Raspberry Pi Zero

Discussion and questions about boards that can run MicroPython but don't have a dedicated forum.
Target audience: Everyone interested in running MicroPython on other hardware.
poly
Posts: 5
Joined: Thu Nov 26, 2015 9:07 pm

Re: Raspberry Pi Zero

Post by poly » Sat Nov 28, 2015 6:35 pm

pfalcon,

I'm not disputing that the pyboard is worth its cost, nor am I underestimating the time, effort, cost and commitment needed to not only create the first release but to continue supporting it into the future. Its a fundamental problem with the Open Source type model.
riklaunim wrote:If you use such chip you would want to use USB devices, a display and more.
£30 (ish) is fine for a development project, or a niche application, but what I assume everyone who likes the uPython concept would like to see is wider use / recognition of its success / an even larger community that safeguards its longevity. Now obviously one way to fund that is through selling boards, but if you can do 99% of the stuff with a £3 board and the heavily supported Pi community that might start to become harder to "compete" on the board front.

I'm a user of a PiBoard (I dabble), but I have to be honest if I was starting a project today I'd have a very real dilemma about which way to go with Zero v PiBoard. I can also see that a Pi Zero port potentially removes one of the few sources of revenue for micropython by letting this cool stuff be used on a third party cheaper board.

The sorts of really simple projects I play with (things like temperature loggers) are crying out for a "disposable" priced board with very few features. I'd happily buy them in tens to get them "cheap".

@riklaunim:

"If you use such chip you would want to use USB devices, a display and more."

I see why you say that, but actually if all you want to do is say log a temperature every 30s and open / close a relay depending on the result and perhaps turn an LED on/off to show a status then you don't need any of that fancy stuff. But if you want to do that at 50 locations, then £3 is a lot more attractive than £30!

pfalcon
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Re: Raspberry Pi Zero

Post by pfalcon » Sat Nov 28, 2015 7:09 pm

poly, so you just enumerated problems, and offered zero possible solutions. So, what's your argument? You see, any car is almost a helicopter, but bastard vendors don't include propeller and don't allow to turn engine axis up. You're welcome to treat Pi as such (car, not a helicopter) or spend some time and provide anyone with drawings and instructions how turn theirs from one to another. If you expect someone else to provide such stuff to you instead, I tried to explain my IMHO why this isn't going to happen - soon, or at all. Not because someone doesn't want to give it to you, but because people have better things to do.
Awesome MicroPython list
Pycopy - A better MicroPython https://github.com/pfalcon/micropython
MicroPython standard library for all ports and forks - https://github.com/pfalcon/micropython-lib
More up to date docs - http://pycopy.readthedocs.io/

nekomatic
Posts: 13
Joined: Thu May 08, 2014 9:31 pm

Re: Raspberry Pi Zero

Post by nekomatic » Sat Nov 28, 2015 8:25 pm

poly wrote:actually if all you want to do is say log a temperature every 30s and open / close a relay depending on the result and perhaps turn an LED on/off to show a status then you don't need any of that fancy stuff. But if you want to do that at 50 locations, then £3 is a lot more attractive than £30!
To be honest if you really only want to do that, you might as well use something like a PICAXE, or a chip-only Arduino-compatible, or any other cheap microcontroller. When I first heard about the Pi Zero, 'wow, what about running MicroPython on bare metal on that?' was also one of my first thoughts, but if you step back a bit and consider the issues such as the Broadcom chipset and the lack of low power support I'm sure it makes more sense to focus any development effort on a port to a low cost board that's already under way, such as the ESP8266.

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marfis
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Re: Raspberry Pi Zero

Post by marfis » Sat Nov 28, 2015 9:45 pm

poly wrote:actually if all you want to do is say log a temperature every 30s and open / close a relay depending on the result and perhaps turn an LED on/off to show a status then you don't need any of that fancy stuff. But if you want to do that at 50 locations, then £3 is a lot more attractive than £30!
I'm with you with that point. Exactly for this purpose a sub 3$ board that runs uPy would be really nice and I think would be achivable as well. Besides other advantages such as boot times, setup times, security updates, power requirement and whatever else comes with complex OS's.

Not everybody needs complex application or networking stuff. A lot of people just want to play with neopixels/sensors/low power. And that just is so much more fun using uPy than Arduino.

So really - The uPy universe is at the moment missing this piece of HW.

I did an effort in porting the L151 cortex M3 to uPy and made a custom board that't the size of the popular adafruit GEMMA board.. But even if I was producing 10k units I'd probably still be over 5$ in cost to produce, leaving not enough margins to really sell the board much below 10$.

Maybe today I'd cosider using a Cortex M0+ and with the frozen bytecodes the RAM/Flash requirements may even fit onto this little controller.

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dhylands
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Re: Raspberry Pi Zero

Post by dhylands » Sun Nov 29, 2015 12:06 am

The thing about the Pi is that it works great for some types of applications and not others.

It has limited I/O (one SPI, ine I2C, one UART, and some GPIO).
It doesn't have great timer support, it doesn't have any DACs and it doesn't have any ADCs.
It has great graphics support, and decent ethernet and USB support.

So the fact that its only $5 doesn't help if you have to add a bunch of support circuitry to interface with what you want. If you can use it more or less as is then its great.

