5.4
Boot mode
To enter the boot mode of the STM32L476RG microcontroller press and hold the Boot button(1) then press the
RESET button(2). At this point the boot mode is active and both buttons can be released.
Figure 8.
Entering the boot mode
5.5
Power supply
The ST25RU3993-EVAL is supplied by the USB 3.0 port of the host PC. An USB 3.0 port is required if the long
range configuration using the external PA is set.
If an USB 3.0 port is not available an USB 2.0 Y-cable or an external power supply can be used to enable the long
range capabilities of reader.
If neither is available only the short range reader configuration with lower RF power is available. If the
ST25RU3993-EVAL board is configured as short range reader using the internal PA an USB 2.0 port would
suffice.
In order to observe and measure the current consumption of the entire reader a 2-pin header is available. In
normal operation this 2-pin header is shorted by an jumper. To measure the current consumption remove the
jumper and connect an ampere meter in series instead.
To connect an external 5 V supply see
.
UM2353
Boot mode
UM2353
-
Rev 2
page 15/48
Содержание ST25RU3993-EVAL
Страница 25: ...Figure 16 Schematic of UHF RFID reader device UM2353 Rev 2 page 25 48 UM2353...
Страница 26: ...Figure 17 Schematic of external power amplifier UM2353 Rev 2 page 26 48 UM2353...
Страница 28: ...Figure 20 Schematic of USB supply UART bridge UM2353 Rev 2 page 28 48 UM2353...
Страница 29: ...Figure 21 Schematic of microcontroller UM2353 Rev 2 page 29 48 UM2353...
Страница 30: ...Figure 22 Schematic of supply LDOs UM2353 Rev 2 page 30 48 UM2353...
Страница 31: ...Figure 23 Schematic of external interfaces and connections UM2353 Rev 2 page 31 48 UM2353...
Страница 32: ...Figure 24 Schematic of BT classic module UM2353 Rev 2 page 32 48 UM2353...
Страница 33: ...Figure 25 Schematic of RF shield UM2353 Rev 2 page 33 48 UM2353...
Страница 39: ...8 4 GND layer Figure 30 Layout GND layer UM2353 GND layer UM2353 Rev 2 page 39 48...