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planet69
Joined: 27 Jul 2006
Posts: 39
Helped: 1
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 21 Aug 2008 2:02 Sim300 POWER DOWN |
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Recently i've encountered a strange situation with sim300 module. After making a call and issuing an 'ATH' command, the module goes to POWER DOWN mode. It does not happen if i issue a second 'ATH' shortly after the first 'ATH' command.
What are the possible causes sim300 powers down automatically without sending AT+CPODN command?
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huys cobb
Joined: 10 Nov 2006
Posts: 63
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| 21 Aug 2008 4:57 Re: Sim300 |
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Did someone had .pdf file for picture http://www.utoolkit.com/gsm/
Thank's
Huys
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planet69
Joined: 27 Jul 2006
Posts: 39
Helped: 1
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| 29 Aug 2008 3:31 latest sim300 datasheets |
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| tags: sim300_atc_v2.01 |
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I've downloaded some sim300 module datasheets from the net. i believe these are the latest.
SIM300_ATC_V2.01
SIM300_HD_V4.01
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pisoiu
Joined: 31 Dec 2002
Posts: 891
Helped: 24
Location: Romania
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| 30 Aug 2008 1:12 Re: Sim300 POWER DOWN |
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| planet69 wrote: |
| What are the possible causes sim300 powers down automatically without sending AT+CPODN command? |
The module power down itself automatically if the power supply is under minimum requirements. Check the transmission spikes on the supply with a scope and see if they match the minimum requirements from datasheet. As far as I know, the module also power down itself if it's out of temperature range, but I think this is not your case.
/pisoiu
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srecko
Joined: 11 Oct 2007
Posts: 7
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| 01 Sep 2008 10:35 Re: Sim300 |
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| tags: sim300 not get data during call "call ready" at command send sms with sim300 save sms sim300 avr data call example sim300 |
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Hello, dear users of this forum. First, let me introduce myself.
My name is Srecko Lavric and people call me Lucky (=Srecko). My job is a teacher's assistant in electronic lab. Couple of years ago I started working on a project called Aqualink and we are close to starting a production. In this time I came across a lot of engineering problems and solutions too.
Currently I'm working around SIM300D GSM/GPRS module. The main benefit of this module is SMD variant. It can be easily soldered to the PCB without worrying about short circuits and bad solder joints. Also it has so big soldering pads, so you could solder some wires to it and use it on a breadbord.
Here are some important things, which might help someone to solve his problem, and maybe you will save an hour or two.
POWER SUPPLY
Powering GSM modules is very important, because they are very demanding peaces of equipment. Some of you didn't understand what is a transmitting burst. This is the borst of transmitting packets of data. This burst is present, when the module is registering to network, during voice call or when exchanging data in GPRS mode. During the burst the current spikes can be up to 2A, so your power supply must be capable of delivering this 2A during the peak power consumption.
Almost no regulator is capable of regulating the power supply in such manner, that the supply wouldn't fall a little during the burst. It is very important to keep this voltage difference as small as possible. It can be measured with an oscilloscope during a call. When starting a call the transmitter power is at maximum and is decreasing seconds later, when the cell acknowledges module that it can reduce power (in good signal conditions). The best would be digitizing oscilloscope, which can store the result for examination. In no case the voltage drop may exceed 350mV and the voltage may not fall under 3.5V. Please use 4V supply. Don't spare your capacitors. I use 2 capacitors 100uF/6.3V low ESR + 100uF tantalum + 1uF cheramic + 100nF cheramic. It works like a charm.
If your module powers off during TX burst, the power supply is the main reason. After this the module can not be auto restarted. It must be powered with PWRKEY. It is smart to monitor STATUS pin with your application. If it falls to logical 0, then the module is powered off. This pin needs 10k pulldown resistor to operate properly.
COMMUNICATION
Module's default baudrate is 115200bps. When the module powers up and registers the network, it releases an URC (unsolicited result code) "RDY". Newer software versions release "Call ready". Be careful of capital letters. This is issued at 115200.
If you don't want this communication speed (I don't know why not), then your application can issue "AT" command and wait for response. Try tis as long as you ger "AT" <CR> "OK" <CR>.
It is good to switch off the echoing of your commands. this is done with command "ATE0".
You can use only RX and TX pins to communicate with microcontroller, but you must keep in mind, that the length of what you receive can overflow your buffer and some data can be rewritten or truncated. I connected RTS and CTS together for this mode of operation.