Its all about tradeoffs and figuring out what compromises you need to do to make a given board work for a given application. If you're happy with a given configuration and it meets your needs, then go for it.

poly
Posts: 5
Joined: Thu Nov 26, 2015 9:07 pm

Re: Raspberry Pi Zero

Post by poly » Sun Nov 29, 2015 4:02 pm

pfalcon wrote:poly, so you just enumerated problems, and offered zero possible solutions. So, what's your argument?
I wasn't trying to have an argument I was trying to have a discussion. You seem to have assumed that I "...expect someone else to provide such stuff to you instead..." - I made no such presumption, I simply began a discussion about what seemed like an "obvious" question to ask, and see if anyone smarter than me has already given it some thought. It seems a few other people also thought it was a credible question to ask. I apologise if this has in someway caused you offence.
nekomatic wrote:To be honest if you really only want to do that, you might as well use something like a PICAXE, or a chip-only Arduino-compatible, or any other cheap microcontroller.
Well I could, but the flexibility and speed of working with Python is highly attractive.
When I first heard about the Pi Zero, 'wow, what about running MicroPython on bare metal on that?' was also one of my first thoughts, but if you step back a bit and consider the issues such as the Broadcom chipset and the lack of low power support I'm sure it makes more sense to focus any development effort on a port to a low cost board that's already under way, such as the ESP8266.
Indeed and I admit that whilst I was vaguely aware of an ESP8266 port I hadn't realised it was particularly low cost. I've just done a bit more reading on it and it does sound as though it is potentially what I am after. It would actually have a number of advantages over a Pi Zero.
dhylands wrote:The thing about the Pi is that it works great for some types of applications and not others.

It has limited I/O (one SPI, ine I2C, one UART, and some GPIO).
It doesn't have great timer support, it doesn't have any DACs and it doesn't have any ADCs.
It has great graphics support, and decent ethernet and USB support.

So the fact that its only $5 doesn't help if you have to add a bunch of support circuitry to interface with what you want. If you can use it more or less as is then its great.
I think those are useful points to make (I don't think the Pi Zero has any ethernet on board which is a shame); having spent a bit more time looking at what is involved in getting stuff working on the Pi Zero it seems that there is probably some clever marketing going on too. £4 seems to good to be true, and actually it is. You need an 8GB SD card £3 ?. You need a power supply £4 ?. If you want to connect anything to the GPIO etc you need the headers £1? If you want to use Wifi you need a USB adapter (£6? and a mini-standard USB cable (£3?) (not to mention HDMI cable etc to actually use its full potential). so not far off the cost of the WiPy? And with a "messier" and larger footprint for any installation. If I understand correctly that the ESP8266 will offer Wifi enabled simple processing for sub £5 then it may well be it is (or will be) doing exactly what I was seeking...

mianos
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Re: Raspberry Pi Zero

Post by mianos » Sun Nov 29, 2015 9:33 pm

The ESP has solid micropython support, simple timer that's easy to use, an ADC, SPI, I2C, UART, 1wire, interrupt driven GPIO, wifi and many have USB if you need it.
If you want to interface, it's a much better choice to me.

The new rpi is super cool but I have no idea what for.
If they were in shops down here in Sydney I would have got one already. :)
I think most of the first batch will be sitting on the shelf if people didn't buy the special cables.

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bmarkus
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Re: Raspberry Pi Zero

Post by bmarkus » Mon Nov 30, 2015 7:16 am

Regarding RPi connectivity you have also the 1-wire Dallas/Maxim interface. 8GB SD card is needed for Raspbian, but e.g. piCore LINUX runs fine with an 512M card (if you find any). Zero has no Ethernet and many apps even do not need video connection. You can save the HDMI cable, but you have the power consumption of GPU.

There is one unique feature, you can get a high frequency I mean up to cca. 200MHz output signal at GPIO pin. In software using DMA you can generate special modulation schemes like FM stereo signal with RDS in the FM band, PSK signals (WSPR) for ham radio shortwave propagation test, and so on.

Zero is a nice board if you are working with RPi similar to the more expensive compute module (CM) and want to reuse existing code base. Bare bone MicroPython is still a question for me not only from investment side.
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pfalcon
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Re: Raspberry Pi Zero

Post by pfalcon » Mon Nov 30, 2015 4:33 pm

poly wrote:I wasn't trying to have an argument I was trying to have a discussion. You seem to have assumed that I "...expect someone else to provide such stuff to you instead..." - I made no such presumption, I simply began a discussion about what seemed like an "obvious" question to ask, and see if anyone smarter than me has already given it some thought. It seems a few other people also thought it was a credible question to ask. I apologise if this has in someway caused you offence.
It did not, but I don't see what other positive outcome of such discussions can be except "time to start coding!". Sorry if my short-circuiting to it caused offense to you.
Awesome MicroPython list
Pycopy - A better MicroPython https://github.com/pfalcon/micropython
MicroPython standard library for all ports and forks - https://github.com/pfalcon/micropython-lib
More up to date docs - http://pycopy.readthedocs.io/

Damien
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Re: Raspberry Pi Zero

Post by Damien » Tue Dec 01, 2015 10:05 am

The RPi Zero and similar boards are pretty cool, and they definitely have their place. They also do overlap with pyboard (and other MCU boards) for some applications.

But a dedicated MCU will always have the advantages of lower power consumption, sophisticated IO peripherals, bare metal dererminism, and lower cost (in volume for custom boards). And don't forget that you can build your own MCU board from the ground up and put uPy on it, whereas with a RPi you are locked into the chipset.

MicroPython is an evolving piece of software with a growing community that can and will adapt to future hardware and technology. Learn the software and the language and it'll be useful for many years to come. RPi Zero is a single piece of hardware that won't take long to be outdated and replaced (although learning Linux to use it is valuable and transferable).

Regarding a port of uPy to RPi, I don't have resources for this, but if other people do then it would be good to coordinate.

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