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What can I connect to GPIO?
GPIO stands for General Purpose Input/Output. It’s a standard interface used to connect microcontrollers to other electronic devices. For example, it can be used with sensors, diodes, displays, and System-on-Chip modules.
How do I get 5V on my Raspberry Pi?
The 5v power pins are connected directly to the Pi’s power input and will capably provide the full current of your mains adaptor, less that used by the Pi itself. With a decent power supply, such as the official 3A adapter on the Pi 4, you can expect to pull about 1A to 2A.
How do GPIO work?
Stands for “General Purpose Input/Output.” GPIO is a type of pin found on an integrated circuit that does not have a specific function. These pins act as switches that output 3.3 volts when set to HIGH and no voltage when set to LOW. You can connect a device to specific GPIO pins and control it with a software program.
What kind of resistor is on Raspberry Pi input?
The 1KΩ resistor on the input is for limiting the current that can flow through the LED. The 10KΩ pull-up resistor is internal to the Raspberry Pi. Be sure to set the pull-up option when you set the pin to input mode.
Why does the Raspberry Pi see the pin Hi?
When the input is open, no current will flow through the detector and the Raspberry Pi will see the pin hi due to the pull-up resistor. When the the input is connected to ground, current will flow and the Pi will see the the pin as low, since it is effectively connected to ground now.
How does an opto coupler work on a Raspberry Pi?
This is detected by the internal photocell which controls the output. Because there is no electrical connection between the input and output sides, opto-couplers are handy for connecting between very different voltage levels. They are also excellent at preventing the introduction of electrical noise into a system.
How to interface Raspberry Pi and plc?
Modbus TCP for many others: using pymodbus this blogger was turning on a PLC from his pi built lightswitch: http://simplyautomationized.blogspot.com/2013/09/home-automation-project-part-3-webapp.html Hope that helps.