Apparently you need not the following steps anymore to get Bluetooth to work on the H3870. I would strongly advice you to check the Bluez mailing lists before following the steps listed. It has been a very long time since I worked on this and will not be able to help you much. link
- Vijay

(3rd March, 2003)

Compaq H3870 has an internal bluetooth radio for which support in linux was announced on 19th April, 2002. The radio is a CSR connected to a high-speed, memory-mapped UART that is visible as /dev/ttySB0. This document is an attempt to help you setup Bluez (available from to connect using this internal radio.

Steps to get Bluetooth running.
  1. If you ave not already done it, upgrade your kernel to 2.4.18-rmk3-hh4. Steps to upgrade your kernel is available in this document(will be up soon).I also have the compiled kernel and modules. Contact me if you want them.

  2. Get the latest Bluez tools and libraries from here. They are avaiable in the master package "task-bluez". So a simple
  3.     # ipkg update
        # ipkg install task-bluez
    should install the packages for you. For this to work, you must point your ipkg to pull packages from You can set ipkg to pull of from a particular URL by modifying /etc/ipkg.conf.

  4. The Bluetooth radio in H3870 runs by default in BCSP mode, while Bluez supports H4 mode. So the radio has to be configured to run H4 mode before it will work with Bluez. To do this, you need to use the "pskey" software that is available with the "task-bluez" package. This tool re-writes the firmware to work in H4. Please be careful when you do this!!! If you do something strange to your chip, it's not clear it can be fixed.

  5. Run pskey with the device as /dev/ttySB0 and speed at 230400
  6.     # pskey -b -d/dev/ttySB0 -s 230400

    The -b tells it to run using BCSP which the default in the chip.
        # pskey -b -d/dev/ttySB0 -s 230400
        Physical device :/dev/tts/0
        Speed :115200
        Use BCSP :YES
        <some more messages>

  7. Once you get this prompt, type
  8.     pskey>1f9 0003
        Key 01f9 length 1
        The new length of key 1f9 will be 1
        The new value will be 0003
        Type yes to write those values, anything else to cancel
        yes or no>yes
    This basically sets the key to H4. BCSP has a value of 0001 and H4 has value 0004.

  9. Finally type
  10.     pskey>191 01d8 00a8 00fa 0014 0004 0000 0004 001e 0064 000a
        Key 0191 length 10
        03b0 0006 00fa 0014 0004 0000 0004 001e 0064 000a
        The new length of key 191 will be 10
        The new value will be 01d8 00a8 00fa 0014 0004 0000 0004 001e 0064 000a
        Type yes to write those values, anything else to cancel
        yes or no>yes
    This sets the speed to 115200 and to use H4. For further details on what this means refer to [3].

  11. Now you are in business. Include the following lines to /etc/modules.conf:
  12.     alias tty-ldisc-15 hci_uart
        alias net-pf-31 bluez
        alias bt-proto-0 l2cap
        alias bt-proto-2 sco

  13. Type
  14.     # hciattach /dev/ttySB0 csr
    This will load the modules and start the device.

  15. Execute hcid
  16.     # hcid

  17. Execute hciconfig and get the local address.
  18.     # hciconfig hci0
    You can also use hcitool for setting up connections, to inquire, and to get the local address. Once you have another device also running, you can do l2ping etc. For more on Bluez, look at the [4].
This would not have been possible if not for the help of Porlin Kang, Andrew Christian and Sam J.Engström.

[1]. Andrew's post on the newsgroup.
[2]. Sam Engström's page on Bluetooth.
[3]. Fabrizio Gennari notes on the mailing list.
[4]. Bluez HowTo.