8
votes
Accepted
SPI bus layout with 8 slaves
Route with stubs or with loop?
There are two routes your bus could take: either a loop through all chips, or with stubs to each chip:
Currently your schematic takes route 1, which has the benefit of ...
- 11.2k
8
votes
SPI bus layout with 8 slaves
A golden rule (or rule of thumb) is that if the signal wavelength is more than 10 times the transmit path length then it's unlikely that a termination resistor will be needed. Your clock signal is 50 ...
- 504k
4
votes
Accepted
Why would STM32 have a diode in series on the NRST line if it's supposed to get signals from STLINK?
Externally, you have to pull down the NRST signal to get the wanted effect (reset the device).
The diode will allow this - if you put a low level on the diode, it is forward biased and current will ...
- 18.3k
4
votes
Why would STM32 have a diode in series on the NRST line if it's supposed to get signals from STLINK?
There are subtle details that need to be understood why would a diode be on NRST pin.
And you assume the NRST pin only connects to a debugger, but in another example of a system in the application ...
- 198k
2
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Is the NRF24L01 + PA + LNA good enough for a simple quadcopter drone?
The big problem with nRF for drones is lack of frequency hopping. You set a fixed carrier frequency and there's a big chance of getting interference. There are cheap radio links specifically made for ...
- 2,405
2
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Is the NRF24L01 + PA + LNA good enough for a simple quadcopter drone?
Over a few tens of metres and to a drone (clear line of sight, good ground clearance) my experience suggests it should be able to be very acceptable. Its entirely doable but not something you should ...
- 155k
2
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EEG electrode inputs have an ESD protection array to ground plane; but where would it return?
I was going to ask for a diagram of where this EEG lives with respect to ESD sources -- but decided I'll answer in general.
ESD comes from somewhere. It could be a cart, the EEG tech, some rando ...
- 50k
1
vote
Accepted
EEG electrode inputs have an ESD protection array to ground plane; but where would it return?
The key point to be grasped to understand the question being asked is that
there is NO ultimate sink that the charge is flowing towards.
ESD discharge deals with transfer of charge to achieve ...
- 155k
1
vote
Why would STM32 have a diode in series on the NRST line if it's supposed to get signals from STLINK?
It MAY not be relevant but as well as the points suggested in other answers, the diode will ensure reset occurs even for extremely short input pulse lengths.
IF NRST external is only driven low or ...
- 155k
1
vote
Why would STM32 have a diode in series on the NRST line if it's supposed to get signals from STLINK?
The NRST pin is an Active-Low pin, which means that the function gets activated when a low voltage is supplied to the pin. This effectively means the pin should be pulled to GND to activate the Reset ...
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