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.
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Handling non-standard I2C read response lengths with Wire library
I'm trying to read from a Sam&Wing XW12A 12 channel touch sensor IC using I²C. The IC responds to an address read packet with 16 uninterrupted bits representing its state.
However, since I²C ...
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0
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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 ...
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3
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0
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190
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Using 2 VL53L4CD ToF sensors and getting error after getting first reading
pretty new to arduino stuff and was hoping to get some help with my code.
I'm trying to use 2 ToF sensors and get continuous readings from them. I understand that I have to use the xshut feature and ...
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3
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0
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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 ...
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3
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0
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517
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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 ...
- 143
3
votes
0
answers
687
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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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3
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0
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149
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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 ...
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2
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0
answers
471
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Scrambled Text on SSD1306 Using ESP32-S2
SSD1306 OLED display connected to an ESP32-S2 over hardware I2C. I noticed that the text will sometimes get scrambled or lag during a screen update. When left running long enough, the screen will get ...
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2
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0
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75
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MPU9250 and MPU6050 not working with SAMD21 board
I am trying to use an MPU6050 with my SAMD21-based board (a LightAPRS W-2), but it doesn't work.
The sensor definitely works, as I can get data from another 3.3 Vlogic-level board, and the sensor ...
2
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0
answers
187
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Wire library causing samd21 based board to stop working
A bit of a general question, but asking in case someone has stumbled onto a similar problem before. A friend and I designed a custom PCB board based on the ATSAMD21G microprocessor. The board has a ...
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2
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0
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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 ...
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2
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0
answers
660
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OLED display on I2C causes esp8266 to reset
I have connected two temp sensors and an OLED display to a NodeMCU using I2C. When the program reaches the instruction to print the measurements on the display the program crashes and NodeMCU resets ...
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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 , ...
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2
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0
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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 ...
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2
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0
answers
384
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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
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0
answers
256
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Using TCA9548A to read 30 ADCs
I want to read 30 differential ended analog sensors.
Using ADS1115 16 bit this is possible, but we end up having only 4 address on I2C, so i chose TCA9548A breakout board with 8 I2C multiplex channels,...
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2
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0
answers
860
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How to read the busy flag on LCD?
I have a standard 16x2 LCD screen and I have it hooked up to my Arduino UNO via a I2C backpack (4-bit mode).
Since I want to learn about the lcd at a lower level I’ve decided not to use the LCD ...
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2
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0
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637
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I2C on ATtiny85 and Si4703 radio
I've got an Si4703 breakout from Sparkfun, which communicates via I2C. I have gotten it to work very easily using a regular 3.3V Arduino Pro Mini, but am now trying to move everything over to an ...
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0
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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] = ...
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2
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0
answers
307
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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:
/*********************...
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2
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0
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150
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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 ...
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2
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0
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225
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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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2
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0
answers
815
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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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2
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0
answers
116
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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
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0
answers
191
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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 ...
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2
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0
answers
157
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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
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0
answers
429
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Receiving multiple bytes from an RPi using the i2c protocol
Trying to send bytes from an RPi as a master to an Arduino as a slave.
The send uses the write_byte(addr, value) function and seems to be working perfectly.
The Arduino however has issues with ...
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2
votes
0
answers
1k
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Unexpected Timer Conflicts (Uno)
I've been working on a project (Arduino Uno: Atmega328) that implements a gyroscope (which is used with the LSM9DS0 spark-fun library) that is communicated with through I2C and uses a Servo library. ...
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2
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0
answers
242
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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, ...
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2
votes
1
answer
203
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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 ...
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2
votes
1
answer
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Getting inverse values of acceleration and tilt for the MPU 6050
I'm using the I2C library to connect to a GY-521 board and, when executing the getAcceleration() methods I get gyro values and viceversa..
This is my setup (I'm using a proto shield but that shouldn'...
