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How to connect PIC18LF4550 to BTM411 Bluetooth module

Hello Everyone,

I'm working on a project where I'm using the PIC18LF4550 to send and receive information to the PC via bluetooth. I am using the BTM411 module on my circuit and I will be using the BT211 bluetooth Adaptor on the PC.

I need to know how to connect the pins of the BTM411 module to the PIC18LF4550, as in what pin should be connected to the PIC18LF4550 and what pin should be connected to other things etc.

Please note, I will be connecting BTM411 in my own circuit not in a development kit or anything, so please tell me if I need any additional components or devices.

Please don't hesistate to ask if you need me to provide any more details.

Thanks

d-glitch

I assume you have the data sheet for the BTM411:

http://www.lairdtech.com/WorkArea/linkit.aspx?LinkIdentifier=id&ItemID=4293

The schematic on page 63 shows how the BTM411 is wired on the development board. You can copy the the power and ground connections. You have a choice of UART of SPI for the data interface. The PIC can accommodate either one.

SPI is probably the better choice. If the BTM411 is the only SPI device, you can tie the Chip Select HIGH and deal with the 3-wire interface.

The data sheet should tell you how to terminate unused pins.

adkry

ASKER

Hello d-glitch, and thanks so much for your great feedback. A friend of mine had a look and told me that SPI is used for audio codec thing, i.e. UART is the only interface that can be used to interface with the bluetooth module.

I did read the manual thoroughly, but I'm using this module on my board so I believe there would be difference than from the case of the development board.

adkry

ASKER

ok I connected it in that way

The connections I need between the BTM411 and the PIC18LF4550 are as follows:

UART_CTS - Tells the bluetooth module that the PIC is ready - connected to any input/output pin in the microcontroller.
UART_RXD - Bluetooth module data input - connected to microcontroller UART TX pin.
UART_RTS - Bluetooth module uses this to indicate if it's ready or not - connected to any input/output pin in the microcontroller.
UART_TXD - Bluetooth module data output - connected to microcontroller UART RX pin
VDD_USB - connected to VCC = 3.3V
VDD_IO - connected to VCC = 3.3V
VDD_IN - connected to VCC = 3.3V
RESET - Used to reset the bluetooth module - connected to any input/output pin in the microcontroller.

any comments/suggestions on that ?

Also,
Does RTS indicate the status of the modem, and is the RTS/CTS logic active-high?

Which handshake mechanism has to be used: RTS/CTS or DTR/DSR?

How do I code the microcontroller (using C language) to send/receive data through the BTM411 ?

ASKER CERTIFIED SOLUTION

d-glitch

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