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4

In general the reason electronic engineers prefer pull-ups to pull-downs is that in silicon N type (NPN bipolar or N-channel FET) transistors are better than P type transistors (PNP bipolar or P channel FET). This meant that when ICs were built out of 1 type of transistor they were built out of N transistors and as a result they were much better at pulling ...


3

I had the exact same problem. Solutions are: Turn on the screen first. I give it 4 seconds. Slower SD cards won't have this problem, since the Pi waits longer before checking for a monitor. Add/uncomment hdmi_force_hotplug=1 in /boot/config.txt. Turn off OpenGL. sudo raspi-config --> Advanced Options --> GL Driver --> G1 Legacy. Get a HDMI screen.


2

Yes I think it is possible, for example you can use FIFO file: ~$ mkfifo /tmp/input.audio.fifo Write a python programm like this (warning, this script record only 60sec of audio, you can adjust this): Python code REF. To install: python -m pip install pyaudio """PyAudio example: Record a few seconds of audio and save to a WAVE file.""" import ...


2

In your code Output code you have not define bcm2835_spi_setClockDivider(BCM2835_SPI_CLOCK_DIVIDER_64); // 4MHz clock with _64 , you not divide the clock. Per default the clock freq. is 250MHz, so you receive with 250MHz clock and you send with 64Mhz... which would explain why it would work when a single program is used and the frequency is the same. ...


2

Well, now the Raspberry Pi 4 model B has come out with two Micro HDMI ports, so I think that gives the best solution to the problem? If you don't want a Pi 4, it seems that buying two Pis may still be the next best option. But I would use x2x instead of Synergy to connect them, because it is free software. For additional displays, I noticed that there are ...


2

As you well said, you can't output HDMI video into a laptop. I don't know of any devices as of now, however, I recommend using VNCServer and Viewer. It's almost as simple as using an HDMI. Just install VNC Server in your raspberry using these steps. Install VNC Viewer in your laptop and connect the raspberry with the laptop with an UTP cable (The one you ...


1

No, the GPIO pins can not be used to drive a DC motor. They can only supply a few milliamps of current at 3V3 which will not be enough. In addition driving any inductive load direct from a GPIO is likely to destroy the GPIO and the Pi. An inductive load is such as a DC motor or a relay coil. You need a motor driver board or chip or discrete components (e.g. ...


1

Question The OP has the following device. He would like to know how can Rpi interface this device. Question Analysis The OP is asking 4 little questions. All 4 questions are OK, except the third question repeated below that causes some confusion. How can I bring the input voltage down to a safe level that I can plug in to the GPIO output pins? The OP ...


1

Unlikely. The Pi's GPIO peripheral supports clearing a set of GPIO in one instruction and setting a set of GPIO in one instruction. You specify the GPIO to clear/set with a 32-bit mask. E.g. to select GPIO 0-7 you would set a bit mask of 0x000000FF. The unselected GPIO are unaffected by the clear/set operation. For simplicity the following examples ...


1

According to this: https://www.raspberrypi.org/documentation/configuration/config-txt/video.md If in your cofig.txt you set: sdtv_disable_colourburst=1 then the composite output of RPi is monochrome.


1

Sorry to react almost 7 years later... I believe this problem could be related and solved to overscan. Either set your TV to display every pixels without cutting the border. Or, on the Pi specify that some pixels are not visible and should not be used. And this can be done in /boot/config.txt # uncomment this if your display has a black border of unused ...


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