The MagPi Magazine - Aimed at learners - Printed edition Kickstarter

I hate to be so negative, but the writing in this magazine seems to be getting worse. I have read every one so far, but in the most recent one there seems to be a number of things that just leave the user hanging or have obviously been written by someone who is an expert in what they are doing, but can't convey that information properly to a beginner.

I did look at the Kickstarter on this, but couldn't justify it on the grounds that better information is either available freely on the web, or via one of the many books popping up recently that are cheaper than the bound set of these magazines.

I was however happy to see the Ciseco Eve Kickstarter get funded and I have my board from them already :-)

Steve

I hate to be so negative

Yea it's not like you have a history of that in Rapberri Pi forums or anything. Oh, wait a minute.

John Beetem wrote: You can have upper NPN drivers provided that you can get the base voltage higher than the emitter voltage.  The L298 diagram doesn't show the details of the AND gates that drive the upper NPNs.  I suspect they convert TTL input levels to "Vs".

You're right. I found a data sheet for the L293 and the first stage transistors on the motor drivers are tied to the motor supply.

I hate to be so negative

Yea it's not like you have a history of that in Rapberri Pi forums or anything. Oh, wait a minute.

John Beetem wrote: You can have upper NPN drivers provided that you can get the base voltage higher than the emitter voltage.  The L298 diagram doesn't show the details of the AND gates that drive the upper NPNs.  I suspect they convert TTL input levels to "Vs".

You're right. I found a data sheet for the L293 and the first stage transistors on the motor drivers are tied to the motor supply.

Gary Stewart wrote:

 

I hate to be so negative

 

Yea it's not like you have a history of that in Rapberri Pi forums or anything. Oh, wait a minute.

Another fan of my work :-)

The thing is, what gap is this magazine filling ? None as far as I can see. Taking the 'H' bridge article above, I can't see what it is supposed to add. At the end of the article, it goes on to say that next edition, there will be another way to drive a motor with cheaper transistors etc. So in the mean time, do I wait or just hit google and work it out for myself with the myriad of resources available on line. Will next month it illustrate something else and the go on to promise and even better method the next month? At least in the days of Spectrum User, you got a complete program to type in (albeit with printing errors to make it that bit more interesting!) so you could have some gratification there.

Also, i'm not sure what the point is of doing two articles on programming languages (Cecil and ADA) that are hardly in the sphere that the Pi is aimed at. That smacks to me of padding out.

So, do I take my £25 and get 8 whole copies of a magazine that stretches to about 32 sides an issue, or do I spend that on another Pi, or do I spend it on one of the many interfacing options springing up and a good book - these should provide immediate reward and be a much better prospect in the long run.

It is something that can be levelled at most magazines now, which is why I don't buy any. I also object to the large amount of coverage the Foundation have given them when there are countless other people working away on different projects that hardly get a mention. It's been the same with the Pibow people too, massive amounts of coverage and 'Oh look, our kickstater is funded'

Steve Read wrote:

 

The thing is, what gap is this magazine filling?  None as far as I can see.  Taking the 'H' bridge article above, I can't see what it is supposed to add.  At the end of the article, it goes on to say that next edition, there will be another way to drive a motor with cheaper transistors etc.  So in the mean time, do I wait or just hit Google and work it out for myself with the myriad of resources available on line.

JMO/YMMV:

I haven't read MagPi Magazine myself, but I've read good reviews of it.  Its audience is new RasPi users who don't have strong technical backgrounds and don't know where to start.  Old timers like yours truly are excited by RasPi because of its ridiculously low cost for a GNU/Linux "box" and we know what can be done with such a board: basically the same things we did with $295 boards five years ago, but now the penalty for smoking a board is the cost of a good dinner.  But we're not the official RPF target audience.  The target audience is young pups who don't know what they're doing but have boundless enthusiasm and "Insatiable Curiosity, which means they ask ever so many questions" [Kipling].

MagPi is a way to get them started.  Like all magazines and wikis that depend on unpaid contributors, quality varies and at some point a magazine needs to decide if it should follow a strict periodic publication schedule or only publish when they have something worth saying.  Personally, I find most printed matter becomes obsolete pretty quickly and a well-edited wiki with an enthusiastic community behind it is a much better use of 21st Century resources.

Googling things is problematic.  If you know exactly what you're looking for and have enough knowledge to filter out the high noise content it can be very effective.  If you're a newbie, it's hit and miss -- mostly miss.  I generally start tech searches with Wikipedia, which often has excellent technical information though not always -- quality depends on whether there's someone (preferably plural) fanatically interesting in the topic who takes the time to polish the article.  I go to Wikipedia to fill in gaps in my knowledge, not to learn something big like logic design or circuit theory from scratch.

I haven't looked at it much, but in general as a suggestion maybe they need to get the magazine and any blog content vetted by someone senior before they publish. I've just spotted on the raspberrypi.org site that someone has published a relay controller connected to mains, but the creepage (?) distance is less than a millimeter on the stripboard between the relay switch COM pin to the ULN2003A ic (left unsoldered on the stripboard). I only noticed this because I've used a similar relay pinout in the past. I would respond but I don't think I've ever registered at their site. I will  leave a comment on the linked blog however (here), maybe the author can indicate it is not for mains.

I think it fills the niche of people who like things in a magazine format. For sure people are doing great things on blogs and on YouTube as well. I personally have not seen the foundation pushing The MagPi especially hard, but I only read the RPi forums, not their blog or follow their in person goings on or other media they do. But I wouldn't be surprised if they did, it seemingly holds some weight to say "There is a magazine dedicated to our product" even if it is nothing more than a differently formatted type of blog.

