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veiledcavalier
Joined: 26 Feb 2006
Posts: 88
Helped: 2
Location: Alexandria-EGYPT
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 25 Jul 2006 1:35 wireless help |
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elsalam alykom,
plz i need help in wireless project ,
if any one knows how can i enter the password of a door from my mobile
WIRELESSLY plz tell me ,
thanks in advance
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cfant
Joined: 04 Apr 2001
Posts: 174
Helped: 18
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| 25 Jul 2006 1:45 Re: wireless help |
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| Your question is too general. Give more details.
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the_risk_master
Joined: 12 Aug 2005
Posts: 671
Helped: 59
Location: UE+MIT, Philippines, (14°N , 120°E )
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| 25 Jul 2006 3:17 Re: wireless help |
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good day!
yeah, please give more details of your project, probably a block diagram would do..
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veiledcavalier
Joined: 26 Feb 2006
Posts: 88
Helped: 2
Location: Alexandria-EGYPT
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| 25 Jul 2006 4:17 Re: wireless help |
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ok,
the project is "wireless security door lock"-----> it means that:
1) i have a door like one of my home this door will not open unless i enter
thecorrect password saved on the EEPROM of the µcontroller.
2) i am aiming to enter this password from the keypad of my mobile(GSM)
,so there is two solutions:
1st >> connecting the headphone cable to a DTMF ,so i will have a binary
output the problem is that i want to transfer this output to a reciever
then give it to the controller to compare.
OR
2nd>> from my mobile i can call my home telephone ,and so i will interface
the ID properity of the telephone then give it to the controller also
.... imagine the telephone is busy!!!!
this is the hole idea i hope it is clear i am waiting for help.
thanks for replies
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dragonkiss
Joined: 08 Mar 2006
Posts: 6
Helped: 1
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| 25 Jul 2006 14:43 wireless help |
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| i am thinking about your idea and have no answer now.and i can wait until anyone help you.
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BillRange
Joined: 17 Jun 2006
Posts: 3
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| 30 Jul 2006 18:47 Re: wireless help |
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-Use phone to Control a door
-1. 1Hardware Soultions:
>>1.1.1 U can use MT5087 as a DTMF transfer and use MT8870 as
a receiver;
>>1.1.2 U can use MT8880 as transfereceiver, and u must use
MCU such as 51 or PIC computer to control it;
>>1.1.3 Buy a MODEM to generate DTMF signals. always MODEM
is compatible with AT instructions, u can use Serial
port of 51/PC to communicate with them;
>>1.1.4 Buy GSM/CDMA MODEM. It should be compatible with
AT instructions;
>>1.1.5 If the signals don't cross the Telephone company,
u can modulate signals such as 100KHz or 110KHz as u
want by using NE555. Demodulate signals by using NE567;
====================================================
-2.1 How to know it is my signals when using DTMF signals:
>>2.1.1 Generally, in my country the voltage is 50v on
telephone line.
>>2.1.2 If telephone rings, the voltage is
twice times than usual, namely it will be 70-100v
when telephone rings. U can use voltage comparator IC
such as LM339 to judge if it rings.
>>2.1.3 Linking LM339 output to MCU pin, If u use 51
u can link it to INT0 pin;
>>2.1.4 If MCU get the ringing signals, then link the
telephone line to the DTMF decode IC or MODEM.
the linking methods is using relays to link or
separate the link between the input signal and DTMF
decode IC or MODEM;
>>2.1.5 If the control line share the same line as the
home line, MCU must delay to link the line;For example,
if the ringing times above than 6 times, we believe
user wanna open then door, or else we think our friends
call us for something, MCU don't need to open the doors;
For example:
Input Link --> Relays --> MODEM/MT88X0 --> MCU
|------>>--------LM339---------->>----------------|
=====================================================
-3.1 How to konw it is my signals when using GSM/CDMA?
>>3.1.1 U can send short message;
=====================================================
-4.1 How to Keep reliable in data transfering?
>>4.1.1 Make protocals between transfer and receiver. Eg.
we can create a data package for receiver to check if
datas can be utilized
For example:
Sending: SubMachineNo._DataLen_DataEncryption_CheckSum
Receiving: SubMachineNo._DataLen_DataEncryption_CheckSum
>>4.1.2 Overtime checking. If Main/Sub CPU finishs sending
a data package, but it doesn't get a reply in the fixed
time, we believe it is over time, then we began to send
again for 3 or 4 times. If it still can't get replies,
we believe the line maybe busy; If u use GSM/CDMA, the
problem does not exist;
=====================================================
-5.1 How to keep away others to control ur door?
>>5.1.1. If u always transfer the same package, others will
get the packets by MCU, and then he can send the same
datas to control the door of ur house; So the sending
datas on line must be encrypte.We can using following
methods to keep security For example:
-Main is theuser want to sending datas;
-Sub is a MCU that controls doors;
1. Main --> Sending random 8 byte datas;
2. Sub --> Using a function to calculate the 8 byte
datas, then send back to Main;
3. Main --> If get the the right reuslt, Main send
anthor random 8 byte datas and calculated
results to sub. This time Main is send out
open door commands;
4. Sub --> The get 8 byte datas and then calculates
the reuslts. If the calculated results is
the same as sending by Main, sub can
open the door;
Bill Range
2006.7.25
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