Connect 3 raspberry pi to a VNC - raspberry-pi3

In my project I need to use 3 raspberry pi independently ,each one controll a relay that cut off/on thr power on a motor ,I want to control the 3 pi with a single desktop computer. My question is can I have 3 VNC on the same computer ,or there is a way to control the 3 raspberry pi from one VNC.

Yeah, you can control three RPI with one computer, but you need three Ethernet cable connected to the same computer.

Related

How is the last digit in a USB Device Path Assigned/

I am trying to have a Raspberry Pi Zero emulate a Cisco USB console interface (non-FTDI version). At a high level this is actually not that difficult:
The g_serial driver running on the Pi can accept Cisco idvendor and idproduct parameters, so it will look roughly the same on a lsusb output
The Linux host uses the same driver, cdc_acm, to connect to the Pi and the Cisco Device
The one problem I am having is that the kernel device path is slightly different between the two.
Cisco: /sys/bus/usb/devices/1-1.4.2:1.0
Raspberry Pi: /sys/bus/usb/devices/1-1.4.2:2.0
The Cisco's device path ends in :1.0 and the Raspberry Pi's ends in :2.0. I know 1-1.4.2 comes from the USB hubs I am using on the host, but I do not know how the numbers after the : are assigned.
So my questions are:
how is the last number assigned in the devpath? does it come from the host or attached device?
is there anything I can do to the g_serial driver to make it better emulate the Cisco device and appear as :1.0
Note: I am not trying to fix this with a udev rule. My goal is to completely emulate the Cisco device with the Pi.

Delay HDMI loading on Raspberry Pi & Win IoT

We have device with follow configuration:
Raspberry Pi 3 with Windows 10 IoT Core
4inch HDMI LCD with touch pad
Several external devices connected to 5V, GND and GPIO pins
All the scheme consumes 12V directly and 12V separately for other devices.
The problem is: Windows IoT some times not loading, presumably because of monitor power consuming.
Is it possible to configure programmatically or via Windows Device Portal to load HDMI after Windows IoT is loaded?
First, to determine if this issue caused by HDMI. You can check if this issue caused by HDMI via disconnect the HDMI to see if the system can boot up every time. (Use Windows 10 IoT Core Dashboard application to find its IP address. Via ping its ip address or device portal to see if the system has booted up.)
If the system can't boot up when you attach the HDMI pad, you can supply the power for HDMI pad separately. There is a power supply port, something like this:

I can't connect my raspberry pi with my laptop

I had a raspberry pi I want to connect to my laptop and use the raspberry pi directedly from my laptop, I try PuTTY and VNC following tutorial on youtube, but can't get them to connect; in PuTTY had connection refused, as for VNC connected with the pi.
As said in the comments you need to enable SSH on your pi.
If you have a screen you can use to view the desktop, it's pretty easy, enter:
sudo raspi-config (in to a terminal) navigate to interfacing options and you will be able to enable both SSH and VNC.
If you do not have a monitor or any way to view the desktop of your pi, you will have to do it the hard way by copying a file to your pi SD card to enable SSH, here is a link to a tutorial on how it works Enabling SSH on pi without screen
Honestly, though, the first option is the best, easiest and most foolproof.

How do I connect my windows 10 PC to my Raspberry Pi 3 using Wifi Direct?

My Raspberry Pi 3 (running Raspian) is a robot and needs to drive around.
At home, I control it using Windows 10/Putty over SSH. However, in 2 weeks I will be demonstrating it in a place where I have no control over the wifi connection, and I don't want to be reliant on a potentially heavily firewalled network.
I read that Wifi Direct would allow me to SSH into my Raspi (and thus control it) using my Windows 10 laptop, without using an existing wifi network. My laptop supports Wifi Direct. However, all tutorials appear to be concerned with connecting the Raspi with an Android app, and not windows 10/Putty.
How do I connect my windows 10 laptop to my Raspi using a Wifi Direct connection?
So what I did is use a spare router as a switch to create a local wireless network, and connect both my laptop and my pi to it. I could hence establish a ssh connection.

Can't use RPi 3 GPIO using computer as power supply

I have a raspberry pi 3 that I powered with my computer directly and I can not use the GPIO pins because they don't send anything.
Do I really need a power supplier?
Yes, you definitely should use a "real" power supply, as mentioned here: Raspberry Pi, Powers supply
If you use any USB Ports or mobile phone chargers it can happen that some functions are not available, because of lack of power and/or voltage.
Here are the exact specs: FAQ - Power requirements
Quote from the FAQs:
2. CAN I POWER THE RASPBERRY PI FROM A USB HUB?
"It depends on the hub. Some hubs comply with the USB 2.0 Standard and only provide 500mA per port, which may not be enough to power your Raspberry Pi. Other hubs view the USB standards more like guidelines, and will provide as much power as you want from each port. Please also be aware that some hubs have been known to “backfeed” the Raspberry Pi. This means that the hubs will power the Raspberry Pi through its USB input cable, without the need for a separate micro-USB power cable, and bypass the voltage protection. If you are using a hub that “backfeeds” to the Raspberry Pi and the hub experiences a power surge, your Raspberry Pi could potentially be damaged."

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