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geekhack Projects => Making Stuff Together! => Topic started by: phenotrophil100 on Mon, 05 October 2020, 11:59:55

Title: dt225 pinout
Post by: phenotrophil100 on Mon, 05 October 2020, 11:59:55
I bought dt225 serial version .
Please help me find out the protocol by which it works.
There are only 6 pins on the board for connecting the cable.
[attach=1]
[attach=2]
Title: Re: dt225 pinout
Post by: phenotrophil100 on Wed, 07 October 2020, 14:05:59
Taking a multimeter in my hands and ringing the db9 connector
with connectors on the other end of the wire, I found:
[attach=1]

So in the wire itself is broken (brown wire) - SHD .
Anyway i want to catch data with arduino.
Help please people who know solution.
Title: Re: dt225 pinout
Post by: suicidal_orange on Sun, 11 October 2020, 04:06:27
I may be wrong but SHD could mean shield, which wouldn't be connected to a pin.

Also moved this thread to MST! so hopefully more techy people will see it :)
Title: Re: dt225 pinout
Post by: phenotrophil100 on Sun, 11 October 2020, 11:14:56
Quote from: suicidal_orange on Sun, 11 October 2020, 04:06:27
I may be wrong but SHD could mean shield, which wouldn't be connected to a pin.

Also moved this thread to MST! so hopefully more techy people will see it :)
Ha-ha, thx for moving , idk in which branch should write this topic ;)
Title: Re: dt225 pinout
Post by: Tactile on Sun, 11 October 2020, 11:55:01
It was designed to plug into a standard RS232 (serial) port. The pinout has to be standard, also, else it wouldn't work. The pinout of a standard RS232 connector (http://www.usconverters.com/index.php?main_page=page&id=61) should work for you. This will tell you which pin carries the data from the trackball encoders.

The format of the data is the next problem. For that you really need an oscilloscope to see how the data flow changes when the ball rotation changes in direction or speed.
Title: Re: dt225 pinout
Post by: phenotrophil100 on Sun, 11 October 2020, 23:38:47
Quote from: Tactile on Sun, 11 October 2020, 11:55:01
It was designed to plug into a standard RS232 (serial) port. The pinout has to be standard, also, else it wouldn't work. The pinout of a standard RS232 connector (http://www.usconverters.com/index.php?main_page=page&id=61) should work for you. This will tell you which pin carries the data from the trackball encoders.

The format of the data is the next problem. For that you really need an oscilloscope to see how the data flow changes when the ball rotation changes in direction or speed.
Can't I just get by with a packet sniffer?
Title: Re: dt225 pinout
Post by: Tactile on Mon, 12 October 2020, 09:19:23
A packet sniffer expects the data to be in TCP/IP packets. I don't know how this trackball sends data & it might be in packets. If true, you're in. But if the trackball uses some other kind of communication - pulse width modulation, for instance - then the packet sniffer won't understand what it sees.
Title: Re: dt225 pinout
Post by: yui on Tue, 13 October 2020, 10:03:28
wireshark or putty may be able to help you with reading the data but from what i have read a usb to serial adapter should be all you need to use a serial mouse on windows, i have not tried myself so i dunno about linux but i would hazard a guess that it would work the same. as for the cable if only shield is broken it should not cause you too many issues, it is a fairly low speed device.