Electronic_V10
IMPORTANT! This schematic does not work without additional diodes! New schematic is coming soon...
Interfacing to V.10 is simpler to build because only a 5 volt power supply is needed.
The ULN2003 is the best choice to interface the different voltage levels and to build an adapter for less than 3€ (plus ESP).
Some teletypes have an optional V.10 interface like the TeKaDe FS200Z / FS220Z. The V.10 definition is near to V.24 (RS-232) with a voltage limit of -6...6V.
The hack with the diodes is to loop back typed characters to FS200 (local echo). With this change and duplex switch set to HDx the own typed text is printed in red and the text from the ESP is printed in black.
For FS200Z / FS220Z images see johanneskok.com
Status: partly tested
Note: TXD and RXD have to be NOT inverted in software. ONS have to be inverted
- ULN2003 (7 lines)
- ULN2803 (8 lines)
- 1N4007
- Any
| Name | Pin* | Description |
|---|---|---|
| D1 | 2 | Transmit data (teletype out) |
| D2 | 3 | Receive data (teletype in) |
| Betr.b. | 20 | If Telex is powered up, the "Beriebsbereit" (German for "ready for use") is set to +5V. |
| S2 | 4 | If LIN-button (equal to AT-button on FSG) is pressed S2 is set to +5V and line communication is active. |
| M2 | 5 | A rising edge (negative to positive) on M2 make a beep sound. Other dependencies to this pin are not known. |
| ARQ | 17 | This is used to request a saved message from teletype (not used in this project). |
| E* | 7, 9, 11, (12, 13, 14) | Ground |
*) Pins on 25 pin Sub-D male plug.
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