MCP7952X/MCP7951X SPI Real-Time Clock Calendar

[in_nursery]

Hi all

have someone already use this RTCC ?
is there any driver or source that exist for this ?

thanks in advance

[in_nursery]

hi all

So I begin to write the drivers for this RTTC.
I can write, read everything work good, but the data aren't stored and the clock seems not to run.
When I read my change, they are always the same no sec, min,.. change, just the value I store.
What I am doing wrong?

[ckielstra]

Posting a very short program (10 lines) would make it a lot easier to help you. Now we have to guess.

Do you make the CS line high again after the databyte has been written? So, the sequence to write to a register should be:
- make CS low
- send WRITE instruction (0x02)
- send address byte
- send data byte
- make CS high again
See figure 10-2 in the data sheet.

When you can read/write the registers but the clock is not running, then most likely you didn't set the ST bit in address 0x01. This bit is used to Start the Oscillator. See for further info the description of register 5-2 in the data sheet.

[in_nursery]

I find out my problem I erase the ST bit when I write the second.
So it's corrected.

[in_nursery]

another question
How to only set one bit on Spi Write command?

[ckielstra]

Using the 'logical or' command '|' you can add bits to an existing value.

[in_nursery]

Yes, I found it before your reply.
Everything work nice.
Thanks for your help.

[PrinceNai]