Your firmare must be aware, that the module can send URC at any time. If you don't need this URC, you should at least cleas the RX buffer, if you are waiting for some other message.
SIM CARD
Very simple. Use 8 pin sim card holder with SIM presence switch. Connect all together as it must be (SIMCLK, SIMDTA, SIMRST, SIMVCC). Connect one end of SIM presence switch to GND directly, and other one to SIMPRE contact. This is all. If connected properly must work properly. Sometimes the contact on SIM holder or SIM card get dirty. They must be cleaned to work properly.
Another is "+CMS ERROR: 517". This means, that the SIM card is not ready. If you try listing the messages this may occure and sending will fail. You must pay attention to this error, since it can waste you a lot of time. For example, if sending an SMS message, this eror can occure. So better wait for SIM to get ready and then proceed. You can use AT+CMGL="ALL" for this and wait for "OK". Repeat this until you get rid of "+CMGS ERROR: 517".
MODULE RELIABILITY
This is only my oppinion. I used about 120 pcs of theese modules and all of them worked great without any problems and none of them died yet. They work fast and reliable. I'm more satesfied with SIM300D then wit SE (Wavecom) GS64.
I think this is enough for now. If you have any questions, please let me know. If you need some modules, I could offer you a peace or two.
If you have any experience with starting a GPRS communication between uC+SIM300D and UDP server, please give me a hint. I can't solve this puzzle yet. If you have any AT command example of what should be se up before usage of AT+CIPSEND, it will be highly appreciated.
If you came this far with reading, then thank you for your pacience and/or interest and best regards.
Srecko Lavric
P.S. I will publish this also in a new thread. Will se what will develope from this.
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ds18s20
Joined: 13 Jun 2006
Posts: 150
Helped: 2
Location: Bay Area
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| 02 Sep 2008 1:28 Re: Sim300 |
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| Silix wrote: |
I found a good web site with a working sample project :
http://www.utoolkit.com/gsm/ |
Silix,
This is really a good work man! Thanks for posting those gerbers. Now we will get some boards fabbed real cheap!
Thanks
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srecko
Joined: 11 Oct 2007
Posts: 7
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| 02 Sep 2008 8:52 Re: Sim300 |
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Hello.
If you need an original development board, it costs about US$ 100. This includes the board, GSM module, power supply, magnetic antenna and serial cable. I have one for my testing and it works great. If you are interested, I can give you an e-mail from my supplier from Funrock. By the way, this is only info. I don't get any provision from that.
Best regards,
Srecko
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Silix
Joined: 26 Apr 2008
Posts: 9
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Silix
Joined: 26 Apr 2008
Posts: 9
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ds18s20
Joined: 13 Jun 2006
Posts: 150
Helped: 2
Location: Bay Area
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| 12 Nov 2008 23:40 Re: Sim300 |
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| srecko wrote: |
If you need an original development board, it costs about US$ 100. This includes the board, GSM module, power supply, magnetic antenna and serial cable. I have one for my testing and it works great. If you are interested, I can give you an e-mail from my supplier from Funrock. By the way, this is only info. I don't get any provision from that.
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I paid $35 for the module, that means the eval board is sold for 100-35=65
Still about double what it cost to make one using silix' gerbers
Thanks silix!
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Konnie
Joined: 16 Feb 2007
Posts: 4
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| 13 Nov 2008 19:16 Re: Sim300 |
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Hi Srecko,
Funrock, HK price seems to be better than the local ones. Do they provide email/phone support also? How much is shipping cost and do i have to pay customs?
Please clarify.
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huys cobb
Joined: 10 Nov 2006
Posts: 63
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| 03 Dec 2008 7:48 Re: Sim300 |
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Hai...
I'm looking pcb picture of sim300c.The connectors different from sim300cz.
Best Regards
HUys
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zahak
Joined: 09 Dec 2008
Posts: 2
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| 09 Dec 2008 23:27 Re: Sim300 |
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| tags: sim300cz v3.04 send sms with sim300 |
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Hi Guyz,
I have SIM300CZ V3.04 and I have not any experience with this module.
I want to use this module with an AVR uC to send sms.
Would you please write me (or show me via picture) just pins that I need to use of this module?!
Your help is greatly appreciated in advance.
Regards,
Zahak
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