Hi all,
New here. Just started experimenting with the DS1307. I honestly overlooked the voltage requirement and didn't realize that it was a 5V device, however I modified my circuit to run it on 5V.
In the electrical specs under RECOMMENDED DC OPERATING CONDITIONS, it states that Logic 1 Input VIH is minimum 2.2V...
Although this IC is running on 5V, I have SDA and SCL tied to a 2.4K pull-up to 3.5V to my MCU.
On this same I2C bus, I have an MPL3115A2 altimeter and it works and responds.
The problem is the DS1307 doesn't appear to be responding. I send it an I2C read to device address 0x68, register 0x00 and it returns 0xFF.
In fact, a read to any register will return 0xFF.
Then if I do a subsequent read to the altimeter's address, it returns what I expect.
Any ideas or pointers is appreciated.
Below are two screenshots:
MPL3115A2 (works):
DS1307 (not working):
Thanks!
Ben