Ublox EVK-NORA-W101, Руководство пользователя

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EVK-NORA-W1 - User guide
UBX-22002764 - R02 Hardware description Page 14 of 22
C1-Public
If the signals GPIO15/ADC2-CH4 and GPIO16/ADC2-CH5 are used, the crystal can be removed from
the circuit by opening jumpers J19 and J21 and soldering across the normally open positions, as
shown in
Figure 12 . This connects XT-32k-p and XT-32k-n to the EVK pin socket J2, pin 5 and pin 6.
See also GPIO jumpers .
Figure 12: Schematic – 32 kHz crystal
3.8 Current sensing headers
The evaluation board provides two current sensing headers:
• J7 for power consumption measurement of the module VDD supply.
•
J8 for power consumption measurement of the module VDD-IO supply.
Each of the 2.54 mm pitch 3-pin headers has two pins connected across a 1
Ω
current-sense resistors
RMOD and RIO respectively, with the third connected to GND . The module VDD and VDD-IO supplies
are sourced through these resistors. To measure current consumption, use a multimeter or other
precise voltage measurement device to measure the voltage drop across pins 2 and 3. Current can
also be measured directly by opening
JRMOD or JRIO to remove the current-sense resistor from the
circuit. Use an ammeter in-series with the two voltage pins.
⚠
Pin 1 of J7 and J8 is connected to GND.
To bypass the current sense resistors, RMOD and RIO , solder the respective jumpers JMOD and JRIO .
The default hardware configuration does not require any modification of the current sense headers
for the EVK-NORA-W10 to perform properly.
Figure 13: Current sensing header circuits