STN1110 v3.1.0 Firmware Update

For those of you that have ordered and use my OBDII module, a software update is available for the STN1110 chip that does all the OBDII protocol handling. The update has some bugfixes and feature additions. See the changelog below for details. All modules I’ll be shipping from this date on will come w/ the latest STN1110 firmware.

If you’d like to update your module, you need to have access to a PC with a Bluetooth adapter/dongle installed. A laptop would be preferable as you’ll need to power the STN1110 to update it (aka have it plugged into your vehicle).  Click “continue reading” for the update procedure!

Do the following to update your module:

1.) Install the module into your vehicle and make sure the ignition is off

2.) Wait until the flashing LED is flashing slowly, roughly turning on once a second (the LED will go from fast flash to slow flash roughly 30 seconds after plugging the module into your vehicle)

3.) Pair the module to your laptop/PC and type in the pairing code (1234 unless you changed it to something else)

4.) Make your Bluetooth software create a serial port (COM port) for the module. This process depends on your Bluetooth software running on something other than Windows 7. Windows 7 should automatically create a COM port for the OBDII module.

5.) Determine the COM port number that was created (if the software/Windows didn’t tell you) by doing:  XP/2000/98: Control Panel->Device Manager->Click plus sign next to “Ports”.  Win7: Control Panel->Hardware Tab->Device Manager Button->Click plus sign next to “Ports”.  Your newly created port should say something like “Bluetooth Communications Port COMx” where “x” is the COM port number that you’ll need for the updater.

6.) Download the STN1110 v3.1.0 installer here:

7.) Extract the files from the installer zip

8.) Run StnFirmwareUpdater.exe from the folder you extracted all the files to

9.) Select the COM Port number for the OBDII module you found in step 5 and then click the “Upload Firmware” button.  Do not remove the module from the vehicle, turn the ignition on, or unpair the module from the PC.  Ensure the PC is located close to the module to ensure a stable connection.

10.) The update should be able to connect to the STN1110 onboard the OBDII module and start the update.

11.) Once the update is complete, remove the module from the vehicle, reinsert it, and start using the module w/ the latest firmware.

12.) As with all software updates, there is a possibility of bricking the module.  However, the updater and the bootloader in the STN1110 make the possibility of this happening extremely slim.  If you feel this is too risky to do yourself, I’d be happy to update your module for free, you’d just need to cover the shipping costs. Or, you can safely stay at the current software version.

13.) I cannot assume any responsibility for any harm the software update could do to your module.  Again, while this risk is extremely small, this is a “perform at your own risk” procedure.

