http://www.8051projects.net/ Learn to make simple microcontroller projects, pic, 8051, avr and arm projects. download 8051 projects, tutorials, libraries, sample codes. join the microcontroller discussion forum and ask doubts regarding electronics. the best source for 8051 over internet. en-gb 2008-12-01T23:31:38-08:00 contact@nospam.com hourly 1 2000-01-01T12:00+00:00 http://www.8051projects.net/forum-t8303.html 2008-12-01T23:31:38-08:00 i m using a maestro modem which supports both text and PDU mode. and i m interfacing it with PIC 917.i m able to send AT-commands using hyperterminal with the modem but when i communicate with the microcontroller, i m not able to get the response of AT-commands.i m sending a string like this:putc("AT \r\n");but it is not giving the required response.....it is not giving OK...what should i do????Plz help me on this.... http://www.8051projects.net/forum-t8303.html 2008-12-01T23:31:38-08:00 shyam u r using putc ?????is it meant to send char or string please check and reply!!! http://www.8051projects.net/forum-t8303.html 2008-12-01T23:31:38-08:00 monika i m displaying the output on LCD, for that i have written a code.....which u can see in the attachment.....plz tell me where i m wrong.....one more thing i want 2 know....if i will send msg, then can i write the code for text mode for reading the msg ( no need 4 PDU mode,bcoz my modem supports text mode 2) include.pdf http://www.8051projects.net/forum-t8303.html 2008-12-01T23:31:38-08:00 Ajay first do check what shyam said.There are few mistakes you might missed out. There is only carriage return while sending at command. So you don't need \nalso i think you have given space between at and \r which could be the point of error.to enable text mode do read your modem's manual carefully.instead of using putc use puts http://www.8051projects.net/forum-t8303.html 2008-12-01T23:31:38-08:00 monika i already did that. i compiled my code without /n. but result was same. No response of AT-command is comming. and there is no space b/w at and /r.i can't understand what is the problem with my code.....is there any mistake plz guide me... http://www.8051projects.net/forum-t8303.html 2008-12-01T23:31:38-08:00 shyam first of all please check if ur modem and controller can communicate properly..u have tested modem with the PC ...now test ur controler the same way see if u can reeive data from PIC(controller) to the hyperterminal.. http://www.8051projects.net/forum-t8303.html 2008-12-01T23:31:38-08:00 monika yes i have tested PIC with hyperterminal..and it is responding fine..problem arises when i interface modem with PIC.then there is no response on LCD.my hardware connections are ----for DB-9 connector-pins 1,4,6 are connected.pins 7 and 8 are connected.5 is ground.pin 2 is connected to TX of MAX and pin 3 is connected to RX.Plz check the connections and guide me accordingly.... http://www.8051projects.net/forum-t8303.html 2008-12-01T23:31:38-08:00 monika can anybody guide me what can can be the correct schematic for interfacing GSM modem with PIC microcontroller......i hv done the above mentioned connections bt these are not working when used with modem. these are working fine with hyperterminal. http://www.8051projects.net/forum-t8303.html 2008-12-01T23:31:38-08:00 Ajay make DTR and RTS pin of DB9 connector on board high.. and then try sending at commands.. http://www.8051projects.net/forum-t8303.html 2008-12-01T23:31:38-08:00 shyam does your maestro modem have a serial DB9 intervace or did it come with some special cable??? http://www.8051projects.net/forum-t8303.html 2008-12-01T23:31:38-08:00 Shailesh NAYAK Hi Monika, Could you give paste response of feve command asked?1) ATi32) AT+WOPEN=23)AT+WOPEN?Please also type ATE0 (it is ATEZERO) and then AT&W. so this will stop echo from MODEM first, then you can use microcontroller. I am sure it will solve your problem. also try to handle unsolicited responses from the modem. Please let us know if it is solve your problem or not. http://www.8051projects.net/forum-t8303.html 2008-12-01T23:31:38-08:00 monika yes my modem has DB9 connector.can you tell me what do you mean by making pins 4 and 7 high and what is the significance of it? http://www.8051projects.net/forum-t8303.html 2008-12-01T23:31:38-08:00 sashijoseph Making pins 4&7 high means just that......pull the pins high by connecting them to Vcc (preferably through 4.7k pullups).Pins 4 and 7 are used for flow control and probably are required to be high for comm. to take place.You can confirm by checking the voltage on the pins when connected to the PC. http://www.8051projects.net/forum-t8303.html 2008-12-01T23:31:38-08:00 Ajay can you tell us your basic application?and are you using only PIC?you can also make use of OpenAT to program your modem.regarding AT+WOPEN:This specific command allows to start, stop, delete and get information about thecurrent Open AT® embedded application.This command also allows to erase the Open AT® flash objects storage place, andconfigure the Application & Data (A&D) storage place size. Please refer to the OpenAT® development guides for more information.AT+WOPEN = 0 : stop applicationAT+WOPEN = 1 : Start applicationAT+WOPEN = 2 : Get open AT library versionAT+WOPEN = 3 : Erase flash objectsAT+WOPEN = 4 : Erace embedded applicationAT+WOPEN? : current state (either OpenAT application running or not)please do not use the commands unless you know what you are doing. http://www.8051projects.net/forum-t8303.html 2008-12-01T23:31:38-08:00 monika Shailesh NAYAK wrote ...Hi Monika, Could you give paste response of feve command asked?1) ATi32) AT+WOPEN=23)AT+WOPEN?Please also type ATE0 (it is ATEZERO) and then AT&W. so this will stop echo from MODEM first, then you can use microcontroller. I am sure it will solve your problem. also try to handle unsolicited responses from the modem. Please let us know if it is solve your problem or not.This is the response of the commands:ATi3657c09gg.Q24PL001 1956992 042407 11:29OKAT+WOPEN=2+WOPEN: 2,"AT v03.12","AT v03.12"OKwhat is the significance of these commands? http://www.8051projects.net/forum-t8303.html 2008-12-01T23:31:38-08:00 shyam the responses tell us the OS used i.e. 3.12and the firmware is 657cthese help in troubleshooting things!...