In fact, as our Zauruses get older and less valuable, many of us might be more willing to take out the soldering iron and consider having a hack at them
Well, before trying to hack your Akita with the above:
- Verify, that Vin pins of regulators are really connected to VAC/Batt (un-stabilized voltage from battery or AC adapter (what gives more)).
- Verify, that reset is really wired (optional).
- The module is really ancient and probably out of production. Use of a modern pin compatible Bluetooth 2.1+EDR module shoud be possible. Newer modules don't need 1.8V and can work with auto reset. Not only Mitsumi produces pin compatible modules. At least Roving Networks do them as well.
- Depending on module version, you may consult the datasheet and check method of switching between modes and protocols (on the old Mitsumi it was provided probably by the two resistor to AIO pins). You need to activate UART modes, either ther H4 or BCSP. Sharp used H4, but if you don't plan to depend on Sharp software, BCSP may be a better option, as it allows deeper sleep modes (thanks to protocol for resending bits lost while sleeping). With BCSP you can also optionally repurpose two of four GPIO pins.
- Regulators mentioned above are not available in small quantities. You have to find any similar pin compatible IC. It must be a low-drop regulator. Cheap regulator need input 3V higher than input. Low drop regulators can work with 0.05V difference.
- Mentioned antenna is probably hard to get as well.
And this is valid in general:
- Buy only modules with HCI firmware. Modules with SPP firmware are ofter cheaper, but useful only as a wireless serial port. Without signing a NDA with CSR, you have only small chance to change the firmware. For the same reason, prefer cheaper ROM version of modules, because you will probably not be able to change firmware anyway.
- Consult datasheets and verify, that my guesses are correct!
- While ordering a part, check also letters after the IC number. They may mean incompatible variant or different firmware.
I have Terrier and this space is occupied by HDD, so I will not try it for sure, but I am trying to learn and finally design a small daughter board. (Now I am learning to work with gEDA.)