Raspeberry activation

Hello to all, 

work is in progress on the controller side.

We select Raspberry Pi 4 Model B as controller for the observatory. It is a medium performance controller and low prices, has a Linux operating system and is supported by Codesys. Many hardware peripherals are available on the market for Raspberry. CODESYS is the leading manufacturer-independent IEC 61131-3 automation software for engineering control systems. This provides us Ethercat fieldbus support, sophisticated motion libraries and communication libraries over IP. It is used for the brushless driving with DS402 profile.

Wifi connection is use for the communication with PC where Polypus is installed. Morover Raspberry has many GPIO lines useful for digital I/O connection and I2C line where many more complex devices can be manged.

For Raspberry OS installation the Raspberry Pi imager is used. It can be download from the official Raspberry website, it allows the OS selection. We used the raccomanded 

For Raspberry OS installation the Raspberry Pi imager is used. It can be download from the official Raspberry website, it allows the OS selection. We used the raccomanded

With this step the SD card is programmed ready to be inserted in the Raspberry board.

After that connecting Raspberry to: a video monitor, a USB keyboard and a USB mouse we have our own system running.

Other steps needs to be done in order to complete installation:

1. Insert pasword for pi user.
2. Connect wifi
3. Enable SSH protocol.

 

Now you have Raspberry with standard linux support. For application where the real time is important jiitter genarate by task context switch need to be reduced. For this porpose a stronger kernel have to be installed. It can be found at following address with the info for installation.

 https://www.raspberrypi.org/forums/viewtopic.php?t=250927 

On this Linux system we install the Codesys runtime for Raspberry. First step is the Codesys developing system (IDE) on a PC. Main purpose of this software is the application developping. It can be dowloaded for free with this link:

https://store.codesys.com/tag/product/list/tagId/38/

After download ad installation we have the environment running

For Raspberry runtime installation and programming an extra package need to be get from Codesys website from this address

 

https://store.codesys.com/codesys-control-for-raspberry-pi-sl.html

This package is not for free but without license it is possible use it in demo mode for 30 minutes after that it is automatically stopped. This is enough for developping and evaluation.

Package needs to be installed in the codesys with menu command: tools/Package manager.

After package installation with the command: tools/ Update Raspberry Pi we have this panel. Selecting Raspberry IP address, giving the password for pi user you set in the OS installation and pressing “Install” button you have codesys runtime on our own device.

Now Raspberry is ready to accept Codesys application.

In the next day we'll delevop a test application for motion movement ..