Home Brew Telemetry

[jsmcms]

Thanks for the template. How did you know I was planning to redo the lid?
By the way, what analog ports did you use for the switch? I think you used 0-4 (up, down, left, right, center), right? I'm not familiar with the const int xxBut = xx command to figure it out.

[RobDrech]

The "const int" just means that the code holds the integer constant and does not expect it to change, like pin definitions (it uses less mem than a normal int).
The "up/dn/rt/lt/cnBut" are simply the up, down, right, left and center buttons variables.
The "= 14;" is another way of saying the analog pin A0... so A0 = pin14, A1 = pin15, etc.

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Still chugging along with v1.0...

New parts added to v1.0:

Female to Female rainbow wires (really, any wire can be used but these are by far the easiest)
Right angle headers
Transistor PN2222
1N4001 Diode
270 Resistor
Small thru-hole circuit board
A power switch

There will be a need to cut/modify and solder the wiring for some connections, as well as building an additional circuit so get that soldering iron hot.

We have to make a small little circuit that will switch power to the vibrator motor. The issue is that the motor may draw more than an arduino pin can safely and will burn out the pin.

Here is the safe way to control a high draw component from an arduino pin. This will add a few dollars to the build but it's better than wrecking a arduino board/Atmega processor. Here is a link to Adafruit for the full walk thru on the motor driver.



Use the right angle headers to convert the arduinos female headers to males as shown. The right angle headers will give a little clearance in the enclosure between the arduino and the boards mounted above. I squash the pin toward the plastic retainer to get more pin inside of the female headers... haven't had a issue yet doing it this way!





The final pinout from the arduino to the other components are as follows:

Arduino --------> Component

RX ---------------> Xbee Shield TX
TX ---------------> Xbee Shield RX
3 -----------------> Nokia Screen\
4 -----------------> Nokia Screen|
5 -----------------> Nokia Screen|All of these will connect thru the level shifter. Here is the link to the instructions.
6 -----------------> Nokia Screen|
7 -----------------> Nokia Screen/
8 -----------------> Buzzer +
9 -----------------> Vib Motor signal
A0 ---------------> Down Button
A1 ---------------> Up Button
A2 ---------------> Right Button
A3 ---------------> Left Button
A4 ---------------> Center/Select Button
3.3v -------------> Nokia Screen VCC
5.0v -------------> Xbee Shield VCC
GND ------------> Will need to be split into two, Nokia Screen GND and Buzzer GND
GND ------------> Will need to be split into two, Button GND and Battery GND
GND ------------> Will need to be split into two, Xbee Shield GND and Vib motor GND
Vin --------------> Battery + (not more that 12v per Arduino's documentation for the Uno. Varies by model so DOUBLE CHECK!







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[jsmcms]

Hi Rob,

Good catch on the motor driver. I hadn't connected one because there was something about it that was bugging me. It was the counter EMF diode. I didn't think about the Arduino limitation. Thanks for the alert.

I've joined Fritzing.org. I'm fairly impressed on it's utility. I tend to use the schematic mode but I can see how the breadboarding mode has merit. Where did you get the part for the Nokia 5110? Did you build it yourself or download it? I didn't see a source from Adafruit but maybe I missed it. I'm building the schematic for the Home Brew Telemetry using the Fio and I'm missing the Nokia.

I hope you don't mind me asking you questions. Your work is really good and I've obviously taken great interest. I think you're pretty darn close to making something that will really help the average flyer. And the cool part is you can build it yourself!

Anyway, I've got to work for a living this week but hopefully I can get this finished over the weekend.

Cheers, Scott

[RobDrech]

I don't quite remember where I found it... I think someone actually made it and posted it on the Fritzing site. Anyway, here is the file.

As for questions and what not, I think that they are part of a collaborative effort and only make the project better, so keep em coming. I hope that a few people join in and show what they have come up with too... This way we can keep the ideas coming in and maybe end up with a stellar DIY project.

[jsmcms]

Hi Rob,

Thanks for the file. I'll finish the schematic a bit later.

I've run into a problem. I get "normal" data as long as I do not connect the 5-way switch. When I connect the switch, I get this:



I've tried a few decoupling techniques, a different power source and simply re-routing the wiring but no joy. Have you seen anything like this? I'm beginning to think that the display or the Fio is not working right. Maybe it's the chip speed or I'm running the xBee too fast (111111 baud). Every now and then it works just fine but it's hit or miss.

Thoughts?

[RobDrech]

Scott,
Which code are you using? The rx unit is too slow to catch the every start of the streaming data, so it's missing the first few pieces of the tx data and catching the rest. It happened to me too. It's actually working right, you are just seeing some other motor data and what not. Try this code. It controls the data a little better.

let me know.

[RobDrech]

Huh... I think I see what you mean. I am able to boot it up and let it run for a few minutes with the SF switches but every now and again the data gets corrupt. I'm not sure if I'm getting interference or what. I have a lot of 2.4ghz crap in the house and wonder if today is more polluted than normal.

*edit* Mine is interferrance... It's been on for 20 minutes now and has been fine. I just changed rooms.

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Closing out v1... Let me know if anyone has any questions.






http://www.youtube.com/watch?v=2WYkf0hNun8

[jsmcms]

Hi Rob,

Mine is still having trouble. I don't think it's interference. It acts like each time it cycles through the program the registers for heading altitude and battery are getting summed with the next reading. I put in a long delay before the first 'x' transmission. It holds fine but then each time the program cycles and stops at the delay, the readings get worse and worse. I don't appear to loose xbee connection (RSSI) never turns off. I'm wondering if there is something in the Fio that is or is not processing as expected. It seems like it should be something simple to sort out but I've just really started looking at the code.

More later, Scott

[RobDrech]

And your using the code that I posted above?

[jsmcms]

I am. I think I'll comment out everything but the serial and data grab portion to play with some delays and see if I can get a steady display. Then add in the edit and alarm sections to see what happens. I tried slowing down the baud rate and moving the quad and receiver to different rooms but no joy.


You mentioned before that the data stream doesn't have a header. Is there is another way to qualify the received data before it gets processed? Perhaps counting the number of received digits and determining the spacing between commas might work. It does seems like something on the serial side because the edit and alarm functions seem ok.


That's where I am. I did finish up the power connection to the transmitter yesterday. I'll take some picture and post later. I'll probably finish the hardware over the next day or so but first I want to work on the data problem a bit.