Hardware layout
UM1775
22/39
UM1775 Rev 4
•
Jumper in position ON: a module onboard is designed to measure from 100 nA to
50 mA by using several MOSFET and switching automatically depending on the read
value.
Figure 10. Jumper JP4 in position ON
•
NO Jumper on JP4: an ammeter must be connected to measure the STM32L053C8T6
current through pins 1 and 2 (if there is no ammeter, the STM32L053C8T6 is not
powered).
Figure 11. No Jumper on JP4
6.8 BOOT0
configuration
BOOT0 is at level “0” through a pull-down R65. To set BOOT0 at level “1”, use a
configuration with a jumper between P2.6 (BOOT0) and P2.5 (VDD).
Note:
To set BOOT0 at level "1" continuously, prefer to unsolder the resistor R65 to avoid a
consumption of 6 mA while connecting pin P2.6 (BOOT0) and P2.5 (VDD) with a jumper or
a wire.
6.9
Linear touch sensor / touchkeys
To demonstrate touch sensing capabilities, the STM32L053 Discovery board includes a
linear touch sensor, which can be used either as a three-position linear touch sensor or as
four touchkeys.
Three pairs of I/O ports are assigned to the linear touch sensor / touchkeys. Each pair must
belong to the same analog switch group:
•
PA2, PA3 (group 1)
•
PA6, PA7 (group 2)
•
PB0, PB1 (group 3)
