Use a USB to Serial (DB-9) adapter instead of a USB to TTL UART adapter

I purchased a Bluetooth Module Wireless Transceiver from eBay. You can reprogram them with a different firmware using a USB to TTL UART adapter similar to this one.

My problem is I don't have a USB to TTL UART, but I do have a Sabrent SBT-USC1K USB to Serial (DB-9) adapter. Does anyone have any suggestion on how I can wiring up the Bluetooth module using my USB to Serial adapter? Thanks in advance.

What about using my Arduino Uno (I have the original Uno) to do USB to Serial? I remember reading you could, but I can't find any tutorials. Also on the USB Serial Light Adapter website it says "It features an Atmega8U2 programmed as a USB-to-serial converter, the same chip found on the Arduino Uno."

Can anyone confirm this?

JRMN: What about using my Arduino Uno (I have the original Uno) to do USB to Serial? I remember reading you could, but I can't find any tutorials.

Well, I can confirm part-way: I've done this with my Diecimila to program XBees before (see sites like http://www.kobakant.at/DIY/?p=163) or even to work with a TTL gps before I bought an FTDI cable.

The basic idea is to remove the ATmega chip itself and then wire directly to the transmit/receive pins.

Not sure if this will work with an Uno or not, but it can't hurt to try (I don't see why it wouldn't work)

I hope this helps,

Brad (KF7FER)

Thanks Brad, I think I will give it a shot. Now I just have to figure out how to do it on a Mac.

Just wanted to give an update. I removed the IC and wired the bluetooth module to my Arduino Uno and I have been able to communicate with it using ZTerm on my Mac. It should work for terminal too. Next step is to figure out how to update the firmware. Thanks again Brad for given me the push that I needed.

Bluetooth Module > Arduino Uno RX > RX TX > TX GND > GND VCC > 5V

JRMN: Just wanted to give an update. I removed the IC and wired the bluetooth module to my Arduino Uno and I have been able to communicate with it using ZTerm on my Mac. It should work for terminal too. Next step is to figure out how to update the firmware.

Great! Glad to hear it worked.

As far as upgrading the firmware goes, I think your board has the same module that Byron talks about in his blog (see http://byron76.blogspot.com/). Depending upon how your board is wired, it may be somewhat tricky hooking up the SPI connector.

I've actually got a pair of the same modules (from Deal Extreme) and need to do the same thing soon.

Hope this helps,

Brad.

Yeah it doesn't look like it's going to be easy. I will update the thread as I go, just in case someone else is looking to do the same thing.

What does changing the firmware gain? I think I followed all these links but can't find any information on what advantage a different firmware provides. Don't take this as a slight but rather that I'm genuinely curious. I see that you can issue AT commands; is that what you're trying to do?

By changing the firmware you basically gain more Bluetooth profiles, which will allow you to create different wireless devices, such as keyboards, mice and joysticks, etc. I think the reason why you haven’t seen any information on flashing another companies firmware on these cheap Bluetooth modules is because its illegal. They authors aren’t coming right out and saying it but you know their doing it.