EVK-F9T - User guide
UBX-21040453 - R01
Device description
Page 10 of 23
C1- Public
☞
The RESET pin will delete all information and trigger a cold start. It should only be used as a
recovery option.
4.3.6
Safe boot button
This is used to set the unit in safe boot mode. In this mode the receiver executes only minimal
functionality, such as updating new firmware into the flash memory. To set the receiver in safe boot
mode:
1.
Press the BOOT button and keep holding it down.
2.
Press the RST button.
3.
Release the RST button.
4.
Release the BOOT button.
5.
If the UART interface is used, a training sequence must be sent to the receiver.
The training sequence is a transmission of 0x55 0x55 at a baud rate of 9600 baud. Wait for at
least 100 milliseconds before the interface is ready to accept commands.
4.3.7
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.
•
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.
•
SPI
–
In this selection the EVK operates only with the SPI interface. The RS232 (DB9) port is
switched off.
4.3.8
Pin header
This 14-pin test-connector provides additional functionality to the EVK, allowing access to the
interface pins and an ability to measure the current used by the ZED-F9T module. All pins are ESD
protected.
Pin no. Name
I/O Level
Description
14
V5_IN
I
4.75 - 5.25 V Power input
–
can be used instead of USB
13
GND
I
-
Common ground pin
12
CUR GPS1
O
5.0 V
Supply current measurement (Module current consumption) node 1. Current is
measured over a 1
Ω
1% tolerance resistor between pins 12 and 11. Pin 12
(CUR_GPS1) is at higher potential.
11
CUR GPS2
O
5.0 V
Supply current measurement (Module current consumption) node 2. See
description for pin 12.
10
NC
-
-
Reserved (the pin is reserved for floating, and the customer should not connect
any input to the pin)
9
EXTINT2
O
External interrupt 2 or time-mark 2 input (straight connected to the module
pins)
8
TIMEPULSE 1 O
3.3V
Output signal for the timepulse1 signal
7
EXTINT
I
3.3 V
External interrupt or time-mark input (connected directly to the module pins)
6
TIMEPULSE 2 O
3.3 V
Output signal for the timepulse2 signal
5
SDA / CS
I/O 3.3 V
If slide switch on I2C, the DDC interface is selected; Function: data input /
output
If slide switch on SPI, the SPI interface is selected; chip select input
–
LOW
ACTIVE
