New answers tagged gpio
1
vote
How to buffer tri-state GPIO pin for higher source/sink current?
You have modified the question in between, the bidirectional LED is removed.
This circuit is a true three state buffer, no transistor is conducting without an input current. The saturation voltage ...
- 7,925
3
votes
How to buffer tri-state GPIO pin for higher source/sink current?
Here's a 'deluxe' expensive version, but parts count is still reasonable and the output current capability of the NCS2252s meets your 50mA constraint. R1..R4 are a 4-resistor network.
simulate this ...
1
vote
How to buffer tri-state GPIO pin for higher source/sink current?
For voltage hungry LEDs, like blue, you'll need to have the full 3.3V available for the LED. Here's a solution using a single 8-pin IC, the LM393, containing two comparators:
simulate this circuit &...
- 42.2k
1
vote
Push-pull/open drain; pull-up/pull-down
Software Only Perspective without too much technical IC stuff. It's an oversimplification but it gets the idea across.
GPIO Inputs
Some peripherals send both 0s and 1s. So no pull-up or pull-down is ...
- 11
0
votes
Hardware interrupt for PC from GPIO signal
The rule of thumb I use is this:
PC with regular OS: 5-20ms (also non deterministic)
PC with RTOS and GPIO: 10us to 1ms
General hardware timers on micro: 20ns (50MHz after that you need impedance ...
- 87.1k
2
votes
Hardware interrupt for PC from GPIO signal
You are wanting a 100us response time and that is simply impossible with the Arduino and PC in the loop.
Why? USB.
The Arduino communicates with the PC over USB.
USB has a polling rate of 1ms. There ...
- 164k
0
votes
Hardware interrupt for PC from GPIO signal
In Windows a time slice (time a process is allowed to run) is up to 20 ms.
This means that there can be large amount of jitter when you want to send and answer back from user space.
So, getting 5ms is ...
- 23.6k
0
votes
Hardware interrupt for PC from GPIO signal
at 115200 bps a single uint 8 talks 10 bit times so to send (assuming 8n1 line discipline)
your best possible response time is thus 20 bit times. or just under 180us
Be sure to set the receive ...
- 35.1k
3
votes
Hardware interrupt for PC from GPIO signal
As already stated in the comments, one character at 115,200 baud 8N1 (you've not specified) is ~86.8µs... so assuming a perfect zero-time response (i.e: no processing at all, not even just entering an ...
- 2,438
Top 50 recent answers are included