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Testing Device for DiSEqC-Switches using ATtiny13-20PI

This is my first AVR-project on this page. The DiSEqC-Tester allows to test DiSEqC-switches that uses 1.0 or 1.1 protocols. (DiSEqC-Switches with 2.0 and 2.1 protocol have backwards compatibility with 1.0 & 1.1 respectively and also may be tested). The device every second sends a DiSEqC-message that makes switch a DiSEqC-switch. Four LEDs are intended to show on/off state of ports of a DiSEqC-switch.


  • Features:
    • Power supply is 12VDC, max 200mA
    • Ports quantity to monitor – 4 (using internal LEDs)
    • Protocol support DiSEqC 1.0, DiSEqC 1.1 (Write Port Group Commands)
    • Two levels of 22kHz-tone – 650mV, 300mV
    • Switch frequency – 1Hz or 2Hz (depends on firmware version)
    • Commands indication via LED blinking and sound
    • Short circuit protection with sound indication

To test a DiSEqC-switch you must connect the red wire with “Receiver” input of the switch, blue wire with case, connect remaining yellow wires to ports of the switch in any order. Choose the protocol, tone-level and then turn power on. If the DiSEqC-switch is OK, a blue LED of the tester will be switching every second to another blue LED with short red LED blinking and beeping. Next photo and video shows how it looks.

The device every second generates a DiSEqC-message which has duration of 54ms. Each message consist from 4 bytes. Byte is 8 bit + 9-th odd bit. If protocol 1.0 is used, then device sends next commands-sequences: $E01038C0, $E01038C4, $E01038C8, $E01038CC, $E01038C0 and so later, else $E01039F0, $E01039F1, $E01039F2, $E01039F3, $E01039F0… These commands are so called “Write Port Group N0” (38h) and “Write Port Group N1” (39h) by DiSEqC-Protocol. The full description of DiSEqC-Protocol can be found at Eutelsat web site. For example, DiSEqC-Message $E01038C0 switches port “LNB1” of DiSEqC-Switch 1.0/2.0 into active state.

DiSEqC-Tester firmware v1.0a (protocols 1.0, 1.1; Frequency 1Hz, no pause after power on).

DiSEqC-Tester firmware v1.0b (protocols 1.0, 1.1; Frequency 2Hz, pause 0.5s after power on).

DiSEqC-Tester board in P-CAD 2004 format


For more detail: Testing Device for DiSEqC-Switches using ATtiny13-20PI

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