2

I am working on a project at a company where I read the temperature of a machine with a raspberry pi. I have downloaded the necessary program and can use it through Wine.

In addition, I have made a python script that takes a screenshot of the screen every 10 seconds, cuts out the necessary cells, reads these values and saves them in a csv file.

Now I want to keep the raspberry pi there for several weeks to read the machine during this period. So far I have only tested it with a monitor and the program worked perfectly. Then I thought if I pull out the HDMI cable now, the program will continue to run and I can connect it to the machine. But when I pulled out the HDMI cable, the program no longer recognized a screen and only black screenshots were made.

Is there a way I can make the raspberry pi think that there is a monitor connected so that it continues to take screenshots of the program?

2 Answers 2

0

You can also buy a 'fake HDMI dongle' i.e. at aliexpress for less than USD$ 2. The dongle plugs into an HDMI port and simulates a non-existing display with a given resolution.

Nevertheless, I fully share @Milliways opinion that screenshot is a poor way to capture data.

0

The Pi4 differs from earlier models in that there is no default resolution. No monitor - no screen.

You can't capture a screen for a computer which doesn't have a screen.

There are a number of potential solutions.

Create a virtual screen - any VNC server has the ability to do this.

RealVNC (included in Raspberry Pi OS) can either share the monitor screen or create a virtual screen. There is an option in raspi-config to set default VNC resolution which creates a screen with or without a monitor.

You can certainly view the virtual screen on a remote machine. I do this routinely and can view the same screen on monitor or remotely. Whether you can capture without a connection I don't know.

Frankly capturing a screenshot seems a poor way to capture data.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.