A quick Model A show and tell from Adafruit

We sent our friends LadyAda and PT at Adafruit one of the first production sample Model A boards – as well as stocking them at Adafruit when we go to full production, we had a feeling that they might like to try to get in there early with some add-on development work. It’s just arrived in New York, and they’ve taken some video and pictures. We thought you’d like to share.

PT also took some pictures which are a bit better than the wobbly cell phone one we showed you a couple of weeks back:

Model A product sample. Click to embiggen.

Model A, back view. Click to enlarge.

In other news, Eben picked up his IT Pro IT Leader of the Year award yesterday. We refused to follow him back to the station because we thought it was funny.

Updated to add: Pete Wood from DesignSpark, who we also sent a board to, sent me some video of his own about 45 minutes after I’d first published this post. His video is below; he’s also written a post about the Model A¬†with some comparison photos over at DesignSpark.


MattPurland avatar

Really can’t wait to get one of these, purely for the lower profile of the hardware! Shame it only has 256mb RAM though :(

Norman Dunbar avatar

Hi Matt,

it could have been worse, they only had 128 Mb when first designed. Anyway, My Pi has “only” 256 Mb RAM and it’s doing fine.

My Sinclair ZX-81 has 1 Kb. My Spectrum 16 Kb and my QL 128 Kb. Who needs M when you have K? ;-)

What do you do to maximise the abilities when you only have small RAM? Learn assembly language! [ducks and runs]


poglad avatar

Many a true word spoken in jest!

MattPurland avatar

If I’m honest it probably won’t make much of a difference, but it’d be nice for it to be uniform across all models. I’m sure I can live it!

Nicholas Green avatar

Yes, but did your ZX-81 or Spectrum output 108p video?

XTL avatar

Spectrum didn’t do 108p, it did 192p and QL even did 256p! :)

Foxdie avatar

Can we get a height profile photo too? :)

Also, I realise this is too little too late, but would have been handy if this had a standard USB header (as on 99% of motherboards) so we could shave off another 1/2″ from the side.

JamesH avatar

Nice idea. But not on this board I’m afraid, as you say, a bit too late!

PeteWood@DesignSpark avatar

I’ve added a side on image against the Model B to my Blog, so you can get some idea of the Model A height.


liz avatar

Thanks Pete!

meltwater avatar

Thanks i was going to ask about that. Should fit nicely.

Adam Haile avatar

Is there an actual difference between the PCB of model A and model B or is model A just not populated with the network jack and has less RAM?
Would it be theoretically possible to solder on our own Ethernet port and get it working or would the firmware or something else prevent that?

Not trying to jut get a cheaper Model B, just curious if there would be an upgrade path in the future if desired.

JamesH avatar

Also, there is no ethernet chip on the A, so not possible to just add a connector.

Adam Haile avatar

Right you are… now that I look at Model B vs the Model A pics I can see where that chip is supposed to be. I had assumed that since it used an SoC it was ALL inclusive; USB, ethernet, video, etc.

Guess you *could* solder on the ethernet chip too :P That would be a nightmare!

Guess WiFi would always be an option :)

Thanks for the clarification :)

Gert avatar

It is a TQFP(Thin Quad Flat pack) they are easy to solder*. I just don’t understand why you would want to do that. You just get nearly a B for a lot more cost and effort.
*Trick is to ‘wipe’ you solder iron along it starting with a minuscule bit of solder: done! Make sure you use a lot of flux before you start. Then if pins are still together post process with some solder braid.

mahjongg avatar

Gert, you are mostly right, especially if you use a hollow tipis quite easy, but there is one problem in this case, and that is the ground tab underneath! There is no way you can reflow it without some solderpaste and an oven, or at a minimum a hot air gun.

You are completely right about the need though, if you understand that this chip contains both the USB hub, and the ethernet chip you should understand that there is no reason to solder the chip back on a model-A board.

Passie avatar

Are those holes of the missing ethernet port usable as a third mounting hole?

Montekuri avatar

I’am in Brazil and I cannot access the Adafruit webpage.

ladyada avatar

that’s odd! we have customers from brazil and many friends who visit our site!

Montekuri avatar

Now I see. I cannot access Adafruit webpage from my job, where we use static IP.
At home I can access the Adafruit webpage. At home we use dhcp.
I have to research more about this issue.

Brian Smith avatar

Will Chinese New Year have any impact on availability?

clive avatar

Not in Pencoed, though I hear Cardiff has a good CNY party ;)

Duncan avatar

Without an ethernet chip it won’t be possible to use a USB wifi chip?

nelson avatar

Without an ethernet chip you will have to connect an usb adapter to the raspi if you need network/internet, you can use wired and wireless adapters without any problem. The chip they took out is what you find inside those adapters, in the raspi case they just soldered it to the board, it was still internally usb. also without this chip the power consumption of the raspi drops significantly so some previously unstable/non-working usb peripherals may now work has more current is available to them.

Duncan avatar

Ok, thanks!

Russ Nelson avatar

Wow! Only 100mA! This looks awesome for our Hudson River water quality monitors. I’ll totally given LA and PT an invite when we deploy one in the city.

I don’t suppose we could pre-order some, could we, LadyAda?

carlos avatar

is it possible to connect a second usb socket to the board?

nelson avatar

It won’t work, the SOC used only supplies 1 USB port, on model A that port is wired directly to the USB connector, on model B that port is connected to a chip that works like a USB hub + ethernet combo onboard

carlos avatar

ok thanks, i thought that missing chip was only for the ethernet

omenie avatar

Liz – can I get one? It would be helpful … I have money and all that.

liz avatar

I’m really sorry – I know what you’d be doing with it, and I’d love to be able to send you one. But they’re in *enormously* short supply – they’ll be available on the open market very soon, but right now we simply don’t have any more to offer.

omenie avatar

It was worth a try! As soon as they are freely available I’ll get a few in – it’s definitely the right platform for me – just enough memory, *excellent* price point, and less tall so it can be squished into even smaller spaces.

Peter Green avatar

If you are really desperate you can always take a model B, remove the USB hub with ethernet chip and fit the links that hook up the SoC direct to the ports.

Knickers avatar

I had an observation. The usb port pokes out a lot form the side of the board. I know that it is in the same distance as the model B, but now it looks like there is a set of unused pins farther in that can be used. Is this something that a user can do? Are the second set of pins also connected to the usb controller?

liz avatar


Ate avatar

I agree it is sticking out way to much, but I got rid of it by desoldering the connector and replace it by pins.
On that pins you can stick a normal cable used on motherboards.

I had to desolder the yellow and blue ones too because in 2010, when I made my contraption, I did not know the creditcard size was in fact a creditcard with extensions….

Jim Manley avatar

Can’t wait for our school districts to be able to buy “mass quantities” of Model A boards (in Conehead parlance) which I’m assuming will be “launched” on February “29th”, 2013 and delivered starting on April 1st, 2013 ;)

Buy stock in USB 2.0 hub manufacturing companies, since it will be difficult to run Model A boards as desktop-style full-up computers with only one USB port (especially if you want to plug in a WiFi dongle), and if the Model A is only half as popular as the Model B … we’re still talking somewhere North of half a million boards a year at the current Model B uptake rate. What will be really interesting is to see if Model A availability puts a dent in Model B demand. My bet is that it will be hardly noticeable and primarily determined by how limiting the 256 MB proves to be for educational users, along with demand from users with lightweight-memory-use headless applications. That could include lots of educational uses such as robotics, mobile/battery-based projects (due to low current draw) on balloons/aircraft/vehicles, and various and sundry other embedded projects such as lightweight media-server/home-theater systems.

The future’s so bright, I gotta wear shades … or just close the blinds so I can see what’s on the gorgeous 80-inch HD display I’m wishing Santa would bring (I take it that the stock certificate for a company that specializes in bituminous products I got in a Christmas card from him is not a good sign … ):

tzj avatar

Would ‘LAN run’ (BCM-GPIO 6) be useable on the model A?

tzj avatar

I assume a yes to this then…

jim avatar

Does the model A have the pins for the camera module (if there really is such a thing)

toxibunny avatar

Yes it does, and haven’t you seen the post/pics/video of the camera module..?

jim avatar

In all the pictures it looks like the pins are missing with open copper holes where the should be. Maybe i am missing something.

mahjongg avatar

Yes, you are missing something, I assume you are referring to the two rows of holes (one one hole shorter) that begin in-between the RCA and the 3.5mm jack sockets., or perhaps the two rows of four pins located below the GPIO connector, Those have nothing to do with the camera module!

The camera module will be connected to the “flexcable connector” located in-between the HDMI and ethernet ports, and it is available on every board ever made, and on the model A.

Another very similar connector located above the SD-Card will in the future be useable to connect LCD panels.

jim avatar

Thanks for clearing that up. So what the the missing pins between the RCA and the 3.5mm jack sockets?

mahjongg avatar

JTAG test headers. http://en.wikipedia.org/wiki/Joint_Test_Action_Group

Not useful to a user in any way.

George avatar

liz, i want to buy some Pis now at Christmas. (Model B)
should i buy them now , or wait for the “final” version of the model B as you mentioned about a month ago in the forum …???

JamesH avatar

There are going to be no major changes to the Model B in the foreseeable future, so I’d buy now.

George avatar

ok , thanks!

nelson avatar

just curious… what minor changes are you expecting?

JamesH avatar

Well, could be anything- minor changes to the PCB to help with manufacture would be a good example, as with the rev 1 to 2. Also minor bug fixes to the board. But the SOC, memory won’t change. Much the same as any computing device – the PCB undergoes revisions through its lifetime.

bigfoothippy avatar

Like with the original BBC Micro which had it’s board revised to at least version 7 (Which I had).

Nathanael Smith avatar

Would be great if it could oneday have its own PCB to make it even smaller.

general Lee otto avatar

these “pictures” illustrate the EVIL that is JPeG.

there might have been quality images but they’re NOT here. Please save to PNG24 or PNG32 for interweb use

JamesH avatar

In your opinion.

Igor avatar

I wan to order simple model A ,for croatia..but how much would i have to pay extra for shipping and customs? :S Please help

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