Hardware setup
UM0882
Doc ID 16881 Rev 2
3 Hardware
setup
The main board components are shown on
Figure 2.
Setup of the board
3.1 Power
supply
The board is powered by a 7.5 to 18 V DC voltage. The power source must be able to deliver
a 0.7 A current. Since the board has a built-in diode bridge, the polarity of the input voltage
is not specified.
3.2 Microcontroller
JTAG
The board is equipped with a standard 20-pin JTAG connector allowing to debug and
develop the STM32 microcontroller.
3.3
Microcontroller clock, reset, USB clock
The STM32 on-board microcontroller uses its internal RC oscillator to generate an 8 MHz
clock (that is converted to 48 MHz by a PLL). The clock is also used to drive USB. Since the
internal RC oscillator does not allow to achieve the clock stability defined in USB
specifications, it is recommended not to use the internal RC oscillator in conjunction with the
USB interface. The USB is used only for demonstration purpose, but the performance is
limited due to this internal RC oscillator stability.
3.4
Jumpers for LED failure simulation
LED defects can be simulated by using P20, P21 and P22 jumpers:
●
Removing a jumper on P20, P21 and P22 causes D1, D2 and D3 green LED open-
circuit
●
Placing a jumper on P1, P2, and P3 causes D6, D9 and D12 blue LED short-circuit.
These simulated defects can be detected during the activation of the error detection
mode (see
). The defective LED is highlighted by switching on the
corresponding red LED.
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