Ok, the title is a little vague. Here’s exactly what I want to do:
For less then a good new bluetooth keyboard (i.e. for <$80) I would like to wire up one of these sparkfun bluetooth devices to an (old) palm pilot compatible RS232 like portable keyboard and start typing into may iPod Touch. (It follows such a solution should work for an iPhone, iPad or Mac.)
(In case you were wondering, I did post to the end of a year old thread regarding the same subject. But, after reading it, thought I should spell out what I want to do / avoid leading people down the wrong path.)
But I am confused as to what I need and what is offered by these devices. Obviously, I don’t want support or hardware for, say, stereo music (A2DP??). But do want HID support such that my keyboard will work - or do I? I ask because there is also this bluetooth SPP feature which sounds like it could pass keyboard data. However, I am thinking SPP is more for supporting a wireless RS232 feature. Specifically, I doubt the receiving device (the iPod Touch, iPhone, iPad or Mac) will expect or be able to use keyboard data arriving at it’s bluetooth interface in SPP form.
I am probably talking apples and oranges (mixing HID (probably a USB definition) with SPP (probably a bluetooth implementation of RS232)). Regardless, bluetooth devices like the Broadcom BCM2040 chip exist which, stretching the point, bridge the gap between bluetooth and HID.
What would be perfect would be something like picking up a sparkfun WRL-08497, adding a battery, connecting it to the output of one of my palm pilot keyboards and start typing into my iPod Touch.
I think it comes down to this. Does the “thing” you are trying to connect to… Or, more specifically, the “thing” you are trying to get a bluetooth keyboard connected to expect to see a HID (Human Interface Device) or a SPP (Serial Port Protocol) device???
From the “mouth (i.e. web page) of the Freedom Pro Bluetooth Keyboard”:
Key features:
HID Profile - Used for connecting to Symbian and Windows Mobile Smartphones. Can also be connected to many HID compatible devices which have keyboard support such as Playstations 3’s, Netbooks, Laptop’s and PC’s.
SPP Profile - Used for connecting to BlackBerry’s and Android based phones. (Note: Android drivers are currently under development).
Ahhhhh… they didn’t list the iPod Touch!
So, what I’m thinking … maybe, just maybe either of these two sparkfun offerings might work:
It appears both support bluetooth SPP. I have not a clue which is better. Perhaps the second ('cause it costs more??). And I looked all through the tutorials here at sparkfun.com. Not a word on SPP or HID. Actually, googling “site:microchip.com hid bluetooth” comes up with nada WRT sparkfun products. Yes, they’re hits, but most if not all are just talking about the Wii remote.
So, let’s here from people who know!
question one: What bluetooth protocol is used by the iPhone, iPod Touch and iPad.
question two: If the answer to the above is SPP, then which of the above two “dongles” would work best at bridging from an RS232 (probably 0-3V) ASCII signal to and iPod Touch?
These guys (sparkfun.com) are great and all. But for the 2 times I needed to drill down into the details of their products (this and a 30 pin iPod extender cable) they have not come through with any answers. (Or maybe there are so many posts here they don’t have the time.)
Since I started this thread I have found a cheap “thumb” blue tooth keyboard with a BCM2042 based module inside. I have not been able to find any specifications about this module - but assume I can backwards engineer the bare keyboard to module connections.
Yes, using this BroadCom bluetooth module would require either emulating a keyboard by reading then translating the RS232 output of the target keyboard to a switch matrix -or- ripping the target keyboard to shreds in hopes of putting it back together around this module.
Add to that, the target host (my iPod Touch) is of the wrong vintage to support a Bluetooth keyboard. I think it is a 2nd generation Touch. I’ve tested the BCM2042 based Bluetooth keyboard and sure enough it works on other newer Touches laying around here. It’s just those are not mine. That takes a bit of wind out of this project. Don’t you just hate Apple for stuff like this. Obviously if my Touch can do A2DP bluetooth and HFP bluetooth it would be a snap to support a HID bluetooth keyboard. But apparently Apple has turned that off in the software.
My assumption is that these SparkFun bluetooth products are SSP bluetooth devices. And that Apple does not support SSP bluetooth protocol because it opens up their products to too many (uncontrollable by Apple) possibilities and 3rd party devices. Please jump in and correct me if I’m wrong.
On the other hand, if your Bluetooth host is a RIM / Blackberry, you might have a chance the SSP Bluetooth modules will work. I understand that RIM / Blackberry devices, unlike Apple devices, do work with SSP Bluetooth keyboards. But do verify this if you are interested.
So, if anyone has tried one of these SparkFun bluetooth modules with a 3rd+ generation iPod Touch (or any Apple product that supports HID bluetooth keyboards) please tell us about it.