an I2C ...
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1
answer
2k
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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 ...
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