If you are looking for the thread for the new BTOA board with MS6511 sensor, please go here: https://www.rcgroups.com/forums/show....php?t=1959055

Updated January 29 2013.

The altimeter will prompt the Android device running F3K Master to read out your launch altitude as you come in and land nearby or catch the glider. It will also read out the max altitude if applicable and the battery voltage.

Based off the fantastic Open Altimeter V7 (http://www.openaltimeter.org - thanks Jony and Jan!) and modified by me to work with F3K Master (https://www.rcgroups.com/forums/show....php?t=1453871) and a bluetooth module (https://www.sparkfun.com/products/10253).

The voice readout is triggered by the automatic bluetooth connection from the device when it comes into range of your droid running F3K Master.

This connection event can also stop the F3K Master flight timer for you (see option under menu > wireless > land on connect).

This functionality is included in both the Play store versions of F3K Master.

After getting the device working (it beeps once - see below!),
From F3K Master, press menu > wireless, and enable bluetooth.
From F3K Master, press menu > more > Connect Bluetooth

This firmware version will also work on an altimeter that does not have a bluetooth module installed (want to try it with an Alula?)

Additional Firmware Features
- Added bluetooth functionality using RN-42 bluetooth module.
- Added Alula Mode which uses settings on the launch detector that work for an Alula!
- Added Bluetooth TX power option (higher to connect further away and lower to connect as you catch the plane).




Warning: There is a chance that the bluetooth device will reduce the effective range of your radio link. Use the lowest bluetooth power that works for you and range test your radio. You should also position the bluetooth module as far away from the receiver's antenna as you can.
You use the device and these instructions entirely at your own risk!!

Building it:

Connecting the RN-42 involves some fine soldering:

RN-42 pin 5 (RESET) --> OA reset (Serial connector pin 6 directly - no capacitor) 
RN-42 pin 11 (VDD) --> OA 3.3V (output pin of SMD regulator)
RN-42 pin 12 (GND) --> OA GND (Serial connector pin 1)
RN-42 pin 13 (RX) --> OA TX (Serial connector pin 5)
RN-42 pin 14 (TX) --> OA RX (Serial connector pin 4)

(the left picture above is missing the reset wire - it is needed!)

Initializing the RN-42
On first startup, the RN-42 will be discoverable and should be visible to other bluetooth devices.
Connect to the device from a pc over bluetooth using a terminal app of your choice. 115200 baud, 8 data bits, no parity, 1 stop bit.

1) Once connected, in the terminal app type

$$$

If you get "CMD" as the response, you are in - proceed to the next step.
If not, try connecting to the device with bluetooth again. You must enter the '$$$' within 60 seconds of powering on the device. Power off and on to retry!

2) Type

SU,57

and hit enter (response will be "AOK") to set the correct baud rate

3) Type

SD,020C

and hit enter (response will be "AOK") to set the device class to allow this device to auto connect to the droid.

4) Type

R,1

and hit enter (response will be "Rebooting!")

You're done! In the future, you will be able to do this with the Android app.

On startup, the usual startup tone is played followed by:
"0" double beep: The device is discoverable and ready for you to connect to it. From F3K Master, press menu > more > connect bluetooth.
4 beeps: The device was unable to setup the bluetooth module. Disconnect it from the USB adaptor (it will likely not work with the FTDI adaptor attached) or check the connections and try again?

The code for pairing is 1234

NOTE: The RN 42 relies on the DTR (used as a reset) to stay low while the downloader app or firmware update are communicating with the altimeter. Some Windows serial ports do not do this (Mac does). The symptom (only with the bluetooth module module installed) will be partial or no communication with the device over the serial cable and firmware update will fail. There are some workarounds if anyone is interested!


Enjoy!

I have attached the source files for the downloader and firmware.

I just managed to get everything done in the size limit of the firmware! I'm sure it can be optimized.

Also, no time to do the exe installer yet!

Firmware V2 attached - modified Alula settings and split LAUNCH_DETECTOR_REARM_HEIGHT parameter for DLG and Alula.

I've said it elsewhere, but it should be said again ... this is cool!


Jony

I updated the apk file. Please download the new version! (It was crashing if the altimeter data transfer had some strange numbers. Moved the Connect Bluetooth menu item to the top)

do you have any pics of all the solder points? you state there is a wire that is soldered that is not shown in the pic. I am confident I can do the soldering, having a reference picture would be helpful.

Also will this work with a regulator installed on the OA? It can easily be removed, just curious.

Hello Alan

I have added an image for the solder points. The device would work just fine with the glider power regulator in place.

Adrian

Updated all the downloads. Please let me know if there are any problems!

Thanks for the new pic, that does not look to hard. I think I am going to pull the regulator so that the OA can be pulled out if needed and not affect the rest of the electronics. and then I can move it from plane to plane.

Hi,

question, what's the range of the bluetooth Module? Can i only get the height if i land my plane?

Patrick

The RN-42 is a class 2 device with a range of around 30 meters (100 feet) so it is not likely you can still be connected at the top of the launch.

It may be possible with a class 1 device (RN-41 with a potential range of 100 meters or 300 feet) but there is also a chance it will interfere with your radio link.

Got two RN-42 the other day, man these are tiny! going to solder one up this week. Looking forward to testing it out.

Originally Posted by extremewing

The RN-42 is a class 2 device with a range of around 30 meters (100 feet) so it is not likely you can still be connected at the top of the launch.

It may be possible with a class 1 device (RN-41 with a potential range of 100 meters or 300 feet) but there is also a chance it will interfere with your radio link.

do you check a class 1 device with a Futaba 2,4Ghz Rx?

I have not used a class 1 device with my Futaba, no.

Also, the Class 2 device needs to be on a lower power setting than full to connect at the right time as you land the plane if you want it to stop the timer.

The device needs to be as far from the receiver's antenna as possible to avoid interference too.

Please make sure you range check your radio!

Hi Adrian,

thanks a lot for your fantasic work again! I got my BT module this weekend and managed to get it running easily.

The only problem is that what you wrote here:

Originally Posted by extremewing

NOTE: The RN 42 relies on the DTR (used as a reset) to stay low while the downloader app or firmware update are communicating with the altimeter. Some Windows serial ports do not do this (Mac does). The symptom (only with the bluetooth module module installed) will be partial or no communication with the device over the serial cable and firmware update will fail. There are some workarounds if anyone is interested!

How can i fix this?

Regards
Markus

Enjoy!

Hello Markus

I was wondering when someone would ask

Note: This only applies to Windows

Problem:
You connect the USB adaptor to a BTOA.
You hear the OA startup tones.
You cannot connect to the OA from the downloader or flash it.

Resolution:
Open device manager (Right click My Computer, select Manage, select Device Manager)
Expand Ports
Find the one named "USB Serial Port" (with the "comX" that you should be using in the downloader app)
Double click it and choose the "Port Settings" tab.
You can leave the settings as they are, but press on "Advanced"
Make sure your com port is correctly selected and check "Set RTS on close"
Press OK twice.

Now your downloader app should work, but not the flash utility.

To flash the device, either:
Remove one connector to the RN42 (RX on OA side)
OR
Short out the outer two pins of the connector on the OA just as you press the flash button.
Remove the jumper when the flash process is complete so the OA restarts.
Power off the device and on again to use.

You may need to play with the timing a bit to get it to reset at the right time as you press the flash button in the downloader - roughly a second or two after pressing the button - and let it be still while flashing since disturbing the connection will reset the flash process (I have not damaged a device by reseting while flashing yet either).