One weird bug on the XT75
May 30, 2009 — Florent ClairambaultYou might have faced this error with your X765 chip. The program crashes with this error :
1 2 3 | ^EXIT 00010000,02d6414253485f4c434c2c70726f6365647572655265636f72645f702d3e6e756d6265724f66526567697374657265645461736b73203c3d204d41585f4e4f5f524547495354455245445f5441534b53 ^SHUTDOWN |
If you convert the hex array to some text, that will give you :
1 | #ABSH_LCL,procedureRecord_p->numberOfRegisteredTasks <= MAX_NO_REGISTERED_TASKS |
Which might mean something to someone. But the point is, you won’t find any help. Mostly because it’s an uncommon error.
The error comes from the GPRS connection management. I had it when I was using a wrong APN (with the “AT^SJNET” command) to connect to a host. In my program, connection failed with a classic IOException (“Profile not found”) but 1 or 2 minutes later, the chip was ALWAYS crashed (with the “^EXIT” URC). So, the only solution I found to correct this problem was to automatically detect which APN is required.
This might also improve the ease of deployment of your programs. I like putting as much as possible auto-detection / auto-configuration code as possible. It takes a little time to write it but saves a lot of troubles (last minute configuration, human errors, human explanations, etc.).
The APN auto-detection code is like that :
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 | public static String AutoDetectApn( ATCommand atc ) { String[] apnList = { "\"gprs\",\"objcobytel.com\",\"\",\"\",\"88.191.11.20\",0", // Bouygues Telecom : "Objet communiquant" / "ObjetCo" / "ObjCo" "\"gprs\",\"m2minternet\",\"\",\"\",\"88.191.11.20\",0", "\"gprs\",\"internet-entreprise\",\"orange\",\"orange\",\"88.191.11.20\",0", "\"gprs\",\"a2bouygtel.com\",\"\",\"\",\"88.191.11.20\",0", "\"gprs\",\"b2bouygtel.com\",\"\",\"\",\"88.191.11.20\",0", "\"gprs\",\"ebouygtel.com\",\"\",\"\",\"88.191.11.20\",0", "\"gprs\",\"movistar.es\",\"movistar\",\"movistar\",\"88.191.11.20\",0", "\"gprs\",\"orange\",\"orange\",\"orange\",\"88.191.11.20\",0", "\"gprs\",\"orange.fr\",\"orange\",\"orange\",\"88.191.11.20\",0", "\"gprs\",\"websfr\",\"\",\"\",\"88.191.11.20\",0" }; synchronized (atc) { System.out.println( "Waiting 30s..." ); try { Thread.sleep( 30000 ); } catch (InterruptedException ex) { ex.printStackTrace(); } for (int i = 0; i < apnList.length; ++i) { try { String apn = apnList[i]; System.out.println( "Trying apn " + apn + "..." ); atc.send( "AT^SJNET=" + apn + "\r" ); SocketConnection conn = (SocketConnection) Connector.open( "socket://88.191.11.20:80" ); conn.close(); return apn; } catch (Exception ex) { System.out.println( "Failed : " + ex.getClass() + " : " + ex.getMessage() ); } } } // We couldn't find any APN return null; } |
And it is only launched when the SIM Card has been changed. To detect that, I have some simple code like this :
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 | { // APN auto-detection String imsi; synchronized (atc) { imsi = Common.getIMSI( atc ); } if (settings.confLastImsi.compareTo( imsi ) != 0) { System.out.println( "Sim card changed ! Auto-detecting APN..." ); synchronized (atc) { String apn = Common.AutoDetectApn( atc ); if (apn != null) reg.confAPN = apn; } settings.confLastImsi = imsi; // Whatever happens, we still need to save the current IMSI settings.Save(); } } |
Reference :
- The forum that helped me solve this problem
- Translating Hex to Text
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