Sourcing Astro Pi parts from USA-based websites/stores

All things Astro Pi: the competition, the hardware and programming

13 posts
by olav216 » Fri Jun 02, 2017 2:54 pm
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-comp1/astro-pi-component-kit-budget/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/astro-pi-flight-case/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-Lockless-Momentary-Switch/dp/B01E6SBB5E/ref=sr_1_15?s=industrial&ie=UTF8&qid=1495308626&sr=1-15&keywords=momentary+push+button+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
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by BMS Doug » Fri Jun 02, 2017 3:14 pm
  • 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.
Doug.
Building Management Systems Engineer.
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by BMS Doug » Fri Jun 02, 2017 3:33 pm
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.
Doug.
Building Management Systems Engineer.
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by olav216 » Fri Jun 02, 2017 3:53 pm
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
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Joined: Mon May 01, 2017 12:36 am
by BMS Doug » Fri Jun 02, 2017 4:00 pm
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.
Doug.
Building Management Systems Engineer.
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Location: London, UK
by KMyers » Sun Jun 04, 2017 5:08 pm
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
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by bensimmo » Sun Jun 04, 2017 6:45 pm
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/
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by olav216 » Mon Jun 05, 2017 11:38 am
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!
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by olav216 » Mon Jun 05, 2017 12:01 pm
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!
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by bensimmo » Mon Jun 05, 2017 4:11 pm
Next step, build an ISS.
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by stewart_elmwood » Mon Jun 05, 2017 4:16 pm
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.
I work at Elmwood Electronics — Canadian Source for Raspberry Pi, Adafruit, Arduino, SparkFun and more. Local pickup available in Toronto ­— https://elmwood.to/
  (a.k.a. scruss for non-work things)
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by olav216 » Tue Jun 06, 2017 5:06 pm
bensimmo wrote:Next step, build an ISS.

Yep, one day! :lol:

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
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by BCR Chris » Mon Jun 12, 2017 6:36 pm
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)
Chris @ BC Robotics
http://www.bc-robotics.com
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