I have not found a way to do this yet. Most posts I see on this are using a 3rd party cart program like Shopify and allowing them to take care of the credit card processing. Even then I have not seen a reliable bluetooth card reader for generic installations. I have used the reader from Square and it works well with Square POS but no way to interface that with ERPNext.
As for the thermal printer and cash drawer, I have tried several over the past several weeks. None of them worked well with the iOS devices (iPads, iPhones). iOS kept dropping the bluetooth interface for some reason even though the devices never left a 1 meter radius of the screen. It was even worse with the wifi version of the printers and proved problematic even when the printer was plugged into an ethernet port on the network and the iPad was wireless to the same network. iOS just kept loosing track of the printer several times a day.
I had much better luck with Android OS and some of the network printing apps. I was able to put a thermal printer on the wired network and connect the Android tablet wireless to the same network. Printing was reliable, however I could never get the cash drawer to open on print. This is because all of the drivers for the printers are windows based. The cash drawer control is set and triggered in the windows driver. There are supposedly several linux drivers out there, but the only one I could get to compile was the one for Citizen thermal printers and it still would not open the cash drawer when used on a CUPS server.
You can install the printer as a wired network printer, and then share it out from a windows pc. This allows your other screen device to access the printer shared by the windows PC and the drawer will work. However, this is a clunky configuration at best.
I have also tried using the google cloud print to manage the networked thermal printer. This was an okay solution, but then the cloud print was unreliable and I would have POS receipts stuck in the queue for an hour or more. This will not work in a POS environment where you want to give the customer their receipt and their change from the drawer.
The best luck I have had so far was by using a Windows Surface Pro as a tablet and installing the printer drivers on it directly. I used a USB cable to connect to the printer and it opens the cash drawer properly with no issues. The barcode scanner also works much better with the Surface in tablet mode. I didn’t want to use windows devices as POS terminals but they tend to work every time as opposed to the iPad or the Android options.
I am currently experimenting with Chrome OS devices to see if I can get any of them to work well with a printer and cash drawer. I will probably post my results later as a separate topic.
So far the best solution was Windows devices. This may also be a better fit for your credit card readers, although I haven’t tried this and really do not have time for it in the near future. All of my POS stations are using an external credit card machine and then completing the sale in POS only if the card is accepted and approved. It is a little more time consuming but it works reliably and I will go back to testing other credit card solutions if I find a replacement for the Windows Surface PC’s. They are just too expensive but I have to use them because they work.
As for the models of printer I tested, the best performers were the Citizen CT-S310 and the Hillpow 80mm wide printers. Just about every cash drawer I tried with them worked as well. Epson printers worked but the drivers constantly trying to update themselves slowed everything else down so I got rid of them. Also only 4 out of the 10 cash drawers I tried worked with the Epson printers right out of the box. I didn’t have the patience to try to find alternate settings in the Epson drivers because the drivers were already causing to many problems in Windows. The absolute most configurable driver was the Hillpow printer driver. You could control just about everything from the driver menu.
If you have the time (money, and patience) to find a card reader solution for ERPNext, please share it back here. Many of us would like to know about it.
BKM