Interface usage - Githubissues

stuartpittaway / WebastoWBUSInterface

Hardware circuit diagram for interfacing to the Webasto WBUS interface from a PC/Arduino

GNU General Public License v3.0

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Interface usage #1

Closed caspervanzoest closed 5 years ago

caspervanzoest commented 5 years ago

Nice work!

I've created this circuit using the example & descriptions, However, I have a few questions on the usage, since it is not (yet) working for me. I am trying to debug what is wrong.

Should te LED be always on or is it supposed to flash on either (or both?) TX / RX?
The RX and TX are from the USB serial device point of view, or from the wbus point of view? (i.e. Transmit from vbus is recieve on USB)
Are both 5V and 12V input voltages, or is either one of them output voltage?
If I put 5v on the TX pin, should the wbus pin have a 12v output?
if I put 12v on the Wbus pin, should the RX pin have 5v output?

I hope you can help me with answering the questions. Thanks in advance.

stuartpittaway commented 5 years ago

Hi, I've not used this circuit for a long time so I don't remember what it should do! I'll do still have the circuit board so I'll try and take a look tonight.

caspervanzoest commented 5 years ago

Thank you! I am looking forward to your answer.

stuartpittaway commented 5 years ago

Okay, have you built the breadboard circuit or your own following the diagram here?

https://github.com/stuartpittaway/WebastoWBUSInterface/blob/master/Webasto%20WBus%20Arduino%20Serial%20Interface%20mk7_schem.png

There are 3 connections to the heater - WBUS, +12V and GROUND.

There are 4 connections to the FTDI (or computer interface) +5V, GROUND and RX/TX

The LED should flash when data is sent or received.

The circuit is a basic 5v to 12v logic level shifter which converts two wire TX/RX into a single wire WBUS signal.

caspervanzoest commented 5 years ago

Sounds good, thanks! I guess I have used a wrong transistor in the circuit, since I did not have a correct one. I've ordered the specified ones today, so hopefully I can show you the result tomorrow.

Since I am building this for somebody else, and I do not have a Webasto device laying around, I assume I can test the hardware by putting 5v on the TX pin, and see if the wbus pin got a 12v output? As well as putting 12v on the w-bus, and seeing if the RX pin is 5v positive, right?

stuartpittaway commented 5 years ago

I assume I can test the hardware by putting 5v on the TX pin, and see if the wbus pin got a 12v output?

Yes, but you will need to supply a 12V power to the circuit as well as the 5V

caspervanzoest commented 5 years ago

I assume I can test the hardware by putting 5v on the TX pin, and see if the wbus pin got a 12v output?

Yes, but you will need to supply a 12V power to the circuit as well as the 5V

Got it! Thanks!