@pea13 well, it is dependent on the Task, since I see most clusters not connected to any peripherals, and are just doing computational tasks, we can prevent power deprivation give 10w minimum to each board…
so if you wanted 5 boards, you would need up to 50w,
you can use a wall powered USB Hub, like this one,
You can Take inspiration from @Birty’s Miner project, he has multiple VIM3’s attached to a backplate, providing data and power…
If you’re interested in a cluster then I can get you one of my backplane boards to test if you want. Happy to make you one and let you have it for the cost of postage - be interested to get someone else using one! It provides power and networking via the usb connection on the vim3 boards - so only one power supply needed - can do up to 3A per port. All I would ask is you feed back any issues and share results here.
Can also do you a good deal on (new) vim3 boards if you want to buy them at the same time!
No this is a powered backplane for running multiple vim3 boards in a cluster. Each vim3 connects via a usb c plug on the board and each plug provide 5v at up to 3A. There is one controller port and 4 downstream ports based on a usb hub chip and power control chips. These provide individual power control to the ports (for hard reset) and also current limit in case of shorts etc. The same usb c socket on the vim 3 is used to provide ethernet over usb.
This means you need one power supply (I’m using am LRS-100-5) this backplane and vim3 board to set up a cluster.
Board also has a step up converter to power 12v fans for cooling the cluster and ability to measure current for both mains input and each of the 4 downstream vim3 boards.
All the info from the backplane is interfaced with the vim3 used as a controller over an I2C interface (the 3 wires over the boards in the picture above).
Have also brought all this info out onto a web interface that also runs on the controller board
There’s a couple of small microcontrollers on the backplane to handle the I2C Comms and then one of the VIM3 boards does the rest. But not need to do any control - out of the box it works as a 5 port usb hub with 3A port current limited at 3.2A per port
Hello Birthy, very nice offer. We want to built a low-power VIM3-cluster in combination with LoRaWAN to send data from several VIM3 with object-recognition to our central server.
Do you have any description of your backplane board? We would be very much interested to get one for testing.