Octoprint with Raspberry Pi3 B+ USB vs GPIO connection  

Re: Octoprint with Raspberry Pi3 B+ USB vs GPIO connection

Some wish to use the GPIO connection and EINSY power to avoid another power supply. However, I would like to point out a benefit of using USB and a separate power supply.

I often power down the printer to perform work on the motors. Because my Raspberry Pi is on its own power, I don't have to wait through a long Pi and Octoprint reboot each time the printer is shut off. Octopi simply keeps running while the printer is off. If my Pi were on printer power, the delay would be annoying.

Re: Octoprint with Raspberry Pi3 B+ USB vs GPIO connection

(note you cannot run a B+ with power supplied from the Einsy, it cannot supply the required current.)

RE: Octoprint with Raspberry Pi3 B+ USB vs GPIO connection

So the only difference between USB and using GPIO is the need for an extra power supply?

All other functionality is the same?

RE: Octoprint with Raspberry Pi3 B+ USB vs GPIO connection

Posted by: luke.m8

So the only difference between USB and using GPIO is the need for an extra power supply?

All other functionality is the same?

You will still need a separate power supply regardless of the option you choose. GPIO cannot supply enough current for the B+.

RE: Octoprint with Raspberry Pi3 B+ USB vs GPIO connection

Thanks!

RE: Octoprint with Raspberry Pi3 B+ USB vs GPIO connection

as long as you DO NOT connect the 5v pin to the einsy , the gpio route seems better IMHO yes, an external wall wart for a pi3 will be needed, but you will be happy with that as a setup

keep ground pin 

RE: Octoprint with Raspberry Pi3 B+ USB vs GPIO connection

I am running a RPi3 A+ && Pi Cam via GPIO pins on the Einsy with no problem, whatsoever (power requirements for A+ are lower).

Pi is in a case mounted to the 3030 rail below the control box with a custom connector cable attaching the Pi to the Einsy.

I have had all sorts of Pi setups in the past, most recently a 3B+ running on its own power supply and controlling things via 4 DC relays. It was great to be able to turn the printer on/off, lights, fans, etc. but I just wanted simplicity with my Prusa (my other printer(s) are for tinkering).

Powering off isn't a big deal. I open the Octoprint app on my phone and tap "Shutdown" and by the time I put down my phone the Pi has powered down. When I turn the printer back on, same thing. Octoprint is already up, running and connected by the time I'm able to load the server page to get a print going.

RE: Octoprint with Raspberry Pi3 B+ USB vs GPIO connection

Can you elaborate on this 'custom connector cable' that you're using?

RE: Octoprint with Raspberry Pi3 B+ USB vs GPIO connection

I guess we don't know what the 2 extra pins that are connected via the header vs USB are for?

2 pins in J19 connector.    13,14     Is it a reset and ground pin?  What triggers octoprint to do anything on these pins?

RE: Octoprint with Raspberry Pi3 B+ USB vs GPIO connection

Posted by: Migamix

as long as you DO NOT connect the 5v pin to the einsy , the gpio route seems better IMHO yes, an external wall wart for a pi3 will be needed, but you will be happy with that as a setup

keep ground pin 

What's the advantage of this? The free Usb port?

RE: Octoprint with Raspberry Pi3 B+ USB vs GPIO connection

If you use a 3A+ you don’t need the separate power supply, so you’d be getting your USB port back, using the Einsy GPIO and quicker Octoprint.

So you can tastefully mount your rPi and run a single cable to your MK3/S control box for power/data.

RE: Octoprint with Raspberry Pi3 B+ USB vs GPIO connection

I know this is an older thread, but I was curious about the extra 2 pins as well (they appear to be GPIO 3 and 4 on the Pi). Are these "REQUIRED" for a direct serial connection?  I checked the schematic of the einsy board and it appears that one of those pins is connected to ground on the einsy (this connects to GPIO 4, I think).  The other pin (connected to GPIO 3) looks like it is connected to a reset line through a transistor.

RE: Octoprint with Raspberry Pi3 B+ USB vs GPIO connection

Here is a screen grab of the relevant schematic section.

RE: Octoprint with Raspberry Pi3 B+ USB vs GPIO connection

@littleredtoaster

Can you elaborate on what you had to do to get the serial communications working between the Einsy board and the Pi3 B+? I have the external USB cable solution working, but when I connect GND, TX and RX pins between the 2 boards (separate power) and turn on RPi port in MK3S settings, octoprint can't connect to the printer. Do I need the extra 2 GPIO pins connected as well?  Can't figure this one out and can't get a clear answer from the message boards (yet.) 

RE: Octoprint with Raspberry Pi3 B+ USB vs GPIO connection

@littleredtoaster

Hey, I just saw your cable on Ebay which brought me to here. Let me first say I am very new to all of this so please go easy on me. I want to get octoprint working with my mk3s which is still on its way to me. The only good guides I see for setting up octoprint are using the pi zero which seems to be garbage. So I am happy to get a pi 3 but every mount I see that is printable for the pi 3 is for the b+. Being that I don't think I will need all those USB ports and the lower output is exactly what I am going for. I would be happy to buy your cable. Can you maybe point me to a guide that has exactly the setup you have? I love the picture you have above. It looks clean and easy to use. I purchased the pi camera and would loved to get it all ready to go before the printer comes in. Thanks!

RE: Octoprint with Raspberry Pi3 B+ USB vs GPIO connection

hi Guys, I'm trying to implement this mod. I've got the wiring connection, but the OctoPrint has hard time connecting with the printer. Is there some software setup to be done so the RPi can communicate with the printer?

Regarding powering the board. I've got a tiny circuit that converts 24v to 5v, it works perfectly powering the RPi 3 B+. How should I use the Einsy GPIO to RPi serial connection? Should it not use the 5v from Einsy and just power the RPi using my 5v source? How about the Ground Wire?

Thanks!