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Serial Mouse

hasu@tmk edited this page Oct 4, 2024 · 7 revisions

Serial mouses won't work with 5V power and TTL and you will have to use RS-232 driver like MAX232.

TMK converter

NOTES

tested with Microsoft Green-eyed Mouse(DB-25) and Dell serial mouse(FCCID:DZLMMB14 DE-9).

Microsoft green-eyed mouse and Dell serial mouse need RS-232 line driver like MAX232. The mouses didn't work without line driver using 5V power/TTL.

Both mouses worked well with ADM232A. The Microsoft mouse seems to need high voltage and didn't work with SP3232E which outputs only +-6V at charge pump output.

Serial mouse pinouts

9 25    Mouse     DCE     DTE     MAX232        MCU
-----------------------------------------------------
1                 CD      CD
2  3    Data      TXD     RXD     ->            PD2
3  2    V-        RXD     TXD     <-
4 20    V+        DTR     DTR     V+(<-)
5       GND       GND     GND     GND           GND
6                 DSR     DSR
7  4    V+        CTS     RTS     V+(<-)
8                 RTS     CTS
9                 RI      RI
- --              ---     ---     VCC           VCC



,-----------.                               ,-----------.
\ 5 4 3 2 1 /                               \ 1 2 3 4 5 /
 \ 9 8 7 6 /                                 \ 6 7 8 9 /
  `-------'                                   `-------'
    female                                      male
    DCE                                         DTE

,---------------------------------------.  ,---------------------------------------.
\ 1  2  3  4  5  6  7  8  9 10 11 12 13 /  \ 13 12 11 10 9  8  7  6  5  4  3  2  1 /
 \ 14 15 16 17 18 19 20 21 22 23 24 25 /    \ 25 24 23 22 21 20 19 18 17 16 15 14 /
  `-----------------------------------'      `-----------------------------------'
    male                                       female
    DCE                                         DTE

DCE: Data Circuit Terminating Equipment(mouse side)
DTE: Data Terminal Equipment(converter side)

On Microsoft green-eyed mouse(DB-25):

DB-25 2  is connected to common(GND).
DB-25 20 is used as power source using zener diode to lower its voltage.
DB-25 4  is used to pull-up data line 3.
DB-25 3  sends mouse packet data.

On Dell serial mouse(DE-9):

DE-9 4 and 7 is used as power source.
DE-9 5 is connected to GND.
DE-9 3 is used to pull-down data line 2.
DE-9 4 is used to drive data line 2.
DE-9 2 sends mouse packet data.

Serial mouse protocol

Microsoft

1200bps, 7 databits, 1 stop-bit, 3 byte packet

Mousesystems

1200bps, 8 databits, 1 stop-bit, 5 byte packet

Sun mouse

1200 buard, 1-Start bit, 8-Data bits, No-Parity, 1-Stop bit

https://github.com/tmk/tmk_keyboard/wiki/Sun-Keyboard-Protocol#mouse-protocol

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