VoCore2 Lite – A $4, coin-sized, open-source Linux computer | Hacker News Reader

VoCore2 Lite – A $4, coin-sized, open-source Linux computer

zdnet.com

156 pointscpeterso76 comments

VoCore team on their site[1] said that VoCore2 Lite is "very very close" to cost. I concur, as the heart of that VoCore2 board - MediaTek MT7688AN SoC chip costs between $2.79 and $3.35 (depending on the order quantity) on the Alibaba wholesale site[2].

Congrats to VoCore team to make low cost IoT DIY projects possible and affordable for students.

PS: If you weren't familiar with MediaTek, their SoC chip was the King of Shanzhai culture[3] during early iPhone era.

[1] http://vonger.cn/

[2] https://wholesaler.alibaba.com/product-detail/New-and-origin...

[3] http://www.core-corner.com/Web2/GsMaterialDB/HC_HBRC_9/2014-...

This looks kind of neat, if perhaps not super-accessible.

The pinout diagram has the best named pin in a while, "P0RN" is a classic (http://vonger.cn/?p=2666). :) Btw that page seems to lack a legend, I guess purple is Ethernet.

Yeah, it's Ethernet. P0RN is the negative half of the receive pair for ethernet port 0.

Well yeah, it'd have to be the receive on the Ethernet, it is porn after all.

Yeah I agree on the accessibility. I have version 1, and I haven't even touched it yet. That's in contrast to the RPi, which I immediately began hacking with when I got it. VoCore just seems daunting.

This is cool, but the $4 version isn't comparable with the Raspberry Pi.

The version with connectors and a case costs $39. The Raspberry Pi 3 with connectors and a case is sold for $35 at the first US retailer I found.

On the other hand, you don't always want all the connectors and you have to spend $30. Being able to spend only $4 for the bare minimum is a nice option to have.

Precisely, they can both co-exist and are welcome.

This narrative with click-bait titles of someone having to loose that one has to win is dumb and should die out.

Especially if you want to integrate it with another project so you'll only be soldering on the connections you are using anyway.

It is being compared to the Raspberry Pi Zero, which costs about $5 and it is closer on concept to this VoCore2Lite.

Yes, but the zero already has all the connectors. You plug in the power and hdmi, and it's a fully working machine. This is a board that requires some soldering skills, and it's a really high barier to entry I find.

This isn't intended as a replacement for your desktop computer - most applications don't even require hdmi and afaik the VoCore doesn't support one anyway.

This computer is intended for integration in another device that you want to control via WiFi any maybe some more. It's neither a Workstation nor a Mediacenter.

Sure, but my point is that you can't use this without taking out a soldering iron. It doesn't matter how you want to use it - you just can't, until you solder on some connectors/cables to it. Pi Zero is one dollar more expansive and it doesn't require any soldering.

As someone who really hates soldering things, it's a big barrier to entry.

The makers of this product would even tell you that you aren't in the target market. This is a System On Module, not a Single Board Computer. The later is a "unbox, boot up, and play" experience. The former is "unbox, wire into my existing circuits, standup the board, start coding" experience.

Sure, absolutely, but the title of the linked article is literally "Move over Raspberry Pi, here is a $4, coin-sized, open-source Linux computer", so comparisons to the Raspberry Pi are inevitable.

At the time of my comment, this was also the title of the HN post.

It's only in the headline, so we can probably blame the editor rather than the writer.

"Both versions of the VoCore2 have a power consumption of 74mA at standby, and 230mA at full speed. "

It's great to know how much current it draws, but that doesn't tell me how much power it draws.

"How powerful is your new car?"

"Oh super powerful! It's got 3 inch diameter fuel lines!" ...

It is quite unclear. It seems, however, that it runs at 5 volts, so I guess we are looking at 370mW and 1,15W. Explaining the power requirements clearly would really be important for a product like this.

Since many batteries, especially rechargeable ones, post their mA*hour numbers it makes sense to talk about current.

It says the power supply can be anywhere between 3.2V to 6.0V. So about 1W at full speed and maybe a fifth of that on standby.

I know measuring power in amps is against everything high school physics told us, but it's a really common approach in electronics engineering. They literally do that all the time.

I think a sentence or two later the official site gives an explanation why: lipo battery sizes are measured in mAh, so dividing battery size by current you get hours of operation.

I'm still a noob when it comes to microelectronics, but my understanding is almost every chip runs on 3.3v, lipo batteries are 3.2-3.7v depending on charge level. When they talk about power in amps they assume everyone knows they mean at 3.3v

Still a lot of 5V stuff around. I was working on consumer electronics (tens of millions of units sold) just a few years ago that were still 5V.

It's quoted in current because these systems can operate on a range of voltages, depending on the batteries (or other power sources) used.

And depending on the voltage provided it will draw a range of currents.

In general this is usually true, but simple non-switching regulators are quite common in electronics. They burn the excess energy as heat. In return the power supply has almost no ripple.

