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LaunchPad AlTImeter Technical Support Forum

Discussion about deployment systems including altimeters, timers, air speed flaps, servo systems, and chemical reactions.
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U.S. Water Rockets
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Re: LaunchPad AlTImeter Technical Support Forum

Post by U.S. Water Rockets » Tue Feb 24, 2015 9:17 pm

tonyvs wrote:Hello there!
Here are a few pictures of my launch pad and a video where you can hear the sound and see that all the lights are lit. The mode button has no effect, the reset button does stop the sound and switch off led1 and led 2 whilst I keep it pressed.
One thing that jumps out right away is that the board with the pressure sensor appears to be a clone of the Sparkfun board. It looks like it may not be an exact clone, so we'd have to look at the board in more detail to tell if it is compatible. The images are not large enough to read the text, so if you could copy the text written on the green board and also the letters/numbers on the pressure sensor on the green board (the large silver metal component with the hole in the top).

Another thing to try is to see if the board responds to the configuration setup mode. You should attempt to follow the directions for setting the servo deploy polarity in the manual and see if the board acts differently. It *should* let you toggle the servo left and right and set the deploy position to your preference. Try and see if it does that to verify that the code is running properly and the servo is working well.

See what happens and report back as soon as you can.



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Re: LaunchPad AlTImeter Technical Support Forum

Post by tonyvs » Wed Feb 25, 2015 8:13 am

Hi

The preasure sensor is hobbytronics.co.uk. The model number is MPL3115A2 Altitutude Sensor. The pins are labeled I2, I1, SDA, SCL, 3V3 & 0V from pins P1.2 to 2.1.

I think the board responds to the configuration setup mode. This is what I have done:

1. I switch on the board, whilst holding down the Mode button I press and then release the Reset Button.

The Red and Green LEDs come on and stay on.

2. I release the mode button.

The Red LED alternates between ON and OFF approx once every second.

The servo rotates backwards and forwards until I press the Mode button again.

I attach a video so you can see it.

Hope this gives you some clues as to what is wrong.

Thanks.
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Re: LaunchPad AlTImeter Technical Support Forum

Post by U.S. Water Rockets » Wed Feb 25, 2015 7:00 pm

tonyvs wrote:Hi

The preasure sensor is hobbytronics.co.uk. The model number is MPL3115A2 Altitutude Sensor. The pins are labeled I2, I1, SDA, SCL, 3V3 & 0V from pins P1.2 to 2.1.

I think the board responds to the configuration setup mode. This is what I have done:

1. I switch on the board, whilst holding down the Mode button I press and then release the Reset Button.

The Red and Green LEDs come on and stay on.

2. I release the mode button.

The Red LED alternates between ON and OFF approx once every second.

The servo rotates backwards and forwards until I press the Mode button again.

I attach a video so you can see it.

Hope this gives you some clues as to what is wrong.

Thanks.
That troubleshooting actually nails down the issue. The MSP430 cannot communicate to the sensor for some reason. It appears the green board is positioned correctly so that leaves a few possible causes:

1) The MSP430 Chip is damaged or defective. Did a spare MSP430 come in the package with your LaunchPad? You can try swapping it out and programming the new chip. Just pry the MSP430 up with a small screwdriver and it will pop out of the socket.
2) The MSP430 Chip is not plugged in correctly (check the leads are not bent under the chip).
3) The sensor green board is not soldered well to the Launchpad. It's hard to tell from your images, because you used a lot of solder and the images are not the highest resolution, but if the sensor is not making contact with the pins, the sensor can malfunction. You could try touching up the solder joints of the sensor board.
4) There is a short circuit on the sensor solder connections. Look for any excess solder that might be connecting adjacent pins on the sensor board or Launchpad. Sometimes these are too small to see with the naked eye, so look with a magnifier.
5) Something is incompatible between the sensor you use and the one called out from Sparkfun. We will check into this.
6) The sensor was shock damaged somehow. If you ever had the sensor on a rocket and crashed it hard, it can kill the sensor. Similarly, stepping on it or whacking it can break the sensor as well.
7) The sensor was static damaged by a zap of static electricity. It's possible it was hit with a static discharge, like any electronics it can be damaged by this.
8) The sensor board is simply defective. It's always possible the manufacturer did something harmful to the sensors while manufacturing the boards or assembled it incorrectly.

