Cheap Bluetooth-Serial link

Hi there

I would like to controll my printer across the room wirelessly. I’m thinking of hc-05 bluetooth links, cause they are cheap, easy to set up, relyable and have a uart interface.

I saw some mods of this kind for other printers but i couldn’t find anything about this for the vertex printer.

The point is, can someone tell me if there are spare serial RX/TX pins on the vertex motherboard? I spotted SPI but no UART.
What do you think of this idea?

the RX/TX pins that the Vertex uses are connected to the FTDI chip.
If you could change the RX/TX pins in the firmware you can use other pins that are available on the Vertex PCB.
The Atmega 2560 has multiple UART interfaces but I don’t know if those pins are in use. If that’s the case you can try with the SoftwareSerial library (not sure it’s fast enough).


Thanks for the tip!

I just comapred the pinout of the atmega chip to the mainboard’s schematics. Unfortunately serial 1 is wired directly to the ftdi and the other serial pins are not wired anywhere. I might try a software serial library, but i dont have any expirience since i never used softwareSerial before.
Does anyone have some expirience with software serial? Does it withstand the high baudrate without slowing down the printer?

Ps: i just found this:
Is it a good idea to decrease marlin’s standard baudrate to make software serial working?

I’m very new to 3d printing

I would suggest you try with the default baudrate of the Vertex (you can view the baudrate in Repetier printer settings).

Here’s a link about SoftwareSerial on the Arduino website:

You need some experience with C++ and Arduino in order to accomplish this.
I wouldn’t do it and just use a Raspberry Pi with Octopi. Works standalone and has webcam support.


Keep in mind though if there is one send/receive error things will go (horribly) wrong.

The problem i have with octoprint is the price point. It’s ~ 100€ (in my country, without picam) vs 10€ bluetooth links. It also requires hours of learnig/setting up/enclosure printing.

I found this here:
It’s a serial to SPI converter. It could bridge the mainboard to the BT serial link. But i have no idea if there is any latency or what so ever.
What do you think of this idea?

A Raspberry Pi shouldn’t cost €100, or you can order a cheap Chinese version?


Of course, my mistake. It’s with piCam.
Prices in CHF (from
Raspi 32.-
Wifi 17.-
Sd 9.-

Sum 58.-
Picam 42.-

Sum 100.00

I think keep using print from SD, until i have enought time and money…

A Wifi connection is not always more reliable than a Bluetooth one. If the connection is severed your printer will either stop or go wild.