AXA Remote Ventilation RV2900, Window opener

[martijnspaan]

Hello,

I have assembled this board. MCP2003, 2 3k3 Resistor. LIN bus to pin 3-4 of the AXA. The other one connected to pin 1 of the AXA 8 volt.
My USB-->TTL is a PL2303HX.
On the TX pin there is 3,3 Volt

I have
- connected the ground (orange) to the WAKE of the MCP2003
- connected RX of the MCP2003 to TX of the USB-->TTL
- connected TX of the MCP2003 to RX of the USB-->TTL

When I assembled this, I messure 1 Volt on the TX of the MCP2003, is this normal?

In Linux I use Minicom with the following settings:

- 19200 baud
- 8 databits
- Parity: none
- stopbits: 1
- hardware flow control: off
- software flow control: off

I don't get any response from the AXA
I changed the RX / TX,
Port settings change, no solution

Unfortunately the PL2303 is not compatible with Windows 8m, so I cannot test it with hyperterminal

Does anyone know what I am doing wrong here or maybe a hint or tip

thanks!

Greetz

Martijn

[raymonvdm]

I did not test it with a axa power supply yet because i don`t have one and it is mandatory for the interface to work.

Did you also test it using putty (which is available on Ubuntu)

[martijnspaan]

No, the problem is, its a esxi server with Ubuntu server... so no X or display for putty

But if thats the only option to figure out whats going wrong I have to get another computer with Win7 or another cable
Any other way of solving this issue?

thanx

[martijnspaan]

update:

I tried with a Windows 7 machine.
When I try to open a serial connection, I get an error.
when I remove the 2 resistors I get a connection but no response or status, or anything...

[raymonvdm]

Maybe you can try it using a RaspberryPI since they are cheap and you don`t have an USB pass-through issue like my ESXi 5.1 server does. Although it looks like the converter is working the OS can`t get exclusive access to it. Therefore i`m using a raspberryPI to host my cardreader instead of an ESXi server

[martijnspaan]

Hello,

I bought a Raspberry, the same cable as you are using.... it is still not working though... But, I get some response, although, rubbish. I get unreadable characters back... I played around with the settings...same result.. Switched the RX / TX line... used another MCP2003... Pin 1 or 6... it doenst matter right... I gets 8 volt back from the unit...that's the whole idea..right...?

frustrating

[kabelmanroel]

Hello,
I've been trying to build this interface, and now the picture is not very clear, I must say. How to make the interface. After some good-looking, i have managed but I soon against communication problems. Therefore I reviewed the circuit.
1st thing I noticed is that it is very difficult to see that pin 3 and 5 are connected. Using the board.
2nd I can not explain why pin 8 (where 8V on it) get connected with a resistor to pin 1 (RxD) 5V. This resistor i have left out!
Unfortunately did not really improve. With a short cable to the window opener is fine but for a 2 meter goes all wrong.
3rd So i look for on the internet. I've seen on the master 30KOhm a pull up resistor on the LIN bus. This I have tried my converter and now have good communication over 5 meter cable. (have not tried longer because 5m cable is enough for me)
ps sorry for my bad English

[kabelmanroel]

Building tip:
* pin 3 en 5 are connected together by the board
* Found where to order MCP2003 http://www.conrad.nl/ce/nl/product/1086 ... archDetail
* remove resistor between pin 1 and 8
* add 30K resistor pin 6 and 7 (pull up for LIN bus)
* use a usb converter 5V TTL version only ( PL2303 )

[kabelmanroel]

Programmed a working Python sample script for raspberry:

Code: Select all

import time
import serial

# a= time to wait between characters and wait for response back from device
a=0.1

# I used a USB to serial converter PL2303 on ttyUSB0 to connected to the device
# configure the serial connections 19200N8

ser = serial.Serial(
	port='/dev/ttyUSB0',
	baudrate=19200,
	stopbits=serial.STOPBITS_ONE
)

ser.open()
ser.isOpen()

# ask user for what command to send
print 'Enter your command. Insert "e" to Exit the application.'
input=1

while 1 :
       # get keyboard input
       input = raw_input(">> ")
       # Exit program if input = e
       if input == 'e':
           ser.close()
           exit()
       else:
           # wake up device
           ser.write('\r')
           time.sleep(a)
           #Loop for each input character and wait a little for device to get ready for next charachter
           for c in input:
                  # send each the character to the device with little pause between
                  ser.write(c)
                  time.sleep(a) 
           # Add finish command Return + Linefeed
           ser.write('\r')
           time.sleep(a)
           ser.write('\n')              
       out = ''
       # let's wait before reading output (let's give device time to answer)
       time.sleep(a)
       while ser.inWaiting() > 0:
           out += ser.read(1)
       if out != '':
           # Print output from device
           print out

[martijnspaan]

Hi,

thanks for the update. So, the resistor between 2 and 7 stays in place..???

greetz

Martijn

[kabelmanroel]

Yes 3.3KOhm pin 3 and 7 original circuit description
pin 7 = +8V from Bus
and pin 2 = CS = CHIP SELECT = Enable Chip (TTL)
I am unsure about the voltage is right
The datasheet tells TTL
If it was a problem then I suspect a broken chip but it is still working.
(running for 1 day now)

1 thing to watch out for!!! REMOVE Battery’s before sending 8V to the device
The battery’s will burn out WATCH OUT (From experience )

[martijnspaan]

Hello Roel,

I tried several boards with your directions and the original one. I can't get it to work. I tried for weeks now. Don't know what to do or change anymore. I am using 2 different kind of pl2303 usb-ttl chips, nothing works. At the most, some rubbish caracters come back, but no status or whatever. So can you please help me with a board, sell me one or something. Is it possible to help me out with this. Can I buy one from you?



thank you very much

Martijn

[driesk]

Could someone post a wire diagram/schematic of a working setup. With a exact discription of the used components?
A photo would be nice of course.
My goal is to find a way to open/close/stop multiple rv2900 's via a vera (z-wave) controller. It coud be that such is only possible via a arduino or raspberry.
At this moments i am waiting to receive the rv2900's from my contractor

[DomoRob]

Someone asked for a schematic.
In am cotrolling an AXA RV2900 from my Raspberry Pi.
I use a pl2300 USB to UART TTL module to interface with the lin-bus driver.
This is the schematic of a working setup.
It works well with the Python script of kabelmanroel.

Schematic of the lin-bus driver

AxaSchematic.jpg (52.95 KiB) Viewed 32415 times

[driesk]

thank you very much, i was so close. just missed a resistor. I can confirm this scheme works well with putty on win7. Only problem i have is that some commands are lost. cable length is 4m. I use a cheap pl2303 from a chinese website.