how to read from i2c bus a rtcc PCF8523

[stefan.erni]

how to read the time from RTCC PCF8523 with i2c-bus (NXP8523)

I know the adress for reading (D1) and writing (D0) from the IC and I know the Register for seconds 0x04

But there is addrH and addrL
and some start and stop and acknowledge
hmm I need a litle help

bus_read.PNG

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[LeighM]

Ignoring any checks for Slave Ack/Nak, you would need the following:

Code: Select all

Initialise()
Start()
TransmitByte(0xD0)
TransmitByte(0x04)
Stop()
Start()
TransmitByte(0xD1)
data = ReceiveByte(1) // 1 = Last byte, no more requested
Stop()

[stefan.erni]

Hi Leigh

Sometimes life is easy...

Thank you for the help. This way it's working fine.