Building a satellite

[Julian5]

Short update since I have not posted in a while!

I received the magnetometer, accelerometer, barometric and temperature sensor. I also received a sponsor from pcbway for the pcb's themselves which is nice. I also found a solar panel provider and have received some samples even though they are supposed to send more after CES. Im currently busy programming the code with an arduino nano, integrating the sensors into the pcb and will soon order a rework station since the pcb is fully composed SMD and BGA chips. 

[ShredBird]

Congrats on the sponsors and glad to hear you're getting a rework station!  SMD isn't too bad if you have the right solder tip, but BGA is definitely much harder.

[Julian5]

On 17/1/2018 at 5:25 AM, ShredBird said:

Congrats on the sponsors and glad to hear you're getting a rework station!  SMD isn't too bad if you have the right solder tip, but BGA is definitely much harder.

Thanks, SMD parts are ordered and I'm just finishing up the PCB before I send it for manufacturing. Unfortunately, 2 of the chips I'm using are bga but i'll have over 10 boards to practice so I think I'll be fine. I have also tested an Arduino mini pro with some breakout boards for the components I'm using and I have managed to get Text to speech working to transmit data, currently working on setting up RTTY transmissions. I tested the small 433mhz tx and it seems to work as far as I have been able to test it line of sight. However, as soon as I test the pcb I will change the transmitter to something more efficient and powerful like an RFM22. Just having trouble again with the solar panels......

[Canada EH]

On 11/4/2017 at 9:02 AM, Ryan_Vickers said:

he stuff they carry tends to come straight back down

yup usually with 10-15km depend on wind I guess.

maybe try the balloon then a rocket. I know theres different types of space balloons you can buy, but they are not cheap.

I wonder though it thats legal, doing a rocket on the balloon to get more height.

Where do the laws of the country end in terms of height into the atmosphere/space.

 

 

 

 

 

The interface between the Earth's surface and outer space. The Kármán line at a height of 100 km (62 mi) is shown. The layers of the atmosphere are drawn to scale, whereas objects within them, such as the International Space Station, are not.

 

 

 

 

 

 

 

 

 

[Julian5]

24 minutes ago, Canada EH said:

yup usually with 10-15km depend on wind I guess.

maybe try the balloon then a rocket. I know theres different types of space balloons you can buy, but they are not cheap.

I wonder though it thats legal, doing a rocket on the balloon to get more height.

Where do the laws of the country end in terms of height into the atmosphere/space.

 

 

 

 

 

The interface between the Earth's surface and outer space. The Kármán line at a height of 100 km (62 mi) is shown. The layers of the atmosphere are drawn to scale, whereas objects within them, such as the International Space Station, are not.

 

 

 

 

 

 

 

 

 

I have been checking the laws for this in Spain and its fairly easy, if done legally you just need to fill in some forms and request an airspace reservation. However, with this thing weighing well under 50g I doubt it will even need to be done.

[Canada EH]

2 minutes ago, Julian5 said:

However, with this thing weighing well under 50g

Is that including all the flight mechanisms? Weight of balloon etc

[Julian5]

6 minutes ago, Canada EH said:

Is that including all the flight mechanisms? Weight of balloon etc

The total weight will be around 80g with the balloon

[Julian5]

Update!

Sorry for the slow updates I have been very very busy with exams lately. However, I have just received the free sponsored PCB from PCBWAY and they are working fine, Transmitting heading, g-force, temperature and height on 433mhz. I have also received the SMD rework station and will order the smd PCB soon once the final design is done.

[Julian5]

3 minutes ago, Pangea2017 said:

@Julian5 why the bme180 and not a bmp28 or the new bme680?

mainly due to cost, works fine for what I need though

[ShredBird]

Awesome progress!

[Julian5]

Just now, ShredBird said:

Awesome progress!

Thanks, to be honest the current pcb is kind of useless and is just a proof of concept, ill call this half done once I actually get the smd version working!

 

[Julian5]

The worlds worst designed PCB ever! V1 will be ugly but hopefully, it will work lol, it measures 35mm x 48mm and its still missing the magnetic sensor in the bottom right of the pic (thus the empty space). This is gonna be a bitch to solder.

Please let me know if there's anything I'm doing wrong since I'm just making this PCB without much previous experience. 

Thanks.

[ShredBird]

41 minutes ago, Julian5 said:

The worlds worst designed PCB ever! V1 will be ugly but hopefully, it will work lol, it measures 35mm x 48mm and its still missing the magnetic sensor in the bottom right of the pic (thus the empty space). This is gonna be a bitch to solder.

Please let me know if there's anything I'm doing wrong since I'm just making this PCB without much previous experience. 

Thanks.

Just some general tips.  For power lines and grounds use the biggest trace you can get away with.  Generally you want one whole plane of the PCB to be VCC while the other plane is ground.  Also, it's good practice to place filtering capacitors near your digital chips VCC if possible, 100 pF or so.  This will smooth out any noise picked up by your traces and wires coming from the battery / power source.

Really not bad for your first go, however, good job!

