Asked — Edited

Bluetooth Swap Out


I see there is a T and an R along with plus and minus pins on the BlueTooth plug...

Is this a TTL level serial Trans/Receive or RS232 level or ???

What is the max acceptable baud? and what is the voltage on the + - pins?

thanks Dave


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Hey Putt Putt,

While I'm not DJ, I can answer a few questions about the Hardware, actually, we were discussing that very thing in this thread.

Communication is definitely TTL-level serial at 9600 baud. I don't know of anyone besides myself who has done tests at any higher than 9600. I did tests at 57600 baud with Synapse modules before and found it works but does decrease the range of communication. Don't get me wrong, with Synapse modules that was still like 200 feet indoor to outdoor. Be aware that this testing was just communication at that speed, I didn't have a chance to test servo timing or anything like that but I'm guessing that the higher baud would mess with the timing in DJ's code. I'd suggest that 9600 baud is the standard.

The "+" and "-" are +5V and GND, the Bluetooth module technically needs 3.3V to operate but the sweet module that DJ found has a voltage regulator on the carrier board so a higher voltage on the header was needed.

You looking at using some other form of serial communication besides bluetooth? If so, there's 3.3V power available from the onboard 3.3V regulator if you need it, that's where I tap off for powering my Synapse modules.


Fantastic...I will be trying X-Bee's, I'm a little familiar with them and have some on hand.

thanks again.



I have a question on the Synapse module. Does this require the purchase in pairs? One for computer and one on the EZ?


Hey Glickclik, yep you would need a pair of em'. Exactly like you said, one connected to the PC serailly (with a USB-TTL adapter) and one on the EZ-B with a breakout board. You would then have to configure the modules to be a transparent serial link at 9600, which is pretty straight forward as it is an example that comes with the Synapse Portal software.

Please note that if you are using an xbee/synapse module it's recommend that you have some level shifting on the Rx line of the module because the modules are rated for 3.3V and the EZ-B will transmit 5V signals to them. A resistor divider circuit usually works fine (2 resistors). See the old Xbee shield schematic for reference.


Thank you Skater and thans for the tip!


Hello all,

I'm new to all this, but I do have a related question. Given that it is possible to swap Bluetooth communication with XBee modules (ZigBee), is it safe to assume that the same applies to ZWave-compatible modules?

Many Thanks!



@skater_j10, the example looks like it's called "". Right? If so is the flowcontrol on or off?

EDIT-Nevermind I see it on page 31 of the SNAP Reference Manual.