wifi thru Xbee need schematic of the electronic board ultimaker

[Catlord 17]

Hi,

I'm using Xbee system on several instruments ( UAV, Theodolites,...) The Xbee replace efficiently a USB cable thru an ad hoc link up to 1500m.

Xbee is composed with two parts:

one USB/TTL converter :

and one wifi system:

As you can see there is an USB plug in it so it could be plug n play with the Ultimaker, you just plug the Xbee in the USB port and that's it. But it would let the Xbee on the side on the UM and I would rather prefer to have it hidden in the bottom part.

And that's where you come to help me

Does anyone have the schematics of the electronic UO+ board (last revision, same as UM2) ? I need to catch the Tx and Rx wires on the board (if there are some plugs somewhere).

Once I will have these, I will present you a complete DIY "My Ultimaker works in wifi without SD card ^^"

Best regards,

Cedric

[Labern 775]

you mean like THESE ?

[Catlord 17]

Yeah

thanks you, it's printed, I will check it this evening and find where to plug the Xbee.

Merci mister

[neotko 1,417]

You need to use serial 3 for that I think.

[Catlord 17]

The USB port is directly connected to R6/R7 and R8 (R8 seems to be the +5V)

I thought there was some pins directly available before the treatment of the signal but it seems it's not the case :/

I will check the Serial 3 way to see where it goes.

[neotko 1,417]

If you have any progress with this please share, I'm really interesting on connecting stuff to the serial outputs to control other stuff.

[Catlord 17]

Yep, I will update as soon as I have results.

at minima, I willl have the xbee plugged on the USB port

[Catlord 17]

Hi,

I tried to use the Serial 3 port with no success. I Have reversed Tx and Rxn combining them between serial 3 and the Xbee: no sucess. (combining the Tx and Rx is the best way to find a potential problem

So, next step:using the USB B cable, plug a USB a to mini USB converter and plug the UXBEE directly in the USB B port of the Ultimaker.

If this works, I will try to find a short USB B to Mini USB cable and make a proper installation.

By the way, there are several Xbee systems: some with antennas (rubber duck type), other without. Those without antenna are working great for inside applications. I'm working in a reserach center and we have concrete walls of 1.5m. I'm able to control an instrument at 30m distance with a 1.5m wall between PC and instrument with just a small window (30cmx20cm) in the concrete wall

Anyway: If it works, I will make a full review (link to buy stuff, assembly, parameters, ...)

My electronic skillls are basically 0, I can't measure the signals on the serial 3 port (if there are) and say what kind of signal it is. If anybody knows...

[gpb01 23]

... next step:using the USB B cable, plug a USB a to mini USB converter and plug the UXBEE directly in the USB B port of the Ultimaker.

If this works, I will try to find a short USB B to Mini USB cable and make a proper installation.

...

 

I don't think that this can work ... but you can still try

... the USB port is not a simple "serial connection" ... the USB that you have on the UM2 main board and the USB that you have on the Xbee are USB "device", both made to connect to an USB "host" (e.g. the USB port on the PC).

The differences between a USB host and device is that the "USB host" initiates all communication on the bus, the "USB device" only responds when asked by the host. For Details see the specs on usb.org.

Guglielmo

Edited September 25, 2015 by Guest

[Catlord 17]

Not sure about that because we use the XBEE on several instruments that are designed to work with direct USB connexion and it works fine

The USB B port on the UMO isn't powered with 5v so I will have to power the XBEE module (I'll pick à 5v output on the UMO board)

Does anybody knows the USB parameters used on the UMO ? is it a 9600bauds or a 57600 bauds connexion ?

[gpb01 23]

If you look on the first page of the schematic, you will find the USB (J3) connected to the ATmega16U2 which convert from USB to serial.

The serial I/O is on the pin 8 and 9 (PD2 and PD3) where you can find 2 resistors, R13 and R14 and you have the two signal named PE0 and PE1.

Now, if you look on the top left, you have the ATmega2560 (U1 - the main MCU), and PE0, PE1 are connected to pin 2 and 3.

So ... if you really want to risk ... you can :

1. disable the ATmega16U2 MCU setting LOW (connect to GND) the pin RESET (pin 24, TP8 or pin 5 on J2)

2. connect the TX from the XBEE (if the XBEE work at 3.3V you MUST insert a level translator) to the RX pin of the ATmega2560 (pin 2 - PE0)

3. connect the RX from the XBEE (if the XBEE work at 3.3V you MUST insert a level translator) to the TX of the ATmega2560 (pin 3 - PE1)

4. cross the fingers and hope that work

Disclaimer : I have not tried this thing and it could also damage your card. Do at your own risk !!!

Guglielmo

[gpb01 23]

Sorry ... just read you answer ... my notes are for UM2 board ... I don't know the UMO board ... :(

Guglielmo

Edited September 25, 2015 by Guest

[Catlord 17]

Hi Guglielmo, on the new batch of UMO+, the board is a UM2 board

I don't want to do a tricky thing there. My scope is to find how to have an xbee xworking with the UM without doing some small electronic stuff on the board

If there are some pin directly available: fine, otherwise I will try with the USB B but if nothing works, I will leave it like that.

As Neotko mentionned, there are serial pins (SERIAL 3) but it seems it doesn't work. Maybe I have the bad baudrate. The Xbee must be configured with the correct baudrate in order to work properly. Is there any source code available where we can find the baudrate somwhere ?

[gpb01 23]

Yes, in the firmware sources ... HERE

Mmmm ... I think that the baud rate is 250000 baud !!!

Guglielmo

Edited September 25, 2015 by Guest

[Catlord 17]

Not sure XBEE can do this but I will check

125k yes, 250k not sure

[Catlord 17]

I have seen that the serial port can be configured to a discrete value (125k,250k,58k,....)

I will give it a try this week end.