SIM900 Customer Flash Loader

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Hi moyoumin, thanks for answer,

This is very bad news for our project...

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So how about SIM900? does it support FOTA?
 

Hi everybody,

Past days I have made a comprehensive read at all the documentation available for EAT developing and I have some basic questions that any of you that have already make the EAT work could easily answer.

1) I have compiled a basic EAT test application that send using the debug uart a string every 2 seconds using the API timer libraries. When I make the compilation, is has no errors, but allways appear 4 warnings of files that I haven't write and two no-optimization specified warnings also. Is it normal?...

2) For download the test code into a SIM900 and make it to work, is neccesary any special version of SIM900 firmware, or it works with anything?. I'm developing with DevIde 1.08, but the current SIM900 chip firmware where I'm planning to test it is 1137B09SIM900M64_ST.

3) I want to save a list of the required AT commands and other parameters in non-volatile memory (like flash), anyone knows which directive is used for telling this compiler to save a variable in code (flash) memory?. For example __flash, __code... For sure I'm trying to don't save the commands using the flash API because it require me to make a lot of flash writes at every system startup. I wan't to set this variables at compilation and programming time.

4) Talking about flash API, anyone knows if the flash writes and erases uses any kind of circular writting algorhytm along the entire available flash that uses all the flash memory once each time and maximize the flash life?...

Thanks a lot for all the comments, explanations and files uploaded. This thread is very very interesting for learning about SIM90X.

Regards,
Ignacio

;-);-);-)
 

Hello everyone
we have designed a low cost custom SIM900 development board. for last two days we are testing every AT command on this board. every command is responding (either result or error fro given respective commands), but we found that SIM VDD is always 0.00V. For which The module doesnt detecting the SIM. SIM card is oky and working with different modules. we have tried all dos mentioned steps here in the froum.. to make it get a SIM-VDD. but nothing is working. Screen shot is added of AT testing.

As you can see
1.Board is switched on.
2.Module ready but it respond +CPIN: NOT INSERTED
3.Basic AT commands respond OK.
4.Module restore to factory default.
5.Module went power down or switched off.
6.Again module powered up.
7.Again Module ready but it respond +CPIN: NOT INSERTED

During this process Working SIM card was present in SIM socket.
SIM-VDD at pin30 of SIM900 Module is 0.00V during all the time.
We are using FT232R USB UART in FULL HANDSHAKING MODE for serial communication. Baud rate:115200

When we tried to reflash the SIM900 Module with we firmware 1137B09SIM900M64_ST . we got this error every time



Pls guides us. if any one familiar with this SIM-VDD issue.
 
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Hi cnd,

I'm not an experienced or expert using SIM900, but when I started with this module I had some issues, so I could give you some ideas.

a) SIM card not inserted issue. You should start checking the sim card interface in this order.
a.1) Check that the SIM900 pin number and sim card socket pins are the correct and right connected. (Design problem)
a.2) Check that VDD 220nF-100nF capacitor is mounted on the board. (Mounting problem)
a.3) Check that 22nF capacitor of SIMDATA is also mounted on the board. (Mounting problem)
a.4) Check that there is a short between the SIM900 pins and the sim card connector pins with a tester. (Soldering problem)

If all of the above items are checked and ok I don't know what could be happenning. Maybe another more experienced thread poster can help you...

b) Programming issue. Check the same process but using 115200bps instead of 1152000bps. This could be the reason why programming is falling.

Regards,
Ignacio

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Hi,

...I know that there is another thread available, but maybe this is more readed than the other one...

Has anyone of the exprecienced SIM900 users fixed or solved the issue that there is no option for auto powering-up the module when is supplied with a supply voltage?...

Isn't there any hardware or software solution aside using a small microcontroller for generate the powerkey signal after module power-up process?...

regards,
Ignacio
 
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    cnd

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Hello Ignacio

As you mentioned the possible condition we double check every steps and found circuit design, mounting and Values components are oky as per SIM900 Datasheet, der is no shot between pins. Also SIM900 datasheet has mentioned it support both 1.8V and 3.0V SIM and the SIM interface is powered from an internal regulator in the module. We have also SIM908 EVB and SIM900 EVB, when we check SIM-VDD voltage on respective module on SIM-VDD pin we found 2.85~2.88 V on simcard presence and 0.00V simcard absence. We did some rework previously using Hakko rework Blower at controlled temp of 350C on VBAT side as we found a soldering shot during mounting the module. But dat doesn't affect the performance of module as we can very well access the SIM module tro UART n AT commands. On the other hand SIM interface is just opposite side of VBAT interface, so we really dont think that rework has made any damages to SIM interface section. Even we getting 2.85V on VDD-EXT pin (external power output from SIM900 module). We really dont wht to test next. pls Guide us on this issue.

and we also try to refalsh the module by chaging the baud rate, result as previous.
TEST @ baud:115200


Test @ Baud:1152000


And Ignacio for your issue to control auto power up we have the solution. actually this solution is also mentioned on SIM900 datasheet. Simply use this CKT . You can also feed the signal from a MCU.Just give the pulse for 1 sec and release. I am sure this will work. For more detail to control powerkey refere the SIM900 datasheet Power On section.
 
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Hi cnd,

About sim card issue, if you have checked the module connections, layout, also that all the components are mounted and OK, I don't know what could be happening. Typical issues are related with missing components and wrong connections. Maybe if you have an oscilloscope you should try to see some pulses in the sim card data line just after you have powered on the module by powerkey sequence. Other way is to manufacture or test another similar module to totally discard SIM900 issue.

