DTMF based robotic project

[digi_guy]

dtmf based projects

I am doing a project in which I have to control 3 servo motors and 2 DC motors on a mobile platform. It needs to be controlled in two modes. One is using a mobile phone on the robot which receives commands through DTMF tones from another mobile phone. The second one is from a computer. I want to use the same DTMF tone decoding circuit to control using the computer. I plan to use the serial port to send a byte to a microcontroller. Then generate DTMF tone using DTMF encoder according to the byte. Then transmit the tone wirelessly. I want to ask if I can use a FM transmitter and receiver pair for this? Will a home made FM tx-rx do?(I need only upto 20m range) And if yes then what are the problems I may face?
Also I am stuck with CM8870 IC. I am not getting any output while using the attached testing circuit.
Any other comments are also welcome. Thanks in advance.

 

[Noman Yousaf]

dtmf project

it must work
i have made it sevrel times.
u can do use, fm transmitter/reciever for dtmf transmition.
best dtmf generator ic is ht9200.
this is 8 pin serial generator.
u must use MCU to use it.
bye.

 

[pranam77]

dtmf controlled robot

I am doing a project in which I have to control 3 servo motors and 2 DC motors on a mobile platform. It needs to be controlled in two modes. One is using a mobile phone on the robot which receives commands through DTMF tones from another mobile phone. The second one is from a computer. I want to use the same DTMF tone decoding circuit to control using the computer. I plan to use the serial port to send a byte to a microcontroller. Then generate DTMF tone using DTMF encoder according to the byte. Then transmit the tone wirelessly. I want to ask if I can use a FM transmitter and receiver pair for this? Will a home made FM tx-rx do?(I need only upto 20m range) And if yes then what are the problems I may face?
Also I am stuck with CM8870 IC. I am not getting any output while using the attached testing circuit.
Any other comments are also welcome. Thanks in advance.

Contructed properly, even home made TX and RX shud work well and too DTMF can be transmitted using FM transmitters. The circuit attched is perfect and should work provided volatge is ok at the Vcc pin, the oscillator crystal is ok, and the IC is perfect. Vital point to be noted is that using a FM transmitter near a FM receiver circuit less than 1 meter between Tx and RX may affect the receiving sensitsivity of the Receiver as the transmitter signals tend to block the receivers front end..Good Luck

 

[digi_guy]

project topics and circuit based on robotic

Thanks a lot pranam77 and noman for your replies.

I tried the testing circuit a lot but got no results. Now I think i will try using another DTMF receiver IC (MT8880/MT8888/HT9170).

Thanks again.

Added after 55 minutes:

I have one more doubt. I am using a 6V, 4.5Ah SLA battery as voltage source.
It will have to drive upto 3 servos at a time. Is there any need of using separate power supply for the circuits?

 

[pranam77]

dtmf tone decoder using 8051

Hai digi_guy
Do note the vital points i have mentioned in the last post and check all. You may try replacing the DTMF decoder IC too. Volatge of 6 volts at 4.5Ah is more than sufficient for any digital circuits. A 5 volts regulator may be used to drop the voltage to 5 volts. But for the sake of motors, you have not specified any details and i coudnt guess. See what current is consumed when all the motors run and accordingly choose the supplly current. Good luck

 

[digi_guy]

dtmf based project

I am using two 6 V DC motors and three 4.8-6V Futaba S3003 servo motors.
The SLA battery when fully charged gives a voltage >6V. The circuits need 5V. How can I regulate the power supplies. Which IC can give 5V o/p with 6V i/p?

 

[nandhu015]

dtmf generator ic

Hai

As regulators need at least 2V higher than the o/p voltage it cant be used here

You can either use LDO or an simple zener with a resistor in series

Nandhu

 

[pranam77]

dtmf ic mt8888 tester

You may use Two 1N4007 diodes in series to the circuit which will drop the volatge to 4.8volts. or use one Diode to get 5.4 volts. Good luck.

 

[Noman Yousaf]

ht9170 projects

diodes are suitable choice but as i think u can use 6v batt. directly for driving survo motors.
i think it will work.
as u know batt. starts discharging even when connected so i think it will reach to 5v shortly.
mt8870 is exelent for decoder but i have used ht9200 it works i dont know about ht9170
bye

 

[sandeep_1905]

[Hi friends I am using CM8870 DTMF decoder I.C. but not getting output anyone
there whoes having the same problem and has a solution then please do reply
me or mail me it sandeepmanwani@ymail.com

 

[sahu]

[Hi friends I am using CM8870 DTMF decoder I.C. but not getting output anyone
there whoes having the same problem and has a solution then please do reply
me or mail me it sandeepmanwani(at)ymail.com

frstly post ur using ckt diagram & also clear , which ckt for encoder o\p using.
i hope ,i can help u ..........more more & more