WiFi and Bluetooth print server module? - Page 1
Forum section: electronics / projects

author: ricko_uk
author_rank: Super Contributor
timestamp: August 16, 2023, 09:05:28 pm
content: #### UPDATE ####Hi,Following your feedback below, I am now looking for a WiFi (and possibly Bluetooth too) print serverPCB modulethat I can integrate to my custom PCB. But could not find any.Something like this (suggested by @fchk) but in a PCB module:https://www.tp-link.com/uk/home-networking/computer-accessory/tl-wps510u/Could anybody suggest any? Or the easiest and closest alternative solution to that?Thank you### ORIGINAL POST ###Hi,a client asked to add a WiFi and/or Bluetooth connectivity to a PCB that I am designing that goes inside the main enclosure of the printers they sell. So that said (standard, off-the-shelf) printer which normally works on USB does work through WiFi and/or Bluetooth. Effectively turning it into a wireless printer.To be clear, this has to be PCBhardware onlysolution i.e. :- either a Wireless IC/module on the PCB that I am designing so that such IC bridges the PC to the USB printer port via WiFi/Bluetooth DIRECTLY (i.e. an hardware only IC solution)- or a USB dongle to connect on the USB port of the printer itselfItcannotbe any service based solution where you pay subscription or other fees. Also it cannot have any software even if it is already fully developed and would need only downloading. It needs to be a hardware only solution (no software, no micros, no servers, no external infostructure, no external services). Literally the box itself that contains the printer will then turn the printer into a wireless printer out of the box (through my custom PCB).I was thinking about a WiFi/Bluetooth to USB bridge module if they exist? But could not find any.Or perhaps something like those ICs inside WiFi dongles?But haven't done any WiFi or Bluetooth designs before so any design and general advice as well as pitfalls to avoid are much appreciated.Most importantly...Any suggestions? Any ICs specifically for printers applications like this perhaps?Thank you

author: Shonky
author_rank: Frequent Contributor
timestamp: August 16, 2023, 09:29:51 pm
content: https://www.virtualhere.com/is a basically ready to go solution. Limited to 1 device for free.And also search for USB over IP. The IP bit gets you solutions using Ethernet, WiFi etc.https://usbip.sourceforge.net/It's old but should work with a small host at the device end like a Raspberry Pi

author: tychob
author_rank: Contributor
timestamp: August 16, 2023, 10:33:24 pm
content: If your going to use an SBC, a print server like CUPShttps://www.cups.org/might be more reliable than something that attempts to do USB over IP. But thats more of a unix sysadmin question.

author: fchk
author_rank: Frequent Contributor
timestamp: August 17, 2023, 06:51:04 am
content: What your client is looking for is a print server like this:https://www.tp-link.com/uk/home-networking/computer-accessory/tl-wps510u/There are plenty of those boxes - a new development might not be cost effective.Quote from: ricko_uk on August 16, 2023, 09:05:28 pmSorry, it doesn't work this way. Every Wireless or bluetooth module contains a microcontroller with firmware. The whole TCP/IP and the network printing protocols (IPP, BSD lpr/lpd, JetDirect, ...) absolutely require a microcontroller with software. The whole USB protocol requires software. And look: Even a tiny SD card (and all auf them) contains an 8051 or ARM7 with software in it. You can hide the software from the user, but this project can't be completed without a considerable amount of embedded software.fchk

author: ricko_uk
author_rank: Super Contributor
timestamp: August 17, 2023, 11:50:12 am
content: Thank you all,Following your feedback I also updated the OP.So I am now looking for a WiFi (and possibly Bluetooth too) print serverPCB modulethat I can integrate to my custom PCB. But could not find any.Something like this (suggested by@fchk) but in a PCB module:https://www.tp-link.com/uk/home-networking/computer-accessory/tl-wps510u/Could anybody suggest any?Or if they are not available, the easiest and closest alternative solution to that?Thank you

author: Jon_S
author_rank: Contributor
timestamp: August 17, 2023, 01:36:14 pm
content: Quote from: ricko_uk on August 17, 2023, 11:50:12 amI have never seen one myself. I would immediately think of a Pi Compute Module running CUPS as other people have suggested.Pi Compute Module 4For a commercial project I would definitely go with the Compute Module over a regular Pi, you can use an external antenna and eMMC is much more robust than flash cards. You will still need to set up a read-only root filesystem with a writable RAM partition, or loss of power without proper shutdown will cause filesystem corruption at some point.I designed an advertising device using an older version of the Compute Module and it worked well as a platform, quite easy to develop on and no issues in production.

author: fchk
author_rank: Frequent Contributor
timestamp: August 17, 2023, 05:55:25 pm
content: Linux devices have a big plus: there is plenty of software ready to use.But:- these devices are less robust as they need a filesystem that needs to be protected from users messing around and from power losses etc.- they are not instant-on- they require more powerThere are non-Linux solutions that use an RTOS. These are more robust.For further suggestions, please have your customer specify:- Does the printer use the standard USB printer device class?- What network printing protocols are required?- BSD lpr- HP Jetdirect via port 9100/tcp- ipp- SMB printing- other- Is SNMP required? What MIBs?- Bluetooth: Classic or LE? What profiles?SMB printing and IPP will require a Linux system. BSD printing is fairly easy as it's 40 years old. Jetdirect is the easiest one - the printer data is send via a single tcp stream without any protocol.The more boxes are checked the more work it is for you.CM4 modules still have poor availability and are expensive.Suggestion:https://www.8devices.com/products/carambola-3+ Cheap (26€)+ 2 Ethernet plus Wifi bgn (2.4G)+ USB 2.0 High Speed Host (for your printer)+ small (38mm*28mm)fchk

author: ricko_uk
author_rank: Super Contributor
timestamp: August 18, 2023, 08:47:04 pm
content: Thank you both