UM2032 Rev 3
17/40
UM2032
Hardware layout and configuration
39
5.3.5 Programming/debugging when the power supply
is not from ST-LINK/V2-1
Before connecting the USB cable from the ST-LINK/V2-1 USB
connector CN6 to the PC, it
is mandatory to power the Discovery kit using the user USB FS connector CN3 or the VIN
pin of the ARDUINO
®
Uno V3 connector CN2. Proceeding this way, ensures that the
enumeration succeeds thanks to the external power source.
The following power sequence procedure must be respected:
1. Put a jumper in JP3 at location USB to use power from the user USB CN3 or at location
E5V to use power from VIN of ARDUINO
®
Uno V3 connector CN2.
2. Connect the corresponding external power source.
3. Check that the green LED LD6 is turned ON
4. Connect the PC to the ST-LINK/V2-1 USB connector CN6
If this order is not respected, the Discovery kit may be powered by V
BUS
first from ST-
LINK/V2-1, and the following risks may be encountered:
1.
If more than 500 mA current is needed by the Discovery kit, the PC may be damaged
or current can be limited by PC. As a consequence the Discovery kit is not powered
correctly.
2. 500 mA is requested at the enumeration. If the PC cannot provide such current there is
a risk that the request is rejected and the enumeration does not succeed.
5.3.6
Measurement of current IDD drawn by the microcontroller
The jumper JP7 should be ON by default to supply the STM32F412ZGT6. To measure the
current IDD drawn by the microcontroller STM32F412ZGT6 only, remove the jumper JP7
and replace it by a multimeter (see
Table 4. Power-supply-related jumper settings
Jumper
Description
JP3
Default Setting
32F412GDISCOVERY is supplied through the
Micro-B ST-LINK/V2-1 connector
CN6. Jumper in STLK place.
32F412GDISCOVERY is supplied through CN3 Micro-AB USB FS connector.
Jumper in USB place.
USB
STLK
E5V
1
USB
STLK
E5V
1
