Led; Backup Battery - u-blox EVK-M8L User Manual

Pin no. Pin name
14 V5_IN
13 GND
12 P1A (VCC)
11 P1B
10 P2A
9 P2B
8 TIMEPULSE
7 WHEELTICK
6 FWD
5 SDA / CS
4 SCL / SCK
3 TxD / MISO
2 RxD / MOSI
1 GNDA
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.
UBX-20028627 - R01
C1-Public
I/O LEVEL Description
I 4.75 V - 5.25 V Power input – can be used instead of USB
Common ground pin for case-work, power and serial interface
I -
connections
O 3.3 V Power output – max. current supply 100 mA
1Ω 1% resistor for over-all current measurement to pin 11 (P1B)
NOTE: the current also includes LNA
O Second connection for overall current measurement
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).
O Second junction for battery backup current measurement
O 3.3 V Time pulse (internally buffered output)
I 3.3 V - 24 V Wheel tick input
I 3.3 V - 24 V Forward/reverse input for speed pulse
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
I/O 3.3 V Clock input / output
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)
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)
Isolated ground pin to be connected with wheel tick and
I -
Forward/Reverse signals
Device description
EVK-M8L User Guide
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