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Original question:

TUSB3410: Is there firmware for IrDA?

TUSB3410: TUSB3410 IrDA with Vishay TFBS4652 IrDA transceiver

user6319551
Prodigy 85 points
Part Number: TUSB3410

Hi,

I'm using IrDA Firmware from Malik Barton57

I tried to connect Vishay to TUSB3410 for IrDA communication.

However, due to the communication speed, IrDA reception did not work well.

  • Fail 9600/19200bps
  • OK 38400/57600/115200bps

I have two question.

  1. Is there a way to get it well using the Vishay TFBS4652?
  2. Please tell me the reception specifications of TUSB3410 in IrDA mode.

Best regards,

  • 0
    TI__Guru 64326 points

    Hi,

    Unfortunately we do not have much support for this FW. Form your description I ma not sure that TUSB3410 is the issue since only specific baud rates do not work. This has not been reported by other customers. 

    IrDA operation is specified in the datasheet under section 5.3.4.3 IrDA Data Mode.

  • 0 in reply to Malik Barton57
    Prodigy 85 points

    I understand that much support for this FW is not available. But please let us know if you know anything.

    Let me give you a more detailed explanation.

    What doesn't work is the Rx side, and the TUSB3410 Rx works as follows on the 9600/19200bps

    * The echo back from the IrDA transceiver can be received correctly. (It is a 3/16 width pulse of bit)

    * The TUSB3410 may or may not be able to receive the signal received from the infrared by the IrDA transceiver. (It is a fixed width pulse of about 2us)

    According to the IrDA standard, the pulse width between 2.4k and 115.2k is 1.41us or more.

    However, isn't the pulse width required by TUSB3410 different from the IrDA standard value? I thought.

    Unfortunately, I didn't know the detailed timing specifications for the IrDA pulse width required by TUSB3410.

    If you don't have any more information, could you give us some information on IrDA transceivers that have been proven in the past in combination with the TUSB3410?

    PS: Would you tell me the difference between the two FWs I received? (umpe3410/umpf3410)

    Best regards,

  • 0 in reply to user6319551
    TI__Guru 64326 points

    Hi,

    Unfortunately this I do not have any additional information on other IrDA transceivers used by other customers. 

    They are the same function but slightly different functions. umpe3410 is meant to be used with a EEPROM and umpf3410 is meant to be downloaded through USB.

  • 0 in reply to Malik Barton57
    TI__Guru 64326 points

    Hi,

    Out of curiosity were you able to see proper operation at 9600/19200bps? If so could you post any steps you took to get it working?

    It could be useful to other in the future, Thanks!

  • 0 in reply to Malik Barton57
    Prodigy 85 points

    Hi,

    Using a monostable multivibrator, I extended the IrDA transceiver 2us-width pulse to 19us, which corresponds to 3/16 bit time of 9600bps, and I could receive at 9600bps.

    After all, TUSB3410 did not seem to accept the IrDA standard pulse of "min 1.4uS regardless of bps".

    However, its pulse width is too long to be used at 115.2 kbps.

    It was possible as an experiment to adjust the pulse width and make both communication at 9600bps and 115.2kbps, but both deviate from the 3/16 width. And I'm in trouble because I don't know the margin of pulse width that TUSB3410 can accept.

    Also, even if I try to make the pulse width switchable, there is no way to electrically know the set bps information, which is a problem.

    Now I'm planning to switch the pulse width using DTR or RTS while carefully checking the TUSB3410 margin by experiment. However, it may be difficult to use DTR and RTS because the host software needs to be changed.

    If you have any advice, please let me know.

    Best Regards,

  • 0 in reply to user6319551
    TI__Guru 64326 points

    Hi,

    Unfortunately I was not able to find any additional information here.