About the flash downloading error, I also don't know why is this happening. If I were you I would try with another module to discard a SIM900 issue.

Maybe there are some expererienced users that had similar issues before anb could tell you what is happenning and anything to try.

About the issue to control auto power up and your proposed solution, this is exactly what I don't want to do. I don't want to use an microcontroller to only startup the module once it is powered. I want that SIM900 powers up and starts running just after I connect power to the VBAT, and not after making the pwrkey sequence.

regards,
Ignacio
 


then just pull down the POWER KEY pin to GND or shot this pin to GND. and u will get what u want. as i hv used this connection previously . But i would also advice you not to use it for long term purpose ,as instant power up the module cud fry up it in som case as i hv experinced it before. i hv 5-6 dead sim900 modules in drawer. So use it but with own risk.. all d best.

Regards CND
 

Hello everyone,
Firstly, thank-you for the SIM900 dialog above. It has proven helpful to me.
I currently have a SIM900 ver 1137B07 firmware. The module is from Open electronics. I have a number of Arduino shield versions of the SIM900 as well.
Unfortunately I have written my code to take advantage of features in 1137B09 (not sure, 1137B08 may work as well) but unfortunately I can't update the FW in the Openelectronics module.
I have done this FW upgrade a few time on the Arduino shields without problems.
The Openelectronics module has an off-module TTL logic level converter - 2.8 to 5V & Im using an FT232 to run the module via USB. I have tried both main & debug ports on the module plus a wide range of baud rates (max 115200, min 9600).
Serial dialog with the module is ok. The FW upgrade fails a few seconds after module power-up, with a "Frame Error 12" (Im recounting this from memory, it may be frame error 10). Im using firmware loader v1.01. I see there is a new version - V1.10 but it does not appear to have a SIM900 option.

Does anyone have any suggestions to help resolve this?

Many thanks,

Refsmmat
 
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    sherazi

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Hello der.
Pls give some screen shot images of ur error report. it will make thing easier to get.
 

cnd said:
Hello der.
Pls give some screen shot images of ur error report. it will make thing easier to get.
Click to expand...

Thanks for the reply. Two images are attached. Using AT+IPR Ive tried the upgrade with the module baud rate set to 9600 & 115200 before the upgrade. I have read the module switches to 115200 when the bootloader is active.
I had not correctly reported the errors in my previous post. Per the images, case 1 (SIM900 set to 9600, Cust flash loader 9600) the error is Error 306. Case 2 (SIM900 set to 115200, Cust flash loader 115200) the error is Error 000.

Regards,
refsmmat
 

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Hi Refsmmat

You have to make sure that the pwrkey is shorted to ground throughout the entirety of the update process. I can't say for sure but this looks similar to the errors I used to get when I released the pwrkey too early (it was a long time ago).

 

HELLO refsmmat

it looks like we both are having exactly same error report while flashing the module. Check my post#247 in this thread I have also mentioned same error report. i am actually trying to fix this for last few days. I have tried almost all possible ways to debug it, but still no good result. in addition my module even does not detecting the SIM inserted.

Oky you can try one more thing which I today discovered in my circuit. As i m using full handshaking UART mode with FT232R and SIM900. I found that I made an mistake while designing the board layout i.e I just wrongly connect RTS & CTS lines from FT232 with SIM900. it just got swapped. I have made dis corrected in new design layout, but it will take me a week to get new board n test it. So as u mentioned on previous post that u are using FT232 for UART communication, so pls check if ur using theses two line correctly(if u r using FULL HANDSHAKING UART MODE). If u r using standard TTL UART (i.e RX, TX, GND) Then i dont think it will work to flash as i Hv already tried this on my module. I wud advice u to go for FULL handshaking UART mode.

Regards
CND

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Yah I have also experienced it.
 



Hi CND (& also chipseller) - the two points raised are things I have not tried.
My previous upgrade was done with an arduino SIM900 shield & it only required TXT/RXD. I assumed this for the upgrade of the SIM900 Open electronics module.
I will implement RTS - CTS handshaking this weekend & give it a try.

On the need to hold on the Power SW - I was not aware of this at all. I will try this also.
I will report back on any success/failure (or smoke).

Thanks again CND & chipseller.

Have a good weekend.

Best wishes,
Refsmmat
 

Hi,

i decided to upgrade Sim900 firmware to have DTMF...

Sim900 baud rate was 9600, but when i want to upgrade it, this error occurs

also I tried all baudrates... but failed!



how can i upgrade this dragon??
 

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for my project I have to upgrade Sim900D firmware to have some extra feature. Then I face a problem, some module occurs error when I tried to. finally I cant success with 2 module(out of 10), the rests module working fine.
 

benhaham

* I did several upgrades and as experience I can tell you the best way or at least that I do not give less errors is the option 460800 baud with the flash loader V1.01
 

andres90125 said:
benhaham

* I did several upgrades and as experience I can tell you the best way or at least that I do not give less errors is the option 460800 baud with the flash loader V1.01
Click to expand...

with 460800 i got 'Error during change baud rate'

any way else?
 

The speed setting of 115200, which is the default speed in the flashloader tool is the only one I ever got to work reliably, whatever the module baud rate is.

See also my comments above about the power switch input
behnam9856 said:
with 460800 i got 'Error during change baud rate'

any way else?
Click to expand...
 

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