I had the idea to get rid of the cable from Duet to PanelDue (in my case to my own DuetMonitor with a Teensy and 5" RA8875 display), so I can place the Monitor where I want and even take it with me to another room (within reasons).
I didnt want it to connect to my router and have read about the ESPNOW protocol. Its working on 2,4G frequency but is a (multi-)point to (multi-)point data transmission protocol without connection to a network.
So I did some setup on a breadboard, and got a functioning prototype.
Then I ordered some PCBs, soldered the components on and got this:
Its working!! and no cable.
The PCB is 3cm x 4cm. I went with a 18650 LiPo battery holder with charger, so no cable at all other then charging.
Using and charging at the same time is possible with this battery holder.
But you can go with this:
mount it at the case and feed the voltage to the PCB. Power it with a wall wart or powerbank. A good powerbank should last several hours. The PanelDue gets the voltage through a short cable.
The PCB on the printer should be mounted where it can receive and send proper.
Because a panel of 4x4 PCBs was only a little more charge with p&p, now I have roughly 30 PCBs that I dont need.
This is a great community, so if you want you can get them for €0,75 each + €1,50 postage to Europe and US (up to 50g), €3,70 above 50g (from Germany).
The ESP8266 has to be programmed with Arduino IDE with ESP8266 Addon over serial. You can get the source code via email.
You can choose between 8 IDs (Each pair has to have its own ID).
You can choose between 4 WLAN channels (1,4,7,11).
Set A or B for the ID. (There is no dedicated Master or Slave, each pair has one A and one B on the same ID and channel, and it doesnt matter which is on PanelDue and Duet side).
The serial port can be set to 19200, 38400, 57600 or 115200. Typically set to 57600 for Duet.
Its possible to use one PanelDue for different printers, but not at the same time: Change to another ID (and/or channel) on PanelDue side, press reset and you are connected to the other printer.
If you are unable to solder and program the PCB I can do this, but I dont have the components laying around, so I have to order them.
But it will then be €7 per PCB and I dont make a profit on it (I have no intention to make a profit).
So if someone is interested PM me.
And here is the schematic: