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128 Threads found on sim908
Hello everyone, I am working on a project of GPS tracker and I decided to use sim908 which is a GSM/GPS/GPRS combo module having complete support of AT commands to control all functionalities. So I am planning to use microcontroller like 8051 with this module. My only target with this project is to send gps location thru gsm and gprs when
Hi I'm using sim908-C and have designed the hardware as described in its hardware design document. My issue is i'm not getting any voltage on SIM VDD and sim908-C is unable to find network i.e. relevant LED blink rate does not decrease. When I power up the module I see some mV on SIM VDD for very short time then it reduces to 0V. Please sugg
Can anybody recommend a development board that has a sim908 GPRS+GPS and a ARM MCU on the same board? I had been looking but couldn't find anything.
Hi, i need sim908 schematic and footprint in altium designer. please reply a link if available...:-| best regards...
Thanks Tonyolko, I already have that schematic (Evaluation Board sch). Could you share your schematic v57ali? Or could you send it to me, Thanks Hi Rod_O , I just read your post and think that maybe this schematic may give you an opinion
Hi, when I turn on sim908, It just send IIII???? and I dont receive anything more! also when I send AT commands, nothing happens! and Netlight LED shows that module is not registered in the network, 64ms on, 800ms off any one can help me plz... best regards
Hi all, After sim908 connecting to the server, I sent data with command AT+CIPSEND=. When it respond the prompt "> ", I enter data. Then wait for a long time, the modem respond "SEND OK". The timeout is quite long (about 8-12s), so i want to improve this problem. What command that I miss? or this is caused by server. Another q
Hi all, I buy a sim908,but pins 59(GSM-ANT) with 60(GND) are short circuit,while pin 79(GPS-ANT) is not connected to (GND),Does anyone have this problem?
I am using sim908 GPS_ANT pad to connection to an SMB connector from where it is connected to external(passive) GPS antenna. But sim908 is unable to track even a single satellite. I have used other GPS modules and signal loss due to impedance mismatch can cause degradation of signal resulting in less satellites being tracked. But in this case not a
Hi, I think the problem is the passive GPS antenna. sim908 must be used with active GPS antenna (which includes a LNA - low noise amplifier). I use a active patch antenna with build-in 28dB LNA.
Hi there, I am having a sim908 EVM board. I was able to send AT Commands and receive GPS data from a hyper terminal and a PIC24F. My next step is to send the GPS data to a backend server over a HTTP POST. I inserted a sim card in the EVM Board. I am using a normal power supply provided in the EVM kit. The VBAT LED is steady Blue, the GSM_NET Le
Hi all, I am using sim908 to get GPS. In my design, I connect GPS-VANT-IN(pin76) with VBAT pin(i use the active antenna). Everything run well. But today, I cann't not get GPS. I used mutilmeter to check voltage on GPS-ANT(pin 79), it present 0V(in common, it present approximate VBAT). That mean is the external antenna not power supply. I think
hi where can i find the datasheet of simcom sim908 with its pin outs.. i found the sim908-c pinouts but i need sim908 only. if any one has the information about sim908 please share it to me
Hi, everybody! I have a problem with sim908 module. i can't transmit or receive from sim908. I use max3232 3.3V buffer to Rs232 to PC. With same schematic I did it before. I can call, send message, add contact,GPS .... Now i can't commucation with sim908. Please help me i need it to finish my project. This is my schematic.77686
Hello all, My projects uses the sim908 module ... works fine with only one issue. The GPS stops responding after say 48 hurs of use, have to reset the system and it starts working again. any idea the GSM part works fine receives and sends SMS even when the GPS is down. any help is good thanx Raj
Also, if you have any sample schematic, project etc. of sim908 - Quad-Band GSM/GPRS & GPS....I will be very grateful if you share that with me. Can you tell me experiences about this module...pros and cons? Thanks!
I'm working on gps project based on sim908 module. But my sim908 module is not responding. Network LED connected to it also not working. I don't have any circuitry to communicate serially with PC. But when i Checked the status pin the voltage on it is always less than 2.3 volt. The VDD-EXT pin is also less than 2.3 volt. I hadn't used any circ
The sim908 GPS/GPRS module I'm developing with is having problems registering with my local towers. I can plug in it and communicate with the UART just fine. It doesn't seem to be a power issue as the module doens't power off or report low voltage. There is a GSM antenna attached, and the signal appears to be good. The NET LED is flashing for a
Hi everbody.Firstly I use sim908 module for my projet.I send AT command to sim908 but i didnt response.Later ı updated false firmware in sim908.i used SIM900 firmware update .Later Sım908 didnt work.GSM net led didnt blink again.How can i solve this problem.Please Help me .
Hi, I am planing to use Embedded AT comments of sim908 using sim908IDE software. But looks like sim908IDE software needs RVCT2.2 (ARM) compiler. Can anyone suggest where can i find this compiler and what would be the cost for the same. Thanks in advance. Jayamohan.M
Hi, I tried compiling a sample SMS project using sim908 IDE. I just want to make sure the compilation is fine and no any error occurred. I attached the screenshot of SIMIDE window. Can some one verify the screen shots and let me know, the things are fine or any compiler issue is there. Note: I yet to purchase the sim908 EVK. Regar
Hi, sim908 output altitude is in meters or dmeters ? Because where I am, is 7 meters approximately over the sea, and the output of sim908 is "68.382" ! Thank you !
please somebody have electronic circuit for sim908, ???
Hello, I am doing a project on vehicle tracking system. Please do suggest me which one is best is it sim548c module or sim908. I am thinking of buying one of its evaluation board kit of very low cost one. can u please suggest me where to buy the best and cheapest one.
Hello all, I know that sim908 has not LNA in the GPS section. What performance can be expected if I connect a passive ceramic patch antenna directly to the module? Any comments or experiences will be appreciated.
Hi Friends, I am new for sim908 ,i have stm32f103 microcontroller and USART1 of microcontroller is connected to sim908's microcontroller so i dont know how to interact with sim908 by stm32f103 i read AT COMMANDS but i cant interface with sim908 and unable to send AT COMMANDS please if anybody have the solution tell (...)
Hi Friends, I know without sim908 we can not send AT COMMANDS but i want to interact by microcontroller of stm32f103ve and in my application board UART OF stm32f103ve is connected to UART of sim908 (pin15 and pin16) i tried to send the command by UART TX PIN OF stm32f103ve but the problem is the status of RESETING The flag of STM32F103ve is done b
Hi Mohan, First let me state that I am not familiar with ST MCU's. With that said there are several issues with driving the POWERKEY from a MCU as follows. The POWERKEY should be driven by a open collector (drain) output of a external transistor. You can however drive it from a MCU pin if the pin can be configured for open drain output
Hi guys.i'm new in edaboard :) I'm in designing car AVL with sim908 module.I have a problem with power unit.The system powered with two power sources,external power from car and the other is internal 3.7 Li-Ion battery.The sim908 has a built-in battery charger(Very Cool!).I want to connect the battery to VBAT pin and external voltage from switchin
Hi. I used before already the sim900 and it worked fine. So I used nearly the same circuit for the sim908 but the netlight is on all the time and nothing happens. I checked already the powersupply and the ground and everything is fine. I get even an output from 0.35 Volt on the sim908 netlight output pin, but it never changes. Vbat and vbat2 ha
Hello everyone, In my senior design project, I need to create a device to find the location of my device and send an SMS to another cell phone. the command part of the design will be done by someone else, but the circuit design is my responsibility. I am using sim908-C for the task. I have the hardware design v1.01 document but I have some difficu
Hi friends, I am using sim908 for my application and i am capturing data from gps antenna and i want it in mode 0 , ......................................................... but i am not getting proper data that is gps data is lilke something 0,0.000000,0.000000,0.000000,2........................................... and so on...
I bought sim908 breakout ( ) but without the breakout board which has microcontroller. I have connected VCC (pin 17, 19), GND (pin 18, 20), TXD (pin 12) and RXD (pin 14). The power (ON/OFF) pin is 1 but how to invoke the module to turn on? Do I have to connect it to positive terminal or
After power on of sim908-C, The simcard_VCC should have 3V which is supplied to sim card. But it is 0V. I did not connect sim908-C(serially) with MCU so far. When i checked DTR and DCD, it's showing high(2.8V). But, DTR in sim908 modem is input pin. How can DTR have 2.8V without connecting to MCU?(DTR line is to be controlled by MCU (...)
I am currently working on a project using sim908 and I am facing issue with FTP command, I m trying to get files that is already on the server using "AT+FTPGET=1" but I get time out error " +FTPGET:1,64" can anyone help ? below the AT commands sequence AT+CSQ +CSQ: 15,0 OK AT+CREG? +CREG: 0,1 OK AT+CGATT? +CGATT: 1 OK A
HI friends, I am facing one problem communication port of sim908 is connected to xmc controller but sometimes the garbage data is received from uart of controller which is in connection with sim908 i also checked commands , string termination but still i am facing that problem some time . Please if anybody have the idea about how to solve thi
Post your circuit. It is related to Power. Did you try sending the command to sim908 from PC or from a microcontroller?
I' working on sim908 for a couple of days. The GPRS is working fine. At first the GPS module also worked good. But now when I power ON the GPS module and send "AT+CGPSRST=0" to start it in coldstart mode it gives me OK response but it didn't start in that mode. And the RST is still high. Maybe thats the reason I'm not getting my location. If a
HI , friends can anyone give me the full circuit diagram of sim908 please i am working on sim908 but i got it in unassembled form please can anyone help me??????????????????
Hi folks, I'm using the sim908 module with an Arduino shield. But, I don't know why, there is a wrong baudrate setting and the library, of Arduino, say: Trying to force the baud-rate to 9600 but don't work. 1 week ago it worked, now no, with the same sketch. I haven't change the baudrate with AT commands. So, there i
Im using the sim908 module to obtain GPRS connectivity and a PIC16f877A to obtain the image through UART from the TTL camera module. Image comes through UART and it is 512 bits. Can anyone please guide me, as to how to send this image through MMS to another place? no exact method.. just a guidance would be so much appreciated.
HI friends i am working on sim908 but i am facing problems related on the power the sim908 is not working plz help if any one know
Hello Everyone, I m using sim908 for a tracking device. Though sim908 has a GPS module, I still want to know the GSM co-ordinate of the device (As it can be found in SIM900 using AT CIPGSMLOC). Please suggest. - Rahul
I am using sim908. I need to get GPS data and send it over GPRS. Since my size is very small, I have to use smallest possible antenna. My GSM and GPRS are working fine, but for GPS I am struggling. I have on board AH316M157501 from Taiyo Yuden for GPS. Since this is chip antenna, I have kept GPS_VANT_IN and GPS_VANT_OUT floating. I am getting
Hi, guys. I am make boar read longgitude and lattitude from sim908 by PIC 16f887 and show on LCD. I simulated on Protues it ran ok, But when test on boar it didn't run. I don't understand why does it's run Please help thanks a lot!! This program on PIC: ============================================ #include<16f887.h> #fuses nowdt,put,hs,
Can it be that you posted the question without even reviewing the sim908 hardware design manual? 5.3 GPS-VANT-OUT and GPS-VANT-IN GPS-VANT-OUT is a 2.8V output for active external antenna, if the active external antenna works at 2.8V voltage supply domain, user can connect the GPS-VANT-OUT and GPS-VANT-IN directly. If the antenna?s pow
I want to connect more than one sim to my sim908 but I understand its not possible to directly do so. Instead I wish to control the SIM-VDD voltage keeping everything else (data,clk,i/o) the same. when I want to shift the network, I will shut down the sim908 and before I switch it back on using my microcontroller, I will apply the VDD to a diffe
Hi hemnath, I have checked the link you posted for learning sim908 for learning GSM/GPRS/GPS... , I think it is a good one It has got lots of modules and most interestingly two separated UART cable to connect GSM signal and GPS signal respectively to your PC. 92424 Give it a try and post all you learn for community to
I understand that sim908 does not accept active antennas. Can someone please recomend me a guidance circuit or a method to amplify weak GSM signal in a forest?
Im using a development board to communicate with the sim908. the dev board uses the IC SP23238EEA. My microcontroler is MSP430G2553 and I use MAX232 IC to convert the data to compatible format to be read by the dev board. The problem is the commands i send from the computer (baud 9600) are read successfully by the computer hyerterminal but no