Sim18 in I2C mode - help!!!

Hi,

I have a project using sim18 for gps tracking. I connect sim18 to stm32f10x via I2C mode. Can you help me answer questions:

1. using in I2C mode, how is package format to interface between sim18 and stm32f10x?
2. How to get NMEA messages?

thank everyone.

From SIM18 HD 1.02:

The slave has no way of forcing data to the master to indicate it is ready for transmission; the master must poll the client periodically. Since the specified idle byte pattern for both receive and transmit is A7 B4, the master can transmit this idle pattern to the slave repeatedly. If the master receives idle patterns back from the slave, it indicates that the slave currently has nothing to transmit but is ready to communicate. Default protocol is NMEA (protocol can be configured by NMEA $PSRF100 message).On the receiver side, the host is expected to transmit idle pattern A7 B4 when it is querying the module’s transmit buffer, unless it has traffic to send to the module. In this way, the volume of discarded bytes is kept nearly as low as in the UART implementation because the hardware does not place most idle pattern bytes in its RX FIFO.The FIFO thresholds are placed to detect large messages requiring interrupt-driven servicing. On the transmit side, the intent is to fill the FIFO only when it is disabled and empty. In this condition, the SPI driver software loads as many queued messages as it can to completely fit in the FIFO. Then the FIFO is enabled. The host is required to poll messages until idle pattern bytes are detected. At this point the FIFO is empty and disabled, allowing the SPI driver to again respond to an empty FIFO interrupt and load the FIFO with any messages in queue.

See page 20.