As to the wiki, unfortunately, with the unofficial, but still definitive RPi wiki, it is very out of date in many areas. It seems about the last thing people do is decide to go back and edit the wiki when things change and there is certainly a dedicated community around the RPi so I do not think that is the part that is lacking. My main reason for not editing the wiki much is that I feel I am not qualified to edit what is essentially a definitive source of information.

Please do register for the forums and contribute, especially information you feel is important. The forums are one of the main places people look for information as far as I can tell. I for one post on there for no other reason than to get feedback from better informed folks like yourself, it is really helpful.

I've left a comment on the blog and also just tried the raspberrypi.org, it seems I only needed to write a name and e-mail address. I don't see it published, but I guess it is moderated first.

Blake Girardot wrote:

 

As to the wiki, unfortunately, with the unofficial, but still definitive RPi wiki, it is very out of date in many areas. It seems about the last thing people do is decide to go back and edit the wiki when things change and there is certainly a dedicated community around the RPi so I do not think that is the part that is lacking. My main reason for not editing the wiki much is that I feel I am not qualified to edit what is essentially a definitive source of information.

I also hesitate to update the RasPi wiki if I'm unsure about my information, but if I think it's important I'll edit and include caveats ("One user has found that...") and links to the original discussions.   It's really nice to have a single starting point for RasPi questions, and the wiki is the obvious place for this.  Most of my contributions to the wiki have been troubleshooting hints.  It's so much better to be able to tell a newbie to "first check the Troubleshooting Wiki (link)" and get 90% of the problems taken care of instead of having to answer FAQs.  Sometimes FAQs indicate that the Wiki's answer is poorly worded (or formatted) or hard to find, in which case fixing a couple of lines can be quite beneficial.

I haven't read MagPi Magazine myself, but I've read good reviews of it.  Its audience is new RasPi users who don't have strong technical backgrounds and don't know where to start.  Old timers like yours truly are excited by RasPi because of its ridiculously low cost for a GNU/Linux "box" and we know what can be done with such a board: basically the same things we did with $295 boards five years ago, but now the penalty for smoking a board is the cost of a good dinner.  But we're not the official RPF target audience.  The target audience is young pups who don't know what they're doing but have boundless enthusiasm and "Insatiable Curiosity, which means they ask ever so many questions" [Kipling].

 

MagPi is a way to get them started.  Like all magazines and wikis that depend on unpaid contributors, quality varies and at some point a magazine needs to decide if it should follow a strict periodic publication schedule or only publish when they have something worth saying.  Personally, I find most printed matter becomes obsolete pretty quickly and a well-edited wiki with an enthusiastic community behind it is a much better use of 21st Century resources.

 

Googling things is problematic.  If you know exactly what you're looking for and have enough knowledge to filter out the high noise content it can be very effective.  If you're a newbie, it's hit and miss -- mostly miss.  I generally start tech searches with Wikipedia, which often has excellent technical information though not always -- quality depends on whether there's someone (preferably plural) fanatically interesting in the topic who takes the time to polish the article.  I go to Wikipedia to fill in gaps in my knowledge, not to learn something big like logic design or circuit theory from scratch.

Hello John,

I don't think we're too far apart on this :-) I think the Pi is a great catalyst for those of an inquisitive nature and has a great number of possibilities. But those with that sort of mind normally like something to get their teeth into straight away. Whilst I'm all for delayed gratification in most cases, I just think that £25 spent on one of the current Pi books and a starter book on electronics would be £25 better spent, with more immediate rewards, even for a newbie.

If the magazine continues as a free enterprise, then more power to their elbow, time is precious for everyone and they are giving up their own time for the benefit of others. If it does become more of a commercial enterprise though, I think they need to up their game a bit to ensure success.

Steve

Hi

This is Meltwater, one of the MagPi members, after spotting this thread, I thought I would pop my head over the parapet and see if we can get to the bottom of it (I just hope I don't regret doing so).

If we've over looked something (which is more than possible - there is not a vast amount of time available split between the team, while every effort is made where we can to check things) then I would like to ensure that suitable corrections are made.  The magazine is community based, and we accept that we can't get everything right on our own.

Firstly, the circuit is aimed to provide a direct link to the manual switches for the readers understanding, and also to aid with the basics of transistor selection.  While I am aware there is a question around the min gain value for the transistor used (RS quoted it as 210, but I've seen that as the typical value in other places, so RS may have this wrong and caused that problem).  Also, the calculation for the base resistor may incorrectly ignore the 0.7voltage drop, although I believe this results is less current drawn by the GPIO than expected.

I know there are people who do such electronics every-day, and probably can do stuff like this in their sleep, so I would welcome clear answers about this specific circuit.  I am well aware there are better options out there, but as mentioned, it was selected to allow a clear parallel between the circuits.

Right, I'm off to hide!

PS. The price of the printed edition is purely at cost price and to ensure we don't make loss on printing more than we sell.  The magazine will remain free online, just as it always has.  Printed versions were what people asked us to provide too, and we hope that allows more people to see it and hopefully become interested in the RPi and engineering (as per the foundations own goals).

Thanks meltwater.

Hi meltwater, I'd just like to say that minor mishtakes crop up in publications all the time - even after the most vigorous of applications of the blue pencil... At least with an online publication any issues can be caught within hours, rather than having perhaps a month's turnaround on corrections / clarifications.

That said I can appreciate the value of the option of hardcopy - squinting at a pdf is a soul destroying task for an old giffer like me and I find that the remoteness of said document distracts me from it's actual content.

Anyway, keep up the good work, I think that the mag addresses topics that would be of interest to the average Pi owner very well. My only tiny quibble with the publication is that I'm not a huge fan of the handwritten font, but that's just my personal taste. Good luck with the hardcopy launch!