Need an engineer who is good on analog and digital circuit. I have a circuit almost done (file attached), so if an engineer can finish it, better. Else, a new circuit schematic will be also accepted.
This project consists of a telephone tester/ line simulator, that will work, basically, on an analog circuit. This is just an idea and can be modified. The digital part, with the microcontroller, will be used to control other stuff, llike LCD, ring, DTMF detection and generation, etc.
The tester wil be able to ring a phone, provide on-hook and off-hook voltage levels.
It will consist of a microcontroller (I am going to use a PIC microcontroller, but haven't decided which one yet), a DTMF decoder (MT8870 or whatever), a LCD, a RJ-11 jack, a polarity button, on-hook and off-hook led indicators, and a ring button. A DTMF transistor and RC circuit should be provided for DTMF PWM generation by the microcontroller to the phone and/ or caller ID.
Circuit will be placed on Proteus software for validation. Preference will be given for freelancer who hands in the job in that form.
Should have the following specifications:
on hook - 48VDC to 52VDC, but can be manually adjusted through a potentiometer.
off hook - 12VDC to 7VDC,
Ring - 90VAC, but can be lower (48VAC???)
Accept pulse dialing - leave a microcontroller input to count the dialed number by the microcontroller.
**NO CODE NEEDED!!
To make things easier, and I will ask for this, freelancer will hand in the chunks of schematic, so I can comprehend more easily and don't loose a lot of time. If freelancer wishes, the full schematic can be handed, but with all the appropriate annotations and explanations.
***MILESTONE RELEASE POLICY
What I need is the project to be done. Completely. Fully. In all it's extent. Period. I don't want half of a project, or a partial schematic, or partial something whatever. What I want is the complete project and this is what I am willing to get and, of course, pay for.
By this, I am creating one milestone only, to be released when all that I asked for up here is delivered. This is why I tried to be so criterious about each part. No exceptions will be made. PLEASE BID ONLY IF YOU ACCEPT THESE TERMS.