That's a pretty comprehensive list of every possible malfunction of the sensor. Hopefully something pans out.



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Re: LaunchPad AlTImeter Technical Support Forum

Post by tonyvs » Thu Feb 26, 2015 2:34 pm

Thank you very much for your comprehensive diagnostics:
1) With regards to the MSP430 Chip, the one in the pictures and videos is the spare one. I changed it and reloaded the firmware again before asking for help. The results were the same.
2) I have looked and the MSP430 Chip, it is plugged in correctly, none of the leads are bent under the chip.
3) Under the magnifying glass I can see that the solder does not reach all the way down onto the green sensor board at points I1 & SDA so it may not be soldered well onto the Launchpad. I will try touching up the solder joints of the sensor board. (hopefully it will be this!!)
4) Although there is excess solder (due to my lack of soldering experience!!) on the connecting adjacent pins on the sensor board they are not shorting. I have carefully looked with my magnify glass
5) We do not know for now if my sensor is incompatible.
6) The electronics have not flown yet (except via airmail to Spain!!)
7) I don’t think the sensor was static damaged by a zap of static electricity although I cannot be sure of this.

I will let you know how I get on. Thanks again for your time.



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Re: LaunchPad AlTImeter Technical Support Forum

Post by U.S. Water Rockets » Thu Feb 26, 2015 8:02 pm

tonyvs wrote:Thank you very much for your comprehensive diagnostics:
1) With regards to the MSP430 Chip, the one in the pictures and videos is the spare one. I changed it and reloaded the firmware again before asking for help. The results were the same.
2) I have looked and the MSP430 Chip, it is plugged in correctly, none of the leads are bent under the chip.
3) Under the magnifying glass I can see that the solder does not reach all the way down onto the green sensor board at points I1 & SDA so it may not be soldered well onto the Launchpad. I will try touching up the solder joints of the sensor board. (hopefully it will be this!!)
4) Although there is excess solder (due to my lack of soldering experience!!) on the connecting adjacent pins on the sensor board they are not shorting. I have carefully looked with my magnify glass
5) We do not know for now if my sensor is incompatible.
6) The electronics have not flown yet (except via airmail to Spain!!)
7) I don’t think the sensor was static damaged by a zap of static electricity although I cannot be sure of this.

I will let you know how I get on. Thanks again for your time.
The lack of solder on the SDA pin could be the real issue here. The I1 pin is not critical to the function of this project.

According to the website and datasheet, the green board is a clone of the sparkfun board, so it should be compatible. If you get it working it might be nice to recommend as an alternative.

Good Luck!



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Re: LaunchPad AlTImeter Technical Support Forum

Post by tonyvs » Sat Feb 28, 2015 12:13 pm

I can’t thank you enough!!

Yes, it was the lack of solder on pin SDA of the pressure sensor. As soon as I retouched the solder, I plugged in the battery and it worked just like on your videos.

My next step was to simulate a launch. As I mentioned in my first post, I have been watching all your videos and reading stuff on your site for months, and I knew that once I had the electronics ready I would want to test it before putting it inside a rocket.

I saw the “Water Rocket Altimeter Bench Tests” video but realized I had no way of getting a vacuum pump like yours, so I started to investigate. I found a video on YouTube which describes how to convert a garden spray pump into a vacuum pump. http://youtu.be/0pfPOuzLPuw. (It’s in Portuguese but very well visually displayed).

I wasn’t sure if this was going to produce a big enough vacuum but the total cost of it was around 6€ so I didn’t have much to lose.

As soon as I got the electronics working I hooked up my manual vacuum pump to a glass jar, armed the launcher by pressing the mode button for 5 seconds, the red and green lights began to alternate, beeping for the first few seconds then silent, after 30 seconds just the green light flashed with an intermittent beep.
I pumped up the spray pump, released the switch on the spray to create the vacuum, the red and green lights flashed together which detected takeoff, then the red light stayed on whilst the green was intermittent, detecting flight, and finally they both lit together when the servo motor was activated.

It then beeped the maximum height, this varied from 150 to over 1000 feet, depending on the vacuum applied on different test.

I attach a picture of the setup.

We are really excited, we hope to launch our first rocket with parachute in the next few weeks. I still have to make the parachute and the nose cone for the electronics; will let you know how we got on. I don't think we will get anywhere near your record, but will have lot of fun trying!!

Again, thank you very very much for your help!!
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Re: LaunchPad AlTImeter Technical Support Forum

Post by bugwubber » Mon Mar 16, 2015 4:11 pm

Something came in the mail today...

Debating on waiting until the hakko arrives to build though.
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Re: LaunchPad AlTImeter Technical Support Forum

Post by bugwubber » Tue Mar 17, 2015 7:09 pm

Yep couldnt wait. Soldered up with my cheapy, abused soldering iron. Appears to be working now.

Impressive how angry this thing gets if you accidently install the pressure sensor on the 5-10 pins instead of 4-9.

Tiny phone screen made that detail a little hard to see.

Now to install..
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Re: LaunchPad AlTImeter Technical Support Forum

Post by anoymous » Wed Mar 25, 2015 4:25 pm

Hi
Can someone plz answer on my post in the link? (I posted it on the wrong place and don't know how to move it)http://wra2.org/forum/viewtopic.php?p=17883#p17883


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Re: LaunchPad AlTImeter Technical Support Forum

Post by U.S. Water Rockets » Wed Mar 25, 2015 11:10 pm

bugwubber wrote:Yep couldnt wait. Soldered up with my cheapy, abused soldering iron. Appears to be working now.

Impressive how angry this thing gets if you accidently install the pressure sensor on the 5-10 pins instead of 4-9.

Tiny phone screen made that detail a little hard to see.

Now to install..
Awesome! Hopefully another happy customer! It's so cool to see other people building and using our design. One thing is it looks like the connection on the VCC pin of the pressure sensor board is a little wonky. You might want to touch it up a bit when you get a better iron.

Let us know how it works.



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Re: LaunchPad AlTImeter Technical Support Forum

Post by U.S. Water Rockets » Mon Apr 06, 2015 7:56 pm

I think I will just leave this right here.
graph.jpg
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Re: LaunchPad AlTImeter Technical Support Forum

Post by Blenderite » Mon Apr 06, 2015 8:29 pm

How did you make that?


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Re: LaunchPad AlTImeter Technical Support Forum

Post by bugwubber » Mon Apr 06, 2015 9:27 pm

Data logging for AlTImeter?


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Re: LaunchPad AlTImeter Technical Support Forum

Post by Blenderite » Tue Apr 07, 2015 8:43 am

bugwubber wrote:Data logging for AlTImeter?
I hope so!!!


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No sound

Post by motorcyclepilot » Sun Jul 19, 2015 5:46 pm

Just finished building, per the very clear instructions. A fun project! Bench test went great! Lights blinked, button pushes did as expected, and the servo motor servo'ed. The only exception is no sound form the speaker. All parts were "OEM" except the battery, a Turnigy 1s 360. Re-checked all solder joints and they look good to me. Put a meter to the speaker and tested from the meter to the pins on the mc socket and continuity was good. Re-flowed those joints, just in case. Not sure if I can apply a test voltage across the speaker pins safely.

Guidance please?



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