About:
This little chip is a bluetooth serial port with seemless integration into embedded devices as if you were using a standard rs232 null modem cable. They are great for short distance wireless projects that require
serial console access because you can get these things on eBay for under 10 bucks. The only hard part is figuring out how they work.
I've toyed around with one and I think I figured out the basics of wiring it up. In short, the whole device is inverted, so to connect it to an MCU/PIC directly, you would first have to set your serial parameters in the code to an inverted comms mode to compensate. If for some reason you wanted to connect this chip to a computers hardwired db9 serial port then you'd have no choice but to use a ttl converter chip like the MAX232.
By default it transmits and receives at 9600/8/N/1. No configuration needed; right out of the box, just power it up. You can bluetooth tether to this thing with a PC using a bluetooth suite, or with your Android device! To link it to your android, first power up the chip, discover bluetooth devices, pair to "Linvor", then enter "1234". To console to it, use an app like SENA BTerm, but dont forget to first tell the app to connect to it from the list of available BlueTooth devices. When powered up, the chip will Blink Red. Even after tethering it will continue to blink. As soon as something initializes the connection by trying to send/get data, the light will switch to solid red.
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Here is a single ASCII character directly out of the module.
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Here is the same char after piping it through the max232.
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Product Description:
Industrial serial port bluetooth, Drop-in replacement for wired serial connections, transparent usage. You can use it
simply for a serial port replacement to establish connection between MCU and GPS, PC to your embedded project and etc.
Computer and peripheral devices
GPS receiver
Industrial control
MCU projects
Default serail port setting : 9600 1
Pairing code : 1234
Running in slave role: Pair with BT dongle and master module
Usage
Coupled Mode: Two modules will establish communication automatically when powered.
PC hosted mode: Pair the module with bluetooth dongle directly as virtual serial.
Bluetooth protocal : Bluetooth Specification v2.0+EDR
Frequency : 2.4GHz ISM band
Modulation : GFSK(Gaussian Frequency Shift Keying)
Emission power : <=4dBm, Class 2
Sensitivity : <=-84dBm at 0.1% BER
Speed : Asynchronous: 2.1Mbps(Max) / 160 kbps, Synchronous: 1Mbps/1Mbps
Security : Authentication and encryption
Profiles : Bluetooth serial port
CSR chip : Bluetooth v2.0
Wave band : 2.4GHz-2.8GHz, ISM Band
Protocol : Bluetooth V2.0
Power Class : (+6dbm)
Reception sensitivity: -85dBm
Voltage : 3.3 (2.7V-4.2V)
Current : Paring - 35mA, Connected - 8mA
Temperature : -40~ +105 Degrees Celsius
User defined Baud rate : 4800, 9600, 19200, 38400, 57600, 115200, 230400,460800,921600 ,1382400.
Dimension : 26.9mm*13mm*2.2mm
Pin definition :
* PIO8 connects with LED cathodea with 470ohm series resistor in between. LED NEGATIVE connects to ground. It is used
to indicate the module state. After powered on, flashing intervals differ in different states.
* PIO9 is used to control LED indicating paring. It will be steady on when paring is successful.
* PIO11, module state switching pin. HIGH -> response to AT command; LOW or floating -> regular work status.
* With build-in reset circuit, reset is completed automatically after powered on.
* Steps to set to MASTER:
* Set PIO11 HIGH with a 10K resistor in between.
* Power on, module comes into AT Command Response Status
* Open HyperTerminal or other serial tool, set the baud rate 38400, 8 data bits, 1 stop bit, no parity bit, no Flow
Control
* Via serial port, send characters "AT + ROLE = 1 r n",if successful, return "OK r n", where r n is carriage return.
* Set PIO11 LOW, re-power, then in Master state, automatically search for slave module and connect.
