Other Parts Discussed in Thread: BQ25792, BQ25729
Hi
I'm not getting a reply from Chuck via email so I'm going to hope for some help via E2E here. I'm still struggling to get the I2Cr and I2Cw commands to work to read and write to and from the BQ25792 via the TPS25750
TPS25750 I2C address = 0x20
BQ25792 I2C address = 0x6B
This is what I do
1) Load the DATA1 register with the info I want to read
PD address | DATA1 register | #bytes | BQ address | BQ register | BQ #read bytes
eg:
I2C write : 0x20 | 0x09 | 0x03 | 0x6B | 0x3B | 0x02
2) Load the CMD1 register with "I2Cr"
PD address | CMD1 register | #bytes | 'I' | '2' | 'C' | 'r'
I2C write : 0x20 | 0x08 | 0x04 | 0x49 | 0x32 | 0x43 | 0x72
3) Then I check the CMD1 register
I2C read : 0x20 | 0x08 | 0x20
4) If I read the CMD1 register I get back:
0x04 | 0x49 | 0x32 | 0x43 | 0x72
Which is the same "I2Cr" 4CC command I sent it.
5) If I read back the DATA1 register I get back
0x40 | 0x6B | 0x03 | 0x02 | 0x00
This is the same data I put into it.
I don't think it's working as the I2Cm lines aren't toggling after step 2. Can you see what this all means and what I'm doing wrong?
It is a very complex process if you ask me and the documentation in the app note does not explain it well enough. Your document helps but there are errors there... for example, you didn't load the BQ I2C address into the data1 register and also you write "I2CR" instead of "I2Cr"
Can you help please! I'm stuck
Best regards
David
