PCF8563 RTC I2C not working with Arduino

Using Arduino Networking, Protocols, and Devices
1

I have an RTC circuit with an Arduino UNO using a PCF8563 breakout (https://www.amazon.ca/PCF8563-PCF8563T-Clock-Module Arduino/dp/B01DB8JECC). I've tried several libraries and all of them have the same problem that connecting does not work. Using the I2C scanner does not show it:

Scanning...
No I2C devices found

My circuit is:

Arduino Breakout
5V VCC
GND GND
SDA SDA
SCL SCL
I have also tried using the A4/A5 pins and that did not work either. I have tried with a 10k pull-up resistor (from SDA -> VCC and SCL -> VCC) and without.
2

If this schematic matches your module, then there are already quite strong (1k) pullup resistors on SDA and SCL https://www.waveshare.com/w/upload/b/be/PCF8563-Schematic.pdf (just something to consider if you add more I2C devices to the same bus).
What Arduino board are you using ?

3

What Arduino board are you using ?

An Arduino UNO R3:

actual
actual417×527 347 KB

4

Do you have the battery installed? Some boards do not function without the battery, even if connected to VCC.

5

I do have the battery installed.

6

Then your wiring or breadboard or module must be faulty. What does your setup look like?

7

setupp
setupp1920×1108 160 KB

I also tried putting the SDA/SCL directly to the SDA/SCL pins

8

I cant really be sure from the photo, but is the RTC actually soldered to the header pins, or just sitting on them?

9

It is not yet soldered to the header pins, could that be the problem?

10

Yes!

Don't feel too bad, as you're not the first poster to have done this, so I knew to look closely at the joints. :wink:

1 Like
11

Thank you, that worked!

12

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