i hope it’s ok to answer and have a few suggestions
it’s always hard to follow any ones hardware connection descriptions including my own once i re-read it.
this is a list of steps i take for about 30 years now
serial port issues … if u have a scope … use it on TxD and RxD … if u don’t, get one …
about US $ 150.-- worth every penny … can’t afford it … that’s hard … talk to a friend … get a used one … anything 20 MHz and up will do … 115 kBd has a pulse width of a bit less than 10 usec.
1st step … hook it up to a well known good communications device … like a USB to serial dongle from FTDI (FTDI … very good choice … a prolific based one a few years ago took 90% kernel time at 115kBd in win xp).
if you have 2 of them have them talk to each other with 2 different assigned com ports and same baud rate.
if you do RS232 level … the Tx pin has a neg voltage (-10V or so) when idle … The Rx pin usually floats at gnd level. so finally … both TxD and RxD pins should have a neg voltage on them once connected correctly as of TxD on one device goes to the RxD on the other device and vice versa. both connections have now each one a TxD pin producing the neg voltage.
now type an uppercase “U” and look at it at the scope you should see about 4 pulses of equal on and off times cause a “U” is ascii 0x55 → 01010101.
this gives u a good indication about the correctness of your desired baudrate setup on your embedded uart.
1000 baud is high times and low times are 1 / 1000 of a sec.
so back to your bluetooth issue … we still have them … so don’t feel too bad about it
hook your bluetooth serial device to a usb to serial adapter with a matching signal voltage level. FTDI sells 5 V and 3.3 V cables with the dongle part in the usb connector for about 25 bucks.
i’m not too thrilled about them, cause i blew the 2nd one i hooked up probably wrong in an embedded testing situation … now you have a brand new cable where you thought it’s gonna be ok and you trust it … wrong … sorry
i was so ticked that i revamped an old opto based usb to serial design i did years ago and made it 3.3 V and 5 V configurable … in the past i had to hand solder change 2 resistors 805 SMT to make the switch.
now i made it a product, but i’m not ready to sell it for another month or so … sorry again.
i have a few brand new pilot-run series devices … so if you really feel u need one, talk to me at efiHacks.com … but they peg out at 57600 bd.
2nd step … try to communicate with the bt module through a known good usb to serial adapter or another as good known source of ascii communication.
verify that these chars come out of your com source and arrive at the bt module … scope time
3rd step … do not have the bt module paired and try to see if you get an “OK” back after you sent “AT” …
once just send the “AT” and no and wait for 2 secs … that’s how the slave comm is on some bt modules
4th step … do the same with and or … now you should have gotten your "OK"s … if not … either your com baudrate is not the same as your bt module.
5th step … make sure the bt module get’s the "AT"s at the bt modules RxD pin … if not … hardware issue with your test setup.
… so now you sent your "AT"s and got your "OK"s … so we’re happy for now … but we’re not done yet
6th step … pair your bt module and make sure the os you use to communicate over bluetooth, “xp”, “win7” or whatever you use got all the way to identifying or assigning 2 com ports at the end … one outgoing and one incoming. use the outgoing one … with bluesoleil you have to wait to have one assigned at the end of the pairing process … do not use the 2 which get assigned upon installing bluesoleil … this was our experiences.
use a terminal emulator which works with the bluetooth … br@y++ did not properly
“termite” or hyperterminal did work fine … set the baudrate … “no handshake”, right from step one on.
connect with the terminal (select connect in the terminal app) and a flashing led on your bt module might get steady on or so … don’t know your bt module
only once you have a visual indication on your bt module, if it provides one, you can continue typing on both ends … the terminal connected to the bluetooth assigned com port and the other one connected to your ftdi usb to serial port.
you should hopefully get your typed messages across.
7th step … you should be able to see the serial chars on your scope on the RxD and TxD connection on your bt module
hope this helped
check out my 3 part blog related to “using bluetooth serial experiences” at http://www.efihacks.com/news/
good luck … i was hopefully not too detail-oriented and confusing