sim900 GPS模块使用问题，现象：不稳定

只看该作者 · 2013-1-17 20:47

各位兄弟，我公司现在用 sim900 GPS模块开发一款产品，主要是发彩信（同时向某个特定的邮箱以及手机发送），彩信内容是图片，图片大小在50k byte
目前的问题是产品不够稳定，主要表现在： AT+CMMSSEND 这个命令上。
正常情况下，mcu 向 sim900 发送 AT+CMMSSEND 这个命令后等待大约一分钟 sim900 就会有一个ok 的响应；
但是有时（大约10%的几率），始终没有ok 的响应，同时也没有任何的响应。

sim 卡我用的是移动的，信号质量我也查过，基本上都大于20.

所以感觉很奇怪，为什么会失败，请指教！

如果没有响应，我会等10分钟，然后会再发一次，基本上再发一次还是会出现同样的现象

只看该作者 · 2013-1-17 20:59

Passed GSM init
Cam reset in 38400!
Cam reset ok!
Cam set Baud:115200bps
Cam set 320*240 ok!
Cam set compression!
Cam stop photo ok!
Passed Cam init
Passed Timer
Update the tel
This is SIM900_MMS_CAM project!
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
+CMTI: "SM",1
$AT+CMGF=1

OK
AT+CMGR=1

+CMGR: "REC UNREAD","139********","","12/11/17,17:45:21+32"
62CD7167

OK
AT+CMGF=1

OK
AT+CMGR=1

+CMGR: "REC READ","***********","","12/11/17,17:45:21+32"
62CD7167

OK
Begin take the first photo.$First take a photo.ok,sizes=%d
AT

OK
AT+CMMSINIT

OK
AT+CMMSCURL="mmsc.monternet.com"

OK
AT+CMMSCID=1

OK
AT+CMMSPROTO="10.0.0.172",80

OK
AT+SAPBR=3,1,"Contype","GPRS"

OK
AT+SAPBR=3,1,"APN","CMWAP"

OK
AT+SAPBR=1,1

OK
AT+CMMSEDIT=1

OK
$Begin trans picture.
AT+CMMSDOWN="PIC",9804,5300

CONNECT
9804Cam_ReadPicData!

OK
picture transmit ok.
Stop taking photos.
Take photos again.
$Begin trans picture.
AT+CMMSDOWN="PIC",12532,5300

CONNECT
12532Cam_ReadPicData!

OK
picture transmit ok.
Stop taking photos.
Take photos again.
$Begin trans picture.
AT+CMMSDOWN="PIC",12836,5300

CONNECT
12836Cam_ReadPicData!

OK
picture transmit ok.
Stop taking photos.
Take photos again.
$Begin trans picture.
AT+CMMSDOWN="PIC",12148,5300

CONNECT
12148Cam_ReadPicData!

OK
picture transmit ok.
$AT+CMMSDOWN="TITLE",7,5000

CONNECT
Find the title' CONNECT

OK
pass title ok
AT+CMMSRECP="***********" // 一个电话，我隐掉了

OK
AT+CMMSSENDCFG=6,3,0,0,2,4

OK
Send！
$AT+CMMSVIEW

+CMMSVIEW: 2,"","139********","","","2000-01-01,00:01:42","4300610074006300680065006400",47496
1,"image0.jpg",7,9804
2,"image1.jpg",7,12532
3,"image2.jpg",7,12836
4,"image3.jpg",7,12148

OK
$$$AT+CMMSSEND