Current is much more useful in engineering, because it is more constant for this type of device than power. Power varies with supply voltage while current normally does not.

Other than doing temperature calculations, power is not a very useful metric. And for such calculations you would use a max power rather than average power metric.

If you were optimizing a system for "power" use, it is much easier to work in units of energy than power anyway.

Nope. There is chip looking like PMU on board with at least two output power rails. For VoCore 1 there were two MT3410L converters, one for 3.3V and one for 1.8V. With switching converter total power consumption should be close to SoC power consumption, not depending on input voltage.

Also specification is pretty clear: 74mA wifi standby, 230mA wifi full speed, 5V input. Input voltage range: 3.6V ~ 6.0V.

It is a generalized statement. Very few SoCs have internal switch mode controllers. It is going to either be an LDO, or take a fixed operating voltage. Requirements for such will be specified in current, which is more useful than power.

Module level specs would be irrelevant in engineering because there is little incentive to use something like this, the radio isn't even certified. On that note, get your popcorn ready for when they ship to German backers and customs proceeds to trash them.

> Very few SoCs have internal switch mode controllers.

That's why PMUs are used. Just look at bottom side of the PCB - there are three coils, two of them very close to the chip looking pretty much like PMU.

> It is going to either be an LDO, or take a fixed operating voltage.

No, read specification: 3.6 - 6V.

> Current ... is more constant for this type of device than power. Power varies with supply voltage while current normally does not.

Can you explain why?

The chip is designed to run at a certain minimum voltage, and does so at a certain current. Feeding more voltage does not change its general operation. It throws the excess away as heat and keeps drawing the same current.

You can attach an external circuit to convert to the desired voltage and therefore keep power draw constant. But that takes more space and costs more money.

Throwing away excess voltage as heat is simply easier.

That current consume is actually high compare to typical Mobil SOCI tested. The couple I measured before on PCB power supply point is 2-5 mA (5 volts) on standby - SOC in suspend, LPDDR3 in self refresh but can wake up by wifi activities.

You can ping the ip and it will response. Or you can have telentd running and it will response to user input.

Increasingly, I tend to judge these systems from an availability of documentation for the core SoC. It means if there's a specific problem I can go digging into fix it myself, or that the open source community can dig into the support better in general and you have fewer issues/better support in the first place.

Esp with hobby development, I'd rather save time in having the system documented then $5-10 bucks on the hardware cost.

Hey, it's the VoCore again. I've got one of the first ones... somewhere. It comes exactly as it looks in the photo and was unfortunately far too small for me to solder the headers on to.

I bought one of these things for £5: https://wiki.openwrt.org/toh/unbranded/a5-v11

It has slightly inferior specs, but it has ethernet, USB, and 150M WiFi built in.

These loud footsteps at a distance are from the ESP32 approaching.

(yeah, does not run the Linux kernel but it is going to be quite open this time)

What is it

I think those devices are wasted running a full OS stack for a single purpose, better have a nice baremetal runtime, unikernel style.

The problem being that for most use cases, for the price many of these boards cost, the majority will just go with the Linux option and install something like Yocto.

True... Without Linux, the projects are generally sensors, relays, LEDs. With Linux, "smart" displays, USB webcams, OpenCV.

> With Linux, "smart" displays, USB webcams, OpenCV.

You can do that without Linux, it is just a matter of having bare metal drivers, the only issue is if it is worth doing so from the ROI point of view.

Yes but that is quite more work than "apt-get install opencv", and thar is an incredible barrier to to entry for a lot of projects from a lot of people with less expertise and/or time.

The main selling point of Linux is portability and by that code reuse across a wide array of use cases.

Sure you could build a hardware abstraction layer for different processors and implement drivers on top of that, but you won't get the same traction/networking effect of Linux anytime soon.

Same goes for software stacks (TCP/IP, USB, WiFi, file systems, etc) which have been running on billions of devices before if you use linux.

The overhead of using Linux is in the range of 1-2MiB [1] so once your application requires external Ram because it doesn't fit the on-chip SRAM, you might as well use Linux.

[1] http://www.emcraft.com/stm32f429discovery/what-is-minimal-fo...

Agree, hence why I mentioned that for the price those boards cost, going Linux might be what the majority will do.

On the other hand I look at chips like the ESP32, and given that my coding skills started on Z80 computers, 512 KB is more than enough and actually more fun to use.

Given the set of high level programming languages I was using in those days, there is plenty of juice to squeeze out of those types of MCUs.

Quantities may be limited but ESP32 boards are "here." Bare modules are a little under $10.

https://www.adafruit.com/products/3320

https://www.adafruit.com/product/3269

https://www.sparkfun.com/products/13907

$5 buys you Raspberry Pi Zero: 512MB RAM, 1GHz CPU, MicroSD slot, 40 I/O pins, mini-HDMI, microUSB.

just out of curiosity: where would I be able to get one? they seem to be perpetually out of stock (at the $5 price point).

