Might add Bluetooth to your ELM327 circuit. Using Serial to Bluetooth Adapters There are a few RS232 to Bluetooth converters on the market that can simply connect to a 9 pin RS232 connector, and provide Bluetooth capability. Two of these devices are the Firefly from Roving Networks (www.rovingnetworks.com) and the GBS301 from IOGEAR (www.iogear.
- The Bluetooth RS232 serial converter adapter work as the cable replacement. The distance is 100 meters. The products support the APP of Android. The Applications include: PDA, POS, receipt printer.
- The Firefly is a Bluetooth RS232 adapter. It attaches to a RS232 serial port making it a Bluetooth Class 1 wireless connection, capable of transmitting your serial data up to 100 meters (330 feet) away.
- You can use the Bluetooth Firefly with another Firefly in 'cable replacement mode' to make your RS232 cable wireless, or you can pair it with a BluePort XP (battery powered), FirePlug(USB serial adapter) or BluePlug (USB adapter). The Firefly Bluetooth serial adapter may also be paired with any other Bluetooth device that supports Bluetooth SPP.
This is a new Motion Computing J3400 tablet with factory installed Win7pro, and Motion driver updates to date. Factory installed internal CSR Bluetooth on USB bus using Microsoft stack.
All Bluetooth devices work properly after a fresh restart of Windows. The problem is only with resuming from sleep or hibernate.
Firefly Bluetooth Serial Adapter Download
It typically logs an error on every resume:
-----
Log Name: System
Source: BTHUSB
Date: 3/13/2010 1:16:43 PM
Event ID: 17
Task Category: None
Level: Error
Keywords: Classic
User: N/A
Computer: J3400
Description:
The local Bluetooth adapter has failed in an undetermined manner and will not be used. The driver has been unloaded.
-----
But that error does not prevent the Bluetooth keyboard, mouse, or audio devices from working, only the serial ports. ActiveSync on my WM5 phone says 'Connecting' forever, and serial terminal programs can't find external Bluetooth ports to open.
Device Manager and all other views of the Bluetooth system show everything is 'working properly'. Every driver I know to look for is loaded and working, so I don't have a clue what the error log is saying.
Bluetooth Serial Adapter Usb Power
Using Sysinternals Portmon, I've been able to see what may be an explanation. The details are captured in an Excel sheet, but I don't see a way to attach it here. To summarize, if you go to the Capture -> Ports menu in Portmon, it shows you the available COM ports and the BtModem designation associated with each one. After a fresh start of Windows, I see:
COM BtModem
9 5
12 6
14 7
11 2
13 0
8 3
15 1
10 4
('Firefly' in the following list is a Bluetooth to serial adapter.)
COM1 is free
COM2 is free
COM3 is GOBI QDLoader A008 usbvid_1410&pid_a008 (from registry)
COM4 is GOBI Diagnostics, USB 293A
COM5 is GOBI NMEA, USB 293A
COM6 is GOBI Modem, USB 293A
COM7 is Aten UC-232 in dock, right rear, USB 293C
COM8 is Bluetooth 'Outgoing' 'Generic Serial' for MotoQ
COM9 is Bluetooth 'Incoming' 'Mobile Device Center' for MotoQ
COM10 is Bluetooth for MotoQ DUN (in Devices and Printers) 'Standard modem over Bluetooth link #1' in DevMgr)
COM11 is Bluetooth for Firefly [outgoing, Realterm default] (in Devices and Printers)
COM12 is Bluetooth for Firefly [incoming, not used]
COM13 is Bluetooth 'Standard Serial' (for G1200 FTP?)
COM14 is Bluetooth 'Standard Serial' (for G1200 FTP?)
COM15 is Bluetooth for MotoQ DUN (in Devices and Printers) 'Standard modem over Bluetooth link #2' in DevMgr)
After sleep or hibernate, then resume, I see:
COM BtModem
9 5
12 6
14 7
11 2
13 0
8 3
15 1
10 4
9 13
12 14
14 15
11 10
13 8
8 11
15 9
10 12
Each COM port is listed twice, and it looks like the system has allocated a complete additional set of BtModem designations! Attempting to open a COM port accesses the new set of BtModem designations, and they never work.
Sometimes after resume from hibernation (I haven't established exactly when), only the higher-numbered set of BtModem designations appears. I've seen a sleep and wake cycle swap the list shown in Portmon between the high and low-numbered groups.
I've seen disabling and enabling the desired COM port in Device Manager make it work after resume and failure, but not always... When you do that, the affected port moves to the bottom of the list in Portmon, 'COM11:BthModem2' or 'COM11:BthModem10' depending on which group was active at the time.
If you could look in the (unfortunately not attached) Excel file, you'd see '(slow)' and '(fast)' designations. When you select a port in Portmon, it may enable the port instantly, put up an error dialog instantly, or wait for ten seconds or more and then put up the error dialog. While the problem is happening, there are many more ports that respond only after the long delay.
This seems to affect the opening of both the Bluetooth Settings -> COM Ports dialog and the Devices and Printers control panel. Both tend to open quickly immediately after a restart of Windows, but later both take a minute or more of watching the 'wait' cursor before filling in with data.
I see lots of complaints on the web about Devices and Printers being slow to open, running a progress bar in its address field for about the same amount of time it takes to brute-force search the entire system drive. I can't find anyone else connecting that to Bluetooth COM ports, but several people were complaining about it in relation to A2DP connections.
My luck with A2DP audio is better than with SPP. After a fresh start of Windows, it will automatically swap between a default headset when it is available, and speakers when the headset isn't on. After resume, I must manually select the headset audio device, since the default setting has reverted to speakers.
Sometimes if that fails, I can right click the disconnected BT audio device and choose Connect. But sometimes Windows has not recognized the headset is off, and Connect is grayed out. Properties -> Bluetooth 'Last connected' shows 'Currently connected' with the device switched off.
I'm not sure where to go from here... The work I bought this computer for requires using Bluetooth serial connections. My old computer with XP and a Widcomm stack uses them flawlessly, regardless of hibernate/sleep/resume. My XP media system with a Toshiba stack, which constantly alternates between sleep and resume, can also connect to any SPP port reliably. My phone connects to the same external serial ports with 100% confidence. The Microsoft stack on Win7 is clearly the problem.
Thankfully Windows 7 restarts much more quickly than any of the other devices!
Loren
If anyone wants to dig deeper, I'd be glad to send along my Excel data...