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Electronics => Electronics => Topic started by: Tomas on March 02, 2009, 05:43:09 AM

Title: Ezurio BiSM 2 SMT bluetooth module connected to an Axon
Post by: Tomas on March 02, 2009, 05:43:09 AM: Hi. I just got my hands on a bism 2 smt module, and I want to connect it to the axon. I basically want it, in the beginning, to send rprintf over bluetooth to my computer, so I can read it straight off the hyperterminal.

Now what do I have to do to get this?

Is it as easy as just changing
Code: [Select]
rprintfInit(uart1SendByte);// initialize rprintf system and configure uart1 (USB) for rprintf
to
Code: [Select]
rprintfInit(uart0SendByte);
?

Here's the datasheet http://www.ezurio.com/files/00579.pdf (http://www.ezurio.com/files/00579.pdf)
Title: Re: Ezurio BiSM 2 SMT bluetooth module connected to an Axon
Post by: Admin on March 02, 2009, 08:43:56 AM: Lets say you plug it into UART0 . . . you just need to call this line and make sure you declare the correct baud rate before you do a rprintf.

Quote
rprintfInit(uart0SendByte);

You can do all of that in control.c without changing any other file.
Title: Re: Ezurio BiSM 2 SMT bluetooth module connected to an Axon
Post by: Tomas on March 02, 2009, 03:46:26 PM: How do I find out the com port of my bluetooth connection on my computer?

I tried going into device manager, and I checked out all of those. But I didnt find any com-port-settings or information in that place (on any of the bluetooth-modules atleast)
Title: Re: Ezurio BiSM 2 SMT bluetooth module connected to an Axon
Post by: MrWizard on March 02, 2009, 04:22:10 PM: If youre Bluetooth is installed correctly you have the option Standard Modem for Bluetooth connection or sometimes you have software to connect it to lets say COM5 or COM6 .(software of the bluetooth adapter)
Title: Re: Ezurio BiSM 2 SMT bluetooth module connected to an Axon
Post by: Admin on March 02, 2009, 07:40:20 PM: HyperTerminal autodetects ports . . . when you plug in Bluetooth, you'll see a new com port appear ;D
Title: Re: Ezurio BiSM 2 SMT bluetooth module connected to an Axon
Post by: Tomas on March 12, 2009, 06:10:38 AM: I've read through the datasheet on this module, and it seems its operating on 3.3 voltage logic (3.3v UART). Does that mean the axon's tx and rx lines wont fit this? They operate on 5 volts logic right?

Whats the easiest way to fix this?
Title: Re: Ezurio BiSM 2 SMT bluetooth module connected to an Axon
Post by: Admin on March 13, 2009, 06:40:12 AM: Quote from: Tomas on March 12, 2009, 06:10:38 AM
I've read through the datasheet on this module, and it seems its operating on 3.3 voltage logic (3.3v UART). Does that mean the axon's tx and rx lines wont fit this? They operate on 5 volts logic right?

Whats the easiest way to fix this?
Very second page of this transmitter:
Quote
Supply Voltage 3.3V – 7.0V

;D

The Axon UART can supply it any voltage, as it has protection resistors built in.
Title: Re: Ezurio BiSM 2 SMT bluetooth module connected to an Axon
Post by: Tomas on March 16, 2009, 08:00:58 AM: Yes, I think I understand that. But the logic of the circuit, can axon's uart change the voltage logic from 5.0 voltage to 3.3 voltage? Im not sure if Im using the correct words, the number 1 is a voltage around 5 and the number 0 is the voltage around 0, right? But the bluetooth module uses a voltage logic of 1 between 2.2 and 3.4 voltage :)
Title: Re: Ezurio BiSM 2 SMT bluetooth module connected to an Axon
Post by: Admin on March 16, 2009, 11:04:36 AM: Read the datasheet, does it say the max voltage the UART can handle?

If it explicitly says up to 3.4V, then you need to make a voltage divider. Basically just two simple resistors.

edit: made a dumb comment about a voltage divider, now corrected
Title: Re: Ezurio BiSM 2 SMT bluetooth module connected to an Axon
Post by: Tomas on March 17, 2009, 02:44:33 AM: Well we have made a voltage divider (used three resistors). But the signal was slightly off, with some rounded edges. Hopefully it wont matter :)