Which pins should I use for I2C on Arduino Uno - Stack Overflow
I am trying to create an I2C communication bus with an Arduino UNO. I2C requires SDA and SCL pins. I see on Arduino UNO there are 2 SDAs and SCLs: The 2 first two pins side to the USB connector are...
Help troubleshooting I2C - Arduino Forum
Jul 20, 2025 · On Uno R3, A4 & A5 are the i2c pins because Uno has an ATmega328 chip, and on that chip, they are dual function. They can be used as either A4 & A5 analog inputs, or they can be used …
UNO R4 WiFi I2C Pins - Arduino Forum
May 22, 2025 · I am reasonably familiar with Arduino boards and I2C pins but I found the explanation in the UNO R4 WiFi documentation a bit confusing. The documentation says: The UNO R4 WiFi has …
Internal pull up resistor in i2c, Arduino uno
Apr 6, 2022 · When configuring the Arduino uno digital pins to work as i2c pins, are they automatically configured to use internal pull up pins? Internal pull-ups are only active when the IO lines are …
I2C change pins, Arduino uno R4 wifi
May 26, 2025 · Dear forum. According to different posts it might be possible changing SDA/SCL pins for I2C bus on Arduino uno R4 wifi ? At first trials I2C slave works perfect via standard D18/D19 pins. …
Wire.begin parameters for a client - Arduino Forum
Jul 28, 2022 · I want set up an arduino board as an I2C client with wire.begin(stationNumber) I also want to change the pins to non standard using E.g. wire.begin(D3,D4) will wire.begin() accept 3 …
I2C with internal pullups - Arduino Forum
Dec 31, 2015 · Internal pullup is between 30k-60k on RESET pin and 20k-50k on all other I/O pins, according 328P's datasheet. It is far higher than I2C requirement is. I tested I2C with the internal …
UNO R4 WiFi 3rd I2C Bus? - Arduino Forum
Jul 3, 2023 · Arduino creates "Wire" and "Wire1" as soon as the Wire library is used in the sketch. They are fixed to certain pins. That makes the sketch easier for beginners, but in my opinion the object for …
arduino uno - How to connect an lcd i2c using only pins A0 and A1 …
Dec 28, 2020 · The note // Wiring: SDA pin is connected to A4 and SCL pin to A5. is referring to the analog pins of an UNO (or Nano) because these pins also happen to carry the ATMega328P's I2C …
Using SDA & SCL pin or A4 & A5 pin? - Arduino Forum
Oct 24, 2023 · On the Arduino Uno board there are SDA pins and SCL pins. If I have used the SDA and SCL pins for a 16x2 LCD, can the A4 and A5 pins be used for other sensors?