Important changes to forums and questions
All forums and questions are now archived. To start a new conversation or read the latest updates go to forums.mbed.com.
11 years ago.
What do you mean by "wedge" ?
What is a wedge circuit? nR (pin 4) has a pullup resistor. Pin 5 is configured to activate the sw_reset. And the "wedge" is a diode pointing to pin 5 ?
Question relating to:
2 Answers
11 years ago.
This is the 'technical' term for the 'K' cathode of the diode
yes I know K for cathode ..
:)
Ceri
11 years ago.
Never heard the term 'wedge circuit' before, but what happens is that, thanks to the diode, pin 5 can only pull down the logic level on pin4. Pin4 is normally pulled to logic high by the resistor, which means mbed is running normally and does not get a reset. When pin5 is pulled low, this will pull down pin4 and reset mbed. The function of the diode is to prevent an active high level on pin4. This way you can still use a separate switch to gnd on pin4 or even a second pull down circuit to another pin using another diode to reset mbed without damaging the pin5 output driver since you wont short circuit it.