v3.1.0 – 2012/05/16

– NEW: STCMM (set CAN monitoring mode)
– NEW: STFA (enable automatic filtering mode)
– NEW: STP (set protocol)
– NEW: STPR (report current protocol number)
– NEW: STPRS (report current protocol string)
– NEW: STPO (open protocol)
– NEW: STPC (close protocol)
– NEW: STPTO (set OBD response timeout)
– NEW: STPCB (set automatic check byte calculation/checking)
– NEW: STVCAL [no param] (reset voltage calibration to factory defaults)
– NEW: ATCRA [no param] (set CAN hardware filters to defaults)
– NEW: ATCSM (set CAN silent monitoring)
– NEW: ATJHF (set J1939 header formatting)
– NEW: ATJTM (set J1939 response timeout multiplier)
– NEW: ATBD (compatibility only – NOP)
– NEW: Renamed filtering commands to fit the new naming convention (old ones still available, but deprecated)
– NEW: Renamed STPRBR to STPBRR (STPRBR still available, but deprecated)
– NEW: Implemented PP 11 (J1850 Break Signal monitor enable)
– NEW: Implemented PP 12 (PWM/VPW pin polarity setting)
– NEW: Implemented PP 21 (ATCSM default setting)
– NEW: Added ability to turn off J1850 CRC calculation and checking
– NEW: Implemented CAN ERROR detection during monitoring
– NEW: Added capability to receive invalid CAN frames (STCMM 2 only)
– NEW: STDIX (factory use only, extended device ID information)
– CHG: Implemented new default J1939 timeouts
– CHG: Added CAN transmitter “Bus Off” mode indication to ATCS command
– CHG: Changed ATST and PP 03 default to 0x19 (102 ms)
– CHG: Removed length limitation on custom keep alive messages (ATWM command)
– CHG: Removed 8-byte Tx data length limitation for J1850 protocols (ATAL only)
– CHG: Increased CAN FIFO size from 23 to 31 frames
– CHG: Increased UART Tx buffer size from 512 bytes to 1k
– CHG: STRSTNVM command now also resets the device
– CHG: ISO 5-baud init will now not complete initialization if the key byte validation fails
– CHG: Increased ISO feedback settling wait time from 10% to 33% of bit time
– CHG: Now all filtering commands turn off automatic filtering mode
– CHG: ATAL is now forced on, when CAN auto formatting is off (ATCAF 0)
– CHG: UART Rx now ignores LF characters for the purpose of cancelling a command (CR+LF EOL handling)
– CHG: OBD Rx LED now blinks for all received messages, inluding internally consummed CAN flow control messages and KWP2000 StartComm responses
– CHG: Now ISO key bytes will be reset to ‘–‘ if init fails or is canceled (ELM327 v1.4 behavior)
– CHG: Relaxed some J1850 PWM timing settings to work better with slightly non-compliant ECUs
– CHG: STFAPG command now accepts PGNs 4 to 6 characters long
– BUG: ATTA command was changing headers even if the protocol was already open
– BUG: KWP fast init was not properly using user-set headers
– BUG: With protocol A5 set, autodetect would potentially not work properly with non-default headers set
– BUG: CAN Rx would sometimes lockup the IC during busy CAN bus monitoring due to FIFO corruption
– BUG: – BUG: There could be erroneous – BUG: SRR bit was being incorrectly set when transmitting 29-bit CAN frames
– BUG: J1939 TP sessions would not time out if no CAN frames are coming in
– BUG: Entering monitoring mode would reset CAN settings to the protocol defaults
– BUG: Due to a race condition, heavy UART Tx traffic sometimes would generate FATAL ERROR 0x0101 [0x05, …]
– BUG: Sleep triggers were not working if ATMA on startup was enabled (PP 00), until ATMA was terminated
– BUG: Protocol would not get properly saved if ATSP set it to the same protocol that was autodetected or set via ATTP
– BUG: STIBR command would not correctly set baud rates above 32767 baud
– BUG: Actual default values for the PowerSave voltage triggers were different from those reported by the STSLCS command
– BUG: KWP2000 fast init did not work reliably with vehicles that have multiple ECUs responding to StartCommunication message
– BUG: SLEEP input polarity setting was being ignored
– BUG: PP 0B PWR_CTRL pin polarity setting was being ignored
– BUG: Some sleep triggers could glitch after about 24 days of continuous operation

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4 Responses to STN1110 v3.1.0 Firmware Update

  1. PaJa says:

    Hi Andy, festival your OBDII design still works fine. Did you notice v3.2.0 – 2012/09/19 FW upgrade for STN? Have you any experience with it?

    • Andy says:


      No I wasn’t aware of the update. For the last update, they emailed me to let me know it was out. I’ll have to do a post for the latest update. I don’t see any issues in updating to the latest firmware.


  2. PaJa says:

    Hi Andy,
    I just updated the firmware. The first attempt finished with error – Firmware upload error: Connection with device lost.
    The original FW has been deleted or broken probably, as I was not able to display data from the adapter. The second trial was, fortunately, successful without any settings change, I just reinserted the plug and started updater second time. The Updater complained, that “Valid firmware not present”, but the new FW has beed uploaded and after the reset I was able to establish the valid session with my Torque application.

    • Andy says:


      That’s probably good that you got the “invalid firmware” message after trying for the 3rd time. That means your 2nd attempt worked fine. From what I understand w/ their bootloader, you could totally trash the firmware, and the updater would be able to recover from that failure (your 1st attempt, followed by the 2nd attempt hehe). So even though the error message sounds bad, the intent is probably to disallow the user from reflashing the firmware countless times. I’m not sure what that accomplishes, but that’s the way it works.

      I am a bit surprised that the updater would program the new stuff w/o transferring the whole thing to the device first, but it’s possible there’s not enough free RAM on the device for such an operation.

      For others reading this, if you do want to update the firmware, you need to have your laptop as close as possible to the adapter to ensure a good, stable link.

      Glad the adapter update worked!


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