How to: RN52 programming and configuration (+video)

[Seth]

I'm not sure, but you might try swapping the RX and TX pins, and try connecting the CTS or RTS or DTS lines from FTDI to UART. I don't use the UART connector much myself, but what you're trying to accomplish is getting extremely close.

The BT1 and 2 leds will flash alternately when the module is ready to pair. It doesn't care that you're trying to change some settings.

BUT if the BT1 and 2 leds flash 3 times together and then stop, that means the RN52 is in DFU mode, which you don't want (unless the module needs upgraded to FW 1.16, but most RN52 already have that). You'll be able to see what version it's running soon when you are able to successfully send commands to it.

Thanks for being a trooper and sticking with it trying to get it to work! Most people would have given up a long time ago and cursed us for their troubles :)

[homerisback]

I have a friend's v3.2 back home for a software update as well as a RN52 settings update (to enable SID scroller), I'll follow my previously described procedure and let you know if I mixed or forgot sth...

UPDATE : Just did it and everything worked flawlessly with my Arduino Uno board :)
- RN52-PRG sketch uploaded in Arduino Uno board
- Atmega328 from BlueSAAB removed
- 3v3 and GND on FTDI header
- UART RX to Uno's pin 5 & UART TX to Uno's pin 6
- GPIO9 to GND
Using Arduino IDE software under Win 7.

[NeilR]

Here are pictures from multiple angles, front and back.  I hope your eagle eyes spot something I've missed!

[NeilR]

@Seth: Good, my BT1 and 2 LEDs are working properly.  I plan to stick with it until it works, thanks for developing this and for your help!

[NeilR]

Thanks @homerisback, I'll give this method that uses a separate Uno a try sometime over the next couple of days.

[NeilR]

It works!

I used @homerisback's Uno to UART method for the RN52.  I went from th e 3.3V on the Uno to the 3.3V on the FTDI and it only showed 2.9V at the connection marked 3.3V on the BlueSaab module, but when I pulled up the Serial Monitor in the Arduino IDE (set at 9600 and Both NL&CR), it showed the "RN53 programming mode" message.  It did not show "CMD", but when I entered D, it showed the current parameters.  After each of the commands to set the parameters for BlueSaab use, it showed AOK.  Disconnecting and reconnecting, then sending "D" showed the parameters were saved on the RN52.  Never did see the elusive "CMD".

I reinserted the 328 chip, attached the FTDI device and 12V at the CDC connector, then uploaded the SAAB-CDC sketch.  Then I plugged it into my 9-3 and tested it.  Works as described!

Thanks for all your help getting to this point, Seth, Karlis and homerisback!

[4pplet]

Anyone still have the code for this? The github link is unfortunately dead.

I've been using this project for a long time, but my unit recently died, so I'm trying to make a replacement unit.

[Karlis]

If you're looking for RN52-secific flashing/configuration firmware, yeah, that thing is long gone...

In legacy HW revisions (5.1 and earlier), RN52 configuration gets taken care of during power-on of module.

I haven't looked into this for a looong time, but here's a .hex file worth giving a try to. Use at your own risk. :)

BlueSaab_v5_1b.zip