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1
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0
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38
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Weird issue with wire.requestfrom() and MailClient.sendMail() on ESP32- rst:0x3 (SW_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
Update_2: No change after Update_1, same error. I still have to comment either email, I2C, or Temperature out, that the other two can work.
Update_1: I'm also using a DS18B20 with #include <...
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1
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0
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329
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How to use multiple PN532 over i2c bus(es) and SPI?
I am working on a project that involves 3 PN532_modules to an ESP32, which sends the Tag_ID over BLE.
Plan A was to use One module on i2c_1, second on I2C_2 and third over SPI.
The SPI one works as ...
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1
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0
answers
830
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LiquidCrystal_I2C, lcd.begin() causes runtime error on Arduino Mega2560
I have tested the library and LCD with simple script and everything worked fine. Now I am trying to add the LCD functionality to my working program but the code reaches the lcd.begin(); function it ...
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1
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0
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190
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Pool pump man-in-the-middle SDA/SCL with ESP32
Hey all I have found some code on GitHub that works with my pool pump but it seems my model is a little newer than the one they used on on their GitHub. Most things seem to work but what doesn't is ...
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1
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0
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152
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LIS3DH not working with arduino
I am new to LIS3DH and tried to interface it with Arduino Uno. I have made the circuit as follows-
LIS3DH : Arduino Uno
SCL : SCL (GPIO18)
SDA : SDA (GPIO19)
3.3v : 3....
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1
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0
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225
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VL6180X returning to its default i2c address after shutdown
According to this thread the VL6180X after changing the i2c address the new address should persist after a power down. but when i changed mine it came back to its default address at 0x29. Here is the ...
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Arduino Wire library master reader, slave sender example not working
I tried i2c EPROM and that worked pretty fine with arduino master. then i wanted to establish i2c communication between 2 arduinos such that both exchange each other's sensors data. I am not able to ...
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1
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0
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56
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Help with the Arduino Wire I2C Communication with MAX16826 LED Controller IC
I'm trying to read and write to this MAX16826 LED controller evaluation board through I2C. There is no specific library for this IC so I have to use the Wire library and the datasheet to try to ...
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0
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71
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I2C and logic shifter troubleshooting
I'm attempting to use a SparkFun bidirectional level shifter (Link here) to connect up a 3.3v wii nunchuk to a 5v Arduino Uno circuit. For now all I'm trying to do is write the position of the ...
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0
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50
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Audio range with custom waveshape
I am planning to use several Arduino to produce audio range analog signals. I need to use custom waveshapes generated on the fly. As far as I understand, there are two paths:
Aquiring a DAC, but can ...
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0
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75
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Flight controller board Reprogram
Recently in my scrap yard visits, more and more I find cheap quad-copters and remote controllers of all kind. I have built up quite a collection of boards and spare parts to create my own army of ...
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0
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200
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Could not find AHT? Check wiring! How do i connect an AM2315C - Encased I2C Temperature/Humidity Sensor to a STM32F103C8T6?
am a little new at this so i sincirely need your help.
So I have a temperature & humidity sensor i got from http://www.aosong.com/en/products-70.html which is probably based on the AM2315C - ...
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1
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0
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940
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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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1
vote
0
answers
462
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Can a sensor have multiple I2C addresses?
So I'm having a weird issue with a TCA9548A multiplexer. When I run the scanning code given on the adafruit website, I get the following result:
TCAScanner ready!
TCA Port #0
TCA Port #1
TCA Port #2
...
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1
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0
answers
149
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I2C 16x2 LCD - Will Initialize (sometimes) - Holds Up The Code
Basically I have a keypad, that when a certain code is entered, it will write either "Wrong code" or "Good code" on the LCD.
At the same time a timer will count down until 0 is ...
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1
vote
0
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752
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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. ...
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1
vote
0
answers
218
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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....
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1
vote
0
answers
154
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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
1
vote
0
answers
562
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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 ...
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