EVK-M8T User Guide
UBX-14041540 - R05
Device description
Page 8 of 22
Early Production Information
4.3.3
UART
The evaluation unit includes an RS232 port for serial communication that is compatible with PC
serial ports.
Connect using a straight RS232 serial cable with male and female connectors to the port on your
PC. The maximum cable length is < 3.0 meters. To configure the RS232 port, use the CFG-PRT
command in the u-center application. The maximum operating baud rate is 921.6 kBd.
If you are using a USB to RS232 adaptor cable, you can connect it directly to the evaluation kit RS232
port.
The 9-pin D-SUB female connector is assigned as listed in Table 4:
Pin Nr.
Assignment
1
Time-pulse 1 output (RS-232 levels)
2
TXD, GNSS Transmit Data, serial data to DTE
3
RXD, GNSS Receive Data, serial data from DTE
4
Optional time-mark input (RS-232 levels) using EXTINT0 (internal jumper J6 fitment required)
5
GND
6
Time-pulse 1 output (RS-232 levels)
7
Not connected
8, 9
not connected
Table 4: SUB-D9 Connector pin description for EVK-M8T
4.3.4
RST button
The RST button on the front panel resets the unit. To avoid an inadvertent reset, the button is
recessed.
4.3.5
Safe boot button
This is used to set the unit in safe boot mode. In this mode the receiver executes only the minimal
functionality, such as updating new firmware into the SQI flash. In order to set the receiver in safe
boot mode please follow these steps.
1.
Press the BOOT button and keep holding
2.
Press the RST button
3.
Release the RST button
4.
Release the BOOT button
5.
If the UART interface has to be used, the training sequence has to be sent to the receiver.
The training sequence is a transmission of 0x55 55 at the baud rate of 9600 Bd. Wait for at least
100 milliseconds before the interface is ready to accept commands.
4.3.6
Slide Switch
Use the slide switch on the front panel to choose between I2C (and UART) and SPI
communication
ports. You must reset the unit by pressing the RST button when the slide switch has been changed.
1.
I2C
– In this selection the EVK operates with the UART (RS232 DB9 – rear panel or the 3.3 V level
TxD (MISO), RxD (MOSI) at the front panel). Also the communication via 3.3 V DDC interface (I2C)
is selected.
2.
SPI
– In this selection the EVK operates only with the SPI interface. RS232 (DB9) is switched off.