[wirs]

Also try not to do 90° bends with the traces, always go for 45°.

[ShredBird]

6 hours ago, wirs said:

Also try not to do 90° bends with the traces, always go for 45°.

That's not actually too big of a concern unless the manufacturer can't physically build it due to outdated tooling.  Where it becomes important is if you are building a microstrip with an exact impedance for high frequency.

[Julian5]

9 hours ago, wirs said:

Also try not to do 90° bends with the traces, always go for 45°.

 

3 hours ago, ShredBird said:

That's not actually too big of a concern unless the manufacturer can't physically build it due to outdated tooling.  Where it becomes important is if you are building a microstrip with an exact impedance for high frequency.

 To be honest this first design is just to make all the connections and at least one if not many will be wrong. I already found 2 errors in the red protoboard I designed upon assembling it. Luckily you can fix them with jumper wires but thats why V2's exist haha.

Some of the lines in the design are not even straight but ill go over it again tomorrow to make it look a bit neater and have more equal spacing and fix the 90º traces. Thanks! 

[Guest]

1000% go to America like Midwest or whatever and launch it. There are many places you can launch anything you want without regulations. 

[Julian5]

8 hours ago, fpo said:

1000% go to America like Midwest or whatever and launch it. There are many places you can launch anything you want without regulations. 

Hahaha, I'll start a gofundme to go to America for the launch! It would probably be cheaper to launch the actual thing to LEO. I don't mind dealing with paperwork for a 20g payload even though its a bit excessive, I'll definitely have to travel through since I live 5km from the closest airport and 20km from the largest in Spain right now. I'd also rather launch it here than in Switzerland since regulations are even worse there.

[straight_stewie]

15 hours ago, fpo said:

1000% go to America like Midwest or whatever and launch it. There are many places you can launch anything you want without regulations. 

No, there aren't. However, there are certain places where the FAA makes "special dispensations" in that you ask them nicely for permission and they almost always give it if you have all necessary information. They still have to put out NOTAMS.

[iHDCool]

I don't actually understand these stuff so pardon, but I gotta say you must be really fucking smart lol.... 2 questions, first, what school did you finish or what are you studying rn, and second, in theory, what would happen if you just launched the thing without any premission or anything. Just yolo it, or there's no restriction to launching something like this? Keep up the good work  

[straight_stewie]

I Found some information that may influence your design:
https://www.faa.gov/aircraft/air_cert/design_approvals/balloons/balloons_regs/

[Julian5]

On 6/3/2018 at 11:19 PM, iHDCool said:

I don't actually understand these stuff so pardon, but I gotta say you must be really fucking smart lol.... 2 questions, first, what school did you finish or what are you studying rn, and second, in theory, what would happen if you just launched the thing without any premission or anything. Just yolo it, or there's no restriction to launching something like this? Keep up the good work  

 

2

@straight_stewie @iHDCool

 

Well, Im just studying high school right now but to be honest I look at too much stuff online haha. I doubt anything would happen if I sent this up without permission but I don't want to risk a 10k € fine so I'm trying to go legal first.

 

On 7/3/2018 at 6:51 AM, straight_stewie said:

I Found some information that may influence your design:
https://www.faa.gov/aircraft/air_cert/design_approvals/balloons/balloons_regs/

 

Thanks! The rules are slightly different in Spain though.

4e22f886-257f-46e1-ab44-b50a4a05c5bd.mp4

 

Here is a test video with some simple accelerometer correct heading, temperature and altitude, pretty happy with it so far even though it's missing a lot of things. I actually tested it out with 1 solar panel and it worked fine too. Next step is including RTTY for more data but let me know what you think. I also invite any of you to make up some code for this if you wish and i'll test it out for you. Now I just have to check and order the smd version and order it with the donation PCBWAY made.

[Julian5]

Update!

SMD Pcb arrived yesterday and I finished soldering it, Took some time but was easier than I thought and I'm pretty happy with the result. Now I just need to do some more testing on it and continue programming. Anyways here are some pics comparing with the older version and with a 1 franc coin for size.

 

Spoiler

 

 

[ShredBird]

Awesome to see this coming along!

[bob345]

On 3/23/2018 at 5:00 AM, Julian5 said:

Update!

SMD Pcb arrived yesterday and I finished soldering it, Took some time but was easier than I thought and I'm pretty happy with the result. Now I just need to do some more testing on it and continue programming. Anyways here are some pics comparing with the older version and with a 1 franc coin for size.

 

 

Looks good, definitely room for some more improvement id say though. My main concern with this setup is the RF side. Range will be severely limited with an antenna that small on such a low power radio. I would say you would be lucky to see a few hundred feet at best line of sight. You really would need a larger antenna and a more powerful transmitter ( ≥ 100mw) you you want to realistically gather data at altitude with it. I would try and pick up something like a cheap rtl-sdr usb dongle to use as a low cost spectrum analyzer to see what you are doing.  RF can be a tricky thing to get right, the more testing you can do in that regard the better. When dealing with low power and long range, every little thing can effect your signal down to the traces on the pcb and the brand and placement of components.