easy bluetooth

fatih

does anyone know the Uart Speed of the RBT-001.
Its default value is 9600bits/sec in manual but I am not sure whether its non-volatile registers are programmed or not by Parallax.
Since it is not possible to look its registers without knowing the Uart Speed I must learn this somehow.

thanks

Mike Green

The default UART setting is 9600 Baud. This means that the RBT-001 comes from the factory set to 9600 Baud. I don't think Parallax changes anything.

If the Easy Bluetooth doesn't respond to 9600 Baud commands, make sure that the polarity of the data is correct. The transmit and receive lines should idle at logic high (non-inverted).

fatih

I have two questions

1. In RBT001 manual, the byte order is defined. However the bit order is not defined. I mean there is no information to send most or leas sifnigicant bit of a byte first.
2. In RBT001 manual, RTC and CTs pins are defined as active low but there is no information about RX and Tx. Therefore I assumed that they are actice high(1->3.3V, 0->0V)
Does it matter the transmit and receive lines are high or low when they are idle. I mean if they are acvite and if I am looking for a start byte(i.e. h'02 or b'00000010) I just observe the line and look for a 0-1-0 transition in 9.6kHHz.

Mike Green

1) There is a "standard" for asynchronous serial data that defines the bit order. That's why it's not explicitly stated in the manual. Look here: en.wikipedia.org/wiki/Asynchronous_serial_communication.

2) Again, there is a standard involved based on RS232 (see: en.wikipedia.org/wiki/RS-232). The RBT-001, like most asynchronous serial devices, uses logic levels (3.3V / 0V) rather than RS232 voltage levels (-10V / + 10V) and is designed with the assumption that you would use something like a MAX232 to convert all the signal levels. The Rx and Tx signals would then idle at logic high.

fatih

thanks Mr.Green
but there is a big misunderstanding.
First of all I did not mention that I am trying to communicate with RBT001 with the serial port of my pc. In my design, I will connect an FPGA card to RBT001. Than I will communicate my FPGA with a bluetooth dongle which is connected to my PC. Since the output pins of FPGA gives 3.3V I am connecting RBT001 to FPGA without the regulator module.
Secondly, the communication between RBT001 and its HOST(FPGA card in my case) is not an RS232 communication and the wiki websites that you gave their links are totally irrelevant. Just have a look at page 22 of the manual of RBT001. There is nothing about start-bit, stop-bit, parity etc.
I asked the bit order because I know that in most of the applications the least significant bits are sent. However, in some protocols(like I2C) most significant bits are sent first.

I am still trying to guess the missing but important specifications in the manual which is not a well prepared one.