Raspberry Pi Forums

Greeting, everyone!

I am writing from Florida, USA and I am attempting to put together a Astro Pi.

I'm a bit of a space/NASA geek and I've always wanted to learn how to programming, 3D-printing, and working with electronic parts. It was exciting to for me to read articles on Astro Pi and I see Astro Pi as a great opportunity to learn my aforementioned desires. I am a photographer by trade, so this is a new direction and experience for me.

I've got a Raspberry Pi 3 B, the Sense HAT, the camera v2.1 board, and I had the Flight Case printed out by a local 3D printer. The remaining tasks left for me are getting the electronic parts and putting it all together. Getting the electronic parts has proven to be a tricky endeavor for two reasons; I am a total newbie to electronic parts and the only place I can see where I could get all the parts in a kit is at this link: http://cpc.farnell.com/ucreate/uc-apk-c ... dp/SC14158 . I've been in contact with this company and for various reasons, it is not practical for me to buy the kit from CPC.

So now I am attempting to source the parts individually and locally. I am basing my list off the part list shown in this link (scroll down to almost the bottom of the web page): https://www.raspberrypi.org/learning/as ... worksheet/ . But this list is too generic for me to adequately source the parts with. It assumed I know what I'm doing, lol.

The bolts, nuts, washers, screws, and standoffs, I probably can find those in a local hardware store.

The tactile buttons, I've found a set at www.amazon.com. They looked similar enough to the Astro Pi worksheet's images.
https://www.amazon.com/Yosoo-button-Loc ... ton+switch

It's the wires, the header, insulation boots, and friction fit crimp I wish to seek further clarification on in order for me to find them locally.

"Jumper wires"; will any do? What gauge am I looking for? 16?

"Length of black wire"; I saw 50cm in the CPC link so I have the required length. Same gauge as jumper wires?

"insulation boot" and "friction fit crimp"; I think I can find these at a local marine store, but could someone clarify on exactly what insulation boot and friction fit crimp I am looking for?

"Extended 23-way pin header": finding the right header is giving me the most difficulty because I don't know anything about headers. This is a first for me. I've manually looked through results at www.amazon, www.adafruit.com, www.mouser.com and www.digikey.com and I could not find a suitable header (results either doesn't have the correct header or are too numerous for me to adequately go through). I did found a 20-pin header and a 40-pin header at www.adafruit.com; is one of those a suitable replacement? Also, what is the height requirement for a header that will work with Astro Pi?

As you can tell, I'm pretty green to this, lol, and it's a little embarrassing for me to ask such basic questions. But I wish to learn. Especially on the header, I will appreciate any information you can spare.

olav

• female-to-female jumper wires
• Extended 23-way 26-way pin header
• Friction fit crimp
• M2 cross-head screw
• M2.5 cross-head screw
• M2.5 washer
• M2.5 nut
• M4 hex nut
• M4 bolt
• M2.5 male-to-female stand off
• M2.5 male-to-female stand off
• Tactile push-buttons
• Length of black wire

All of my search results focus on UK suppliers so I'm using amazon.com where possible.

Female to female jumper wires:
Aka dupont wires.

23- way pin header is a misprint, it should read 26 way pin header, like this one.

It would probably be easiest tho solder the wires to the buttons, if you don't fancy this you need to find the crimp lug that best fits your button end connector.

The insulation boots should be sized for the crimp lug (or you could buy pre-insulated crimp lugs and skip the insulation boot) or use heat shrink insulation to cover the lug.

The actual wire size won't matter much, whatever you can find as they won't be carrying any real current. AWG 16 - 20 will all be fine.

Helpful replies, Doug!

That cleared up a few misunderstandings I had (jumper cables also called dupont wires; misprint 23; search for 2x13, not 2x26, lol). That yielded the search results I was expecting. As for the wires and boots, it sounded like I may be overthinking that one. As long they are correctly connected and insulated, I should be good for it. Gotcha.

Thank you!

olav

olav216 wrote:Helpful replies, Doug!

That cleared up a few misunderstandings I had (jumper cables also called dupont wires; misprint 23; search for 2x13, not 2x26, lol). That yielded the search results I was expecting. As for the wires and boots, it sounded like I may be overthinking that one. As long they are correctly connected and insulated, I should be good for it. Gotcha.

Thank you!

olav

You are welcome, yes, the cables will only be carrying milliamps and only when the GPIO input is connected to gnd (button pushed). so no real worries about cable size.

In the US like me might want to check out www.adafruit.com and/or www.sparkfun.com.

Both good prices and lots of choices good delivery!

Ken

THE CPC link actually gives you a list of what everything looks like
http://www.farnell.com/datasheets/2236328.pdf
and worksheet two should show you how it goes together so you can work out what would work for you with what you can get hold of.
Also look at aliexpress and other sites for parts.
https://www.raspberrypi.org/learning/as ... orksheet2/

KMyers wrote:In the US like me might want to check out http://www.adafruit.com and/or http://www.sparkfun.com.

Both good prices and lots of choices good delivery!

Ken

Thanks, Ken! I've visited adafruit.com (great site!) but sparkfun.com is new to me. It looks like a good one!

bensimmo wrote:THE CPC link actually gives you a list of what everything looks like
http://www.farnell.com/datasheets/2236328.pdf
and worksheet two should show you how it goes together so you can work out what would work for you with what you can get hold of.
Also look at aliexpress and other sites for parts.
https://www.raspberrypi.org/learning/as ... orksheet2/

I went back to the CPC link to look for that pdf. That was obscure, lol. The pdf will be handy to have. Previously, I have been using this video to get a closer look at the part items. Great instructional video on how to put together the Astro Pi, by the way.

Youtube: How to build 3D printed Astro Pi Flight Case
http://www.youtube.com/watch?v=kY1db5cec64

CPC's pdf still doesn't have the part numbers so I'll print it out to bring with me when I go visit the local hardware/marine stores for the metal parts (bolt, nuts, etc) and the insulation parts. Thanks, bensimmo!

Between all the information I've gotten from this thread, CPC's product page, and Raspberry Pi's official Astro Pi part list, I believed I have enough information to get all the part items locally or through websites that ship to USA. Thanks for your help, everyone. Much appreciated!

Next step, build an ISS.

Hi olav216 — though I work for a Canadian reseller, our US sister company Chicago Electronic Distributors now ships from Florida.

I'd be happy to work on a bill of materials for an Astro Pi kit. The ISS might prove a skosh difficult to fit in the 3D printer, though.

bensimmo wrote:Next step, build an ISS.

Yep, one day!

stewart_elmwood wrote:Hi olav216 — though I work for a Canadian reseller, our US sister company Chicago Electronic Distributors now ships from Florida.

Selling from Florida? Shipping will be quick, then! I like your store's offerings so I'll definitely come back again.

I'd be happy to work on a bill of materials for an Astro Pi kit.

Thanks for the offer! I've already started purchasing the parts for my Astro Pi, but I would have bought an Astro Pi component kit from your company if your store had one. The shipping cost would have been much cheaper and practical then.

The ISS might prove a skosh difficult to fit in the 3D printer, though.

As for that, I came across these.
https://www.thingiverse.com/thing:2036874
https://www.thingiverse.com/thing:17114

And bonus link:
https://nasa3d.arc.nasa.gov/models/printable

The AstroPi is an awesome project! (shameless plug) While we are not in the United States (Canada), we happen to have just finished building an RTC / switchboard specifically for the replica AstroPi.

The HAT was designed to eliminate the need to build an adapter board for the 6 external buttons on the AstroPi. It fits between the Pi and the Pi Sense HAT and makes an easy work of connecting up the buttons. Clearance is the main issue with this setup so the design takes into account the difficulty of connecting the camera and the height requirements as well.

The board had quite a bit of space leftover so we added an RTC (because the real one has an RTC) and used the remaining space on the board to break out all of the digital IO pins / I2C / UART / SPI. There is space for an optional ADC - on AstroPi versions of this board it is left unpopulated.

It will be available through our website in the coming weeks in two variations: Replica AstroPi (no ADC) and General Purpose (ADS1015 12-Bit ADC)

Now that we have (finally!) got the http://www.astropicase.com website online and live, Chris has been able to announce that rather nice Switchboard. Even though my contribution was no more than sketching out an idea and saying "make so, number one!", I'm still quite proud of how nice it turned out.

And the full case came out pretty nice, too.

timrowledge wrote:Now that we have (finally!) got the http://www.astropicase.com website online and live, Chris has been able to announce that rather nice Switchboard. Even though my contribution was no more than sketching out an idea and saying "make so, number one!", I'm still quite proud of how nice it turned out.

And the full case came out pretty nice, too.

It sure did Tim!

While $250 is a lot of money for a case for a Pi, if I could justify it to the wife I would buy one.

The $500 cost for a fully assembled unit wouldn't tempt me but I already have many of the parts and all the required experience. I hope you do sell some, you deserve the profit.

BMS Doug wrote:While $250 is a lot of money for a case for a Pi, if I could justify it to the wife I would buy one.

It's obviously a crazy amount of money for 'just a case'. If all someone wants is a box to put a Pi then there are much more economical alternatives (one of my favourites is the SmartiPi, and the element14 Pi-Desktop case looks very promising too) but, and it's a big but, this is what you want if you're into the AstroPi thing. I know that a non-trivial number of people have asked Eben about getting a 'real astropi case' and this is for them. If your school is entering the competition this is a way to get as near to the real thing as possible.

The 3D printed examples I've seen are fun, and some are amazing, but it seems to take a fair bit of work to get a good print and more to clean it up. Unless you get filament for free you could end up paying almost as much to print one. And then you don't get the package of spacers and screws and the Switchboard.

BMS Doug wrote:The $500 cost for a fully assembled unit wouldn't tempt me but I already have many of the parts and all the required experience. I hope you do sell some, you deserve the profit.

Absolutely no reason a hobbyist would want the assembled system; part of the fun is making things, after all. An institution though has different issues and the admin cost of ordering a case, a pi, a HAT, some buttons, finding someone to assemble it and load up the software... it adds up and a single invoice is so much less hassle. And it does after all include those fabulous (and expensive!) APEM buttons; my sample case just provides so much pleasure in the simple act of clicking them. It's the ultimate fidget spinner!

Did you ever find a detailed list, in particular the length of the machine screws?
It sure would be nice to find them in the USA.
http://www.farnell.com/datasheets/2236328.pdf shows nice photos, but some are missing the length and dimensions.

in particular:
- diameter of the push buttons
- height of the extended 26 pin header
- length of the M2 machine screws
- length of the M2.5 machine screws

I’m not too concerned about the length of the jumper wires, but anyone that has info on the above, I’d be grateful if you shared it.

Thank you

I got about 95% of all the parts I needed for my Astro Pi at Tinkersphere. It's a tiny DIY/Hobbyist store in NYC and they do mail order if you can't get there in person. You should verify if the items are in stock however.
https://tinkersphere.com

I say 95%, because a couple of things they do not have is the very tiny screws for the camera mounting and the 4 large 50mm screws to close the case together. For the very tiny screws, I used the next size up and carefully screwed them in as to not break the studs the camera rests on. As for the 4 large screws - Home Depot.

I used the large heavy duty switches on this Astro Pi and it works great. I did have to drill the case to make them fit, but that is not a problem. This.case my friend made last year because at the time I did not have a 3D Printer and I painted it black. Now that I have a 3D Printer, I have printed 2 other cases for future Astro Pies.