Says in stock on Adafruit https://www.adafruit.com/product/2885

But no WiFi - that's the big difference here imo.

I just (10 mins ago) ordered one from Pimoroni. 6.50GBP including the cheapest domestic shipping option. That's 8.14USD.

There's no way to save on shipping by buying multiple units, as the limit is 1 per customer.

I'm guessing shipping (the padded bag plus postage) costs them about 80p, so in reality I paid about $7, not $5. About $1 of that is tax.

How do you use it without storage? (can you use it without the connectors?)

If there was a mini-sd I could imagine: put some image on it that knows your wifi, ssh in to it. So if i manage to solder in power and plug in my spare antenna here it might work. Probably you can even just cut some wire of the right size and program it next to your router, my directional antenna is not much more (just some tin can for the directional part).

It has 8MB of NOR storage. Sure, you aren't putting Debian on there, but it'll take your wifi creds.

Ah ok, great.

I think the intention is that you run something like DD-WRT on it. 8MB of storage is a bit tight even for DD-WRT however, if I was looking at these boards I would seriously consider splurging on the $12 model to avoid the low storage headaches.

If I were building a hundred or more devices I'd do the work to make the $4 version work, but for a one-off it's not worth the headache.

The PCIe option is surprising. I'm not sure what I would use it for, but it does open up some unusual possibilities.

> 8MB of storage is a bit tight even for DD-WRT however

8MB of NOR flash is totally standard for a vast majority of consumer routers.

OpenWrt/LEDE will happily fit on 8MB with around 4MB available as /overlay (e.g. for additional packages or data).

> The PCIe option is surprising. I'm not sure what I would use it for, but it does open up some unusual possibilities.

You can use PCI-e for 5GHz WiFi (most common use for PCIe on this SoC line). You can also buy SATA controllers or Gigabit Ethernet in mini-PCIe form factor.

Most UMTS/LTE modems in mini-PCIe form factor are actually only utilizing the USB pins in a mini-PCIe slot, so you don't actually need PCIe for those.

Can anyone recommend a device whihc has Wifi and supports MONITOR mode?

I can't find any information on this device, but essentially I'm looking for something which:

- Supports WIFI to connect the device to a network

- Supports WIFI promiscuous mode _ALSO_ so that I can listen to PROBE requests from devices in the area

- Linux..

Seems like a really hard search?

Maybe find one that can use a USB wifi w/ promiscuous mode? I bet you can probably find a small one of those

Have you tried searching for the use-case instead and seeing what hardware other people use.

I've seen somewhere battery powered WiFi sniffing units, possibly on CCC.de or mentioned in a blackhat conference video.

So specifically most comparable to a Raspberry Pi Zero? At least price-wise, but not peripheral-wise?

Huh, looks like this is MIPS not ARM:

http://www.datasheet4u.com/datasheet-pdf/MEDIATEK/MT7688AN/p...

Just "bought" one from the indiegogo campaign.

Does anyone know when will they be shipping? No hurry, just want to know when to shedule in my agenda to check whether it's shipping or not.

I guess you're not able to run mainline kernel on it?

My experience with mediatek is that they are awful at publishing their linux kernel source code.

Generally, don't touch anything with mediatek or allwinner if you want it to work at the end of the day. Their driver support is very bad. Funny personal story, I turned down a contract almost four years ago that would have involved getting 3D running on an Allwinner based board. Four years later and CHIP is demoing an "Alpha" of 3D on Allwinner.

Meanwhile even hardware accelerated 3D and video decoding works on the Broadcom SoCs in the Pi, and has for years.

Mediatek and Allwinner are cheap, but useless.

Don't know about mainline, but there is some OpenWrt support for other boards with the MT7688 e.g. https://wiki.openwrt.org/toh/seeed/linkit7688

Looks like it might be (partially) supported:

https://github.com/torvalds/linux/search?utf8=%E2%9C%93&q=MT...

Is there any on board ADC/DAC? Using this for data acquisition would be great.

Does the PCIe support mean you could use NVMe ssds? Storage is the biggest problem with most single board computers as it usually goes over USB or uses unreliable SD cards.

Are there cheap NVMe cards? My only experience with NVMe is in the context of ~$250+ SSDs... which seems like an odd pairing with a $4 processor.

Even more so if you consider that the SSD likely has a more powerful processor than the VoCore.

And PCIe 1.1 is going to bottleneck the SSD.

I'm waiting for an "open" SSD for which you could modify the firmware to include your own little program stack.

Just run your entire little sensor/project out of the HDD itself.

http://www.openssd-project.org/

Nice, thanks.

Beginning at 54€ for 128GB according to geizhals: http://geizhals.eu/?cat=hdssd&xf=4832_3&sort=p

I couldn't find any reference to PCIe in the indiegogo campaign. Maybe it's a typo in the zdnet article?

Edit: nevermind, it's in the official site: http://vonger.cn/?p=2652

Apples and oranges.

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