It’s certainly not just a fancy name for an electric motor, but the term “digital” was added by Dyson (I believe) to make his vacuum cleaners sound more exciting. Before that they were known as “brush-less” DC motors.
In simplistic terms, an electric motor works by having a moving electromagnet attracted to a fixed magnet, with the electromagnet on the spinning bit in the middle. Turn on the current and the electromagnet gets pulled towards the fixed magnet. Yeah! We have motion. However, when the two magnets reach each other they’re going to “stick”, so at that point you need to reverse the polarity of the current in the electromagnet so it changes from North to South, and it will then push itself away from the fixed magnet – carry on spinning.
In a traditional motor this is achieved using a commutator, which contains two contacts (+ve and -ve) called “brushes” which wipe against contacts on the spinning bit and provide power to the electromagnet. As the motor turns 180 degrees, the contacts are arranged so that the polarity is reversed – pull becomes push and vice versa, and the motor continues to rotate another 180 degrees – where it repeats.
To run smoothly you need more than two magnets, so something is always pulling, but that’s the general idea.
These brushes are a PITA. They cause friction, wear away, and make sparks. But it’s 19th Century technology and the best we had for a long time.
A brush-less DC motor uses electronics to switch the polarity in the electromagnet. It uses a sensor on the spinning bit to work out which electromagnets need current and when. This can be done with analogue or digital electronics according to taste. Hence someone decided to call it “digital” after a while, because digital was “cool”. However, a digital motor has many advantages – not least of which is getting rid of the hated brushes and the need to replace them periodically. If you have smart electronics the motor can be more efficient by applying exactly the right current for requirements, to more electromagnets. It’s similar in a way to electronic fuel injection motor vehicles (if you’re old enough to remember carburettors) – there’s a chance to put in the right power at the right time, saving energy and improving performance.
An AC motor doesn’t have the commutator problem, because the AC current is changing polarity all the time anyway. You could look at a brush-less DC motor as a AC motor, with the DC converted to AC by electronics.
To be fair, the Broadcom Ethernet adapter chips aren’t the best supported by FreeBSD. They’re okay, but for FreeBSD Intel rules the roost at 1-Gig and Chelsio at 10-Gig plus.
Unfortunately you may have no choice, as Broadcom chips are built in to the motherboards on some HP servers; notably the Microservers.
The Microserver Gen 7 is a great little box. I love them. I’m not so keen on the Gen 8 or Gen 10, as they’ve dropped a lot of the features that make the Gen 7 so adaptable. So after much investigation, I decided to either forego WoL support, or bung in a cheap Realtek card simply to wake them up, but with only two PCIe slots, it was a pity to waste one on a better supported Ethernet NIC. That was a long time ago, and I’ve had one eye out for a fix for a while.
And then last year someone looked at it, and I found references to this in bug tracker. Unfortunately I don’t know who to credit with the fix, and it hasn’t made it to the kernel yet as it’s not 100%, but if you need it I’ve patched the 12.1 driver based on all the notes I could find.
There’s a question about the new driver’s correct operation on laptops. Why you’d be using WoL on a laptop eludes me; but for the Microservers it just works.
Download the patched driver ‘C’ file above (as edited by yours truly – no guarantees), and copy it to /usr/src/sys/dev/bge/if_bge.c, rebuild the kernel and away you go. As it was a bug with the state the chip was left on shutdown, you have to reboot the NEW kernel to shut down in the correct state for WoL to work. Don’t forget to enable WoL in the Microserver BIOS too.
Although this fixes the WoL issue, I know the Broadcom chips are capable of more than the driver – for example jumbo packets. If you want better network performance with a Microserver, add a dual-port Intel Ethernet card instead. Sorry, HP/Broadcom.
A few months ago I was asked for comment on the idea that an embattled Theresa May was about to approve Huawei for the UK’s 5G roll-out, and this was a major security risk. Politics, I assumed. No one who knew anything about the situation would worry, but politicians making mischief could use it to make a fuss.
Now it’s happened again; this time with Boris Johnson as
Prime Minister. And the same old myths and half-truths have appeared. So is Chinese
company Huawei risky? Yes! And so is everything else.
Huawei was founded by a brilliant entrepreneurial engineer, Ren Zhengfei in 1987, to make a better telephone exchange. It came from the back to become the market leader in 2012. It also made telephones, beating Apple by 2018. While the American tech companies of the 1980’s grew old and fat, Huawei kept up the momentum. Now, in 2020, it makes the best 5G mobile telephone equipment. If you want to build a 5G network, you go to Huawei.
Have the American tech companies taken this dynamic interloper lying down? No. But rather than reigniting their innovative zeal, they’re using marketing and politics. Fear, Uncertainty and Doubt.
“Huawei is a branch of the evil Chinese State and we should have nothing to do with it.”
Huawei says it isn’t, and there’s no evidence to the contrary. The Chinese State supports Chinese companies, but that’s hardly novel. And whether the Chinese State is evil is a subjective judgement. I’m not a fan of communist regimes, but this is beside the point if you’re making an argument about technology.
“Huawei is Chinese, and we don’t like the government or what it does”.
So we should boycott American companies because we don’t like Trump? We do business with all sorts of regimes more odious that the CPC, so this is a non-argument. You could make a separate argument that we should cease trade with any country that isn’t a liberal democracy, but this could be difficult as we’re buying gas from Russia and oil from the Middle East.
“Huawei works for the Chinese secret service and will use the software in its equipment to spy on, or sabotage us.”
First off, Ren Zhengfei has made it very clear that he doesn’t. However, there have been suspicions. In order to allay them, Huawei got together with the UK authorities and set up the HCSEC in Banbury. Huawei actually gives HCSEC the source code to its products, so GCHQ can see for itself; look for backdoors and vulnerabilities. And they’ve found nothing untoward to date. Well, they’ve found some embarrassingly bad code but that’s hardly uncommon.
Giving us access to source code is almost unprecedented. No other major tech companies would hand over their intellectual property to anyone; we certainly have no idea what’s inside Cisco routers or Apple iPhones. But we do know what’s inside Huawei kit.
“Because Huawei manufactures its stuff in China, the Chinese government could insert spying stuff in it.”
Seriously? Cisco, Apple, Dell, Lenovo and almost everyone else manufacturers its kit in China. If the Chinese government could/would knobble anything it’s not just Huawei. This is a really silly argument.
So should we believe what the American’s say about Huawei? The NSA says a lot, but has offered no evidence whatsoever. The US doesn’t use Huawei anyway, so has no experience of it. In the UK, we do – extensively – and we have our spooks tearing the stuff apart looking for anything dodgy. If we believe our intelligence services, we should believe them when they say Huawei is clean.
Being cynical, one might consider the possibility, however remote, that America is scared its technology companies are being bested by one Chinese competitor and will say and do anything to protect their domestic producers; even though they don’t have any for 5G. Or if you really like deep dark conspiracies, perhaps the NSA has a backdoor into American Cisco kit and wants to keep its advantage?
The US President’s animosity to trade with China is hardly a
secret. Parsimony suggests the rest is fluff.
End-to-end encryption means that Facebook doesn’t have access to the content of messages. Right now, ONLY Facebook can read your private message content, but that will change. (Actually, that’s not true – your employer can too, and that won’t change, but it’s beside the point)
Given Facebook’s entire business model is collecting and
selling personal data on its users, this might sound strange. You can bet it’s
nothing to do with making the world a safe place for political activists in
repressive countries. Such countries can simply block Facebook.
But there are three reasons they may wish to do this:
Right now law enforcement can ask Facebook for
data. If Facebook refuses, there can be a stink. If it hands it over, there can
be a stink. If Facebook can shrug its shoulders and say “can’t be done”, it’s
off the hook. Apple has done this.
If Facebook’s system is insecure, someone may
steal personal data from it in the future, leading to embarrassment and GDPR
complications. If it’s encrypted while at Facebook, this cannot happen.
Hard core criminals know all about how to use encryption.
Facebook is used for recruiting. If Facebook has to face the music for this,
with end-to-end encryption they have plausible deniability.
It’s worth noting that political activists have well established secure communication channels too. Paedophile networks have the knowledge to do this, and do. There are plenty of “dark web” options to keep things secret.
So far from protecting the public, the only reason Facebook has to do this is to protect itself.
When Google launched its smart speaker it was playing catch-up with Amazon. The Echo had an established ecosystem, and unless Amazon blew it, this lead looked unassailable. The field was Amazon’s to lose.
Since then, Amazon’s arrogance seems to have taken it towards such a losing strategy. Glitzy launches of new gadgets are not enough to maintain a lead. I have a sample of pretty much every Echo device ever sold, and the newer ones aren’t that much better than the old ones. The build quality was always good, and they work.
What could damage the Echo is the slide in functionality.
Most people assumed that the rough edges – things you should be able to do but couldn’t – would be addressed in time. Google stole a march by recognising the person speaking, but Amazon has caught up. Sort-of. Meanwhile Google has been catching up with Amazon on other functionality and ecosystem.
What Amazon is failing to realise is that they’re selling smart speakers. This is the core functionality. They came up with the technology to link speakers in groups, so you could ask for something to be played “Upstairs”.
This is still there, but it’s been made almost useless. In the beginning you could play anything you wanted on an Echo. All music purchased direct from Amazon was added to your on-line library. There was also Amazon’s Prime music service. The latter has gone down hill recently, with the good stuff moved to a separate “full” streamin service. The ability to play your own music by uploading your MP3 files to your library. This facility has just “gone”, as of the start of the year.
Loyal Amazon customer assumed that it would go the other way, and that you’d be able to stream from your local source to your smart speaker groups. Amazon has blocked this, although some third party skills can play media to a single Amazon speaker. Not so smart.
Now Echo users are about to be hit again. From next month feed of BBC Radio, and other things, is changing. You’ll still be able to get them, but only on a BBC skill. The effect of this is that you can’t use an Echo as a radio alarm clock and more, the alarms will be confined to built in sounds. No longer will I be able to wake up to Radio 4’s Today program at 6am. Unfortunately I will still have to wake up at that time.
Ironically, one of Amazon’s enhancements is an Echo Dot with a time display. Just in time for it to be made useless by the software.
Looking at the change, I also strongly suspect you won’t be able to play a radio station on a group of speakers either. The speaker group technology is limited to Amazon’s own streaming service.
The Echo/Alexa system used to just work. Unless Amazon reverses these catastrophic decisions, it just doesn’t work. And now the public has a taste for this functionally, someone else can walk in and provide it.
The interpreted language Python is a lot of fun. It’s great
for quick and dirty lash-ups, and has list comprehensions whilst being easier
to use that Haskell. There are many great reasons why you would never deploy it
in a production environment, but that’s not what this article is about.
In the UK, the government decided that schoolchildren needed
to learn to code; and Python was picked as the language of choice.
Superficially it looks okay; a block structured BASIC and
relatively easy to learn. However, the closer I look, the worse it gets. We
would be far better off with Dartmouth BASIC.
To fundamentally understand programming, you need to fundamental
understand how computers work. The von Neumann architecture at the very least.
Sure, you can teach CPU operation separately, but if it’s detached from your
understanding of software it won’t make much sense.
I could argue that students should learn machine code (or
assembler), but these days it’s only necessary to understand the principle, and
a high level language like BASIC isn’t that dissimilar.
If you’re unfamiliar with BASIC, programs are made up of
numbered lines, executed in order unless a GOTO is encountered. It also incorporates
GOSUB/RETURN (equivalent to JSR/RTS), numeric and string variables, arrays, I/O
and very little else. Just the basic building blocks (no pun intended).
Because of this it’s very quick to learn – about a dozen
keywords, and familiar infix expression evaluation, and straightforward IF..THEN
comparisons. There are also a few mathematical and functions, but everything
else must be implemented by hand.
And these limitations are important. How is a student going
to learn how to sort an array if a language has a built-in list processing
library that does it all for you?
But that’s the case for using BASIC. Python appears at first
glance to be a modernised BASIC, although its block structured instead of
having numbered lines. That’s a disadvantage for understanding how a program is
stored in sequential memory locations, but then structured languages are easier
But from there on, it gets worse.
Data types are fundamental to computing. Everything is digitised
and represented as an appropriate series of bits. You really need to understand
this. However, for simplicity, everything in python is treated as an object,
and as a result the underlying representation is completely hidden. Even the
concept of a type is lost, variables are self-declaring and morph to whatever
type is needed to store what’s assigned to them.
Okay, you can do some cool stuff with objects. But you won’t
learn about data representation if that’s all you’ve got, and this is about
teaching, right? And worse, when you move on to a language for grown-ups, you’ll
be in for a culture shock.
A teaching language must have data types, preferably hard.
The next fundamental concept is data arrays; adding an index
to a base to select an element. Python doesn’t have arrays. It does have some
great built in container classes (aka Collections): Lists, Tuples, Sets and
Dictionaries. They’re very flexible, with a rich syntax, and can be used to
solve most problems. Python even implements list comprehensions. But there’s no
Having no arrays means you have to learn about the specific
characteristics of all the collections, rather than simple indexing. It also
means you won’t really learn simple indexing. Are we learning Python, or
fundamental programming principles?
Unlike BASIC, Python is block structured. Highly structured.
This isn’t a bad thing; structuring makes programs a lot easier to read even if
it’s less representative of the underlying architecture. That said, I’ve found
that teaching an unstructured language is the best way to get students to
appreciate structuring when it’s added later.
Unfortunately, Python’s structuring syntax is horrible. It
dispenses with BEGIN and END, relying on the level of indent. Python aficionados
will tell you this forces programmers to indent blocks. As a teacher, I can
force pupils to indent blocks many other ways. The down-side is that a space
becomes significant, which ridiculous when you can’t see whether it’s there or
not. If you insert a blank line for readability, you’d better make sure it
actually contains the right number of spaces to keep it in the right block.
WHILE loops are support, as are FOR iteration