EVK-M8L User Guide
UBX-20028627 - R01
Device description
Page 10 of 33
C1-Public
Pin no. Pin name
I/O LEVEL
Description
14
V5_IN
I
4.75 V - 5.25 V Power input – can be used instead of USB
13
GND
I
-
Common ground pin for case-work, power and serial interface
connections
12
P1A (VCC)
O
3.3 V
Power output – max. current supply 100 mA
1
Ω
1% resistor for over-all current measurement to pin 11 (P1B)
NOTE: the current also includes LNA
11
P1B
O
Second connection for overall current measurement
10
P2A
O
3.0 V
Battery output (unloaded)
100
Ω
1% resistor for battery backup current measurement to pin 9
(P2B)
NOTE: There is a current protection to 3 mA. See the circuit in Figure
16 (D2, D4, R29).
9
P2B
O
Second junction for battery backup current measurement
8
TIMEPULSE
O 3.3 V
Time pulse (internally buffered output)
7
WHEELTICK
I
3.3 V - 24 V
Wheel tick input
6
FWD
I
3.3 V - 24 V
Forward/reverse input for speed pulse
5
SDA / CS
I/O 3.3 V
If the slide switch is on I2C, the DDC interface is selected; Function:
data input / output
If the slide switch is on SPI, the SPI interface is selected; chip select
input – LOW ACTIVE
4
SCL / SCK
I/O 3.3 V
Clock input / output
3
TxD / MISO
I/O 3.3 V
If the slide switch is on I2C, the DDC interface is selected / UART TxD
(3.3 V level)
If the slide switch is on SPI, the SPI interface is selected; Master in,
Slave out (MISO)
2
RxD / MOSI
I/O 3.3 V
If the slide switch is on I2C, the DDC interface is selected / UART RxD
(3.3 V level)
If the slide switch is on SPI, the SPI interface is selected; Master out,
Slave in (MOSI)
1
GNDA
I
-
Isolated ground pin to be connected with wheel tick and
Forward/Reverse signals
Table 4: Connector pin descriptions for EVK-M8L (pins numbered from right to left on the front panel)
⚠
THE EVK CASE-WORK IS CONNECTED TO THE COMMON SUPPLY/INTERFACE GROUND PIN.
Contact u-blox technical support for assistance if required.
3.3.8
LED
On the front panel of the unit, a single blue LED may be configured to follow the receiver time pulse
signal using the UBX-CFG-TP5 message. The time pulse may be configured so that the LED starts
flashing at one pulse per second during a valid GNSS fix. If there is no GNSS fix, the LED will only light
up, without flashing. The time pulse is enabled by default in the EVK-M8L.
3.3.9
Backup battery
The evaluation unit includes a backup battery. This is necessary to store calibration and navigation
information between operations and to enable immediate startup in DR mode, and fast acquisition
of GNSS signals.
