Create a new 2 wire(Telephone line) intercom station. (Normaly connected to FXS/ATA BOX)
Using Some AVR (Connect to external chip see below)
Code in some X languange. (Maybe C/Forth or other)
Power from Telephone line or and alt. Separate power.
Program input/output by, JTAG or and Serial interface (RS232/USB or other) or Throw DTMF Signal.
Detecetion of CALLERID throw incoming call, Set CALLERID when dial out.
Life messange test, CALLERID (special callerid) FXS dial to the pcb, pcb will answering, sending DTMF signal back
FXS Hangup. (Hook on).
Output, Shall be done by incomeing DTMF (Programable , function stored at eeprom or and Flash).
Input shall do Callout (Programable , function stored at eeprom or and flash).
Upgrade function of firmware in the pcb, Throw jtag or simular.
Other chip than CS6422 or and SM8223A or made some of directly into the AVR (Could be ok as well).
Function for the PCB ARE:
Ring, tip, Callerid (read and set)
Different type of callerid (Depends of country).
Input output Detection.
Echo canceling, Noise reduction.
Amplify Incomeing audio out to Speaker (If needed)
Life message test. Initated from fxs or and PCB. (every 1 hour to 72 hour)
Upgradeable software from jtag or simulary.
Adjustble Microphone db level and adjustble db level out to speaker.
Size of jnt162, the Speaker and microphone should be connected at the PCB.
Lead stearing (1 least one, blinking with incomeing call(ringing), Outgoing call ringing,(Fixed at ongoing call)).
24VDC power input. (As extra power if needed.)
Make Schema, or and 2-5 test pcb boards.
Create software, from specifications
(The test will be made by us, at Stockholm / Sweden).
1. AVR xxx
2. CS6422 full duplex speaker,
3. Maybe SM8223A for TIP/RING.
4. 4 input, Generate call or hangup
5. 1 relay out. 50v/1A.
6. 2 Output Open collector or other.
7. Maybe external Aplifier 2W for speaker 4-8 ohm.
8. Input , active low by ground. or and active high, (Some input detection needed).
9. Maybe Realtime clock chip.
10. Maybe lcd i row (Show date / Time) "Take it from realtime chip.
11. Speaker and microphone should be fitted directly in PCB, See picture.
Brg /Richard Dahlstrom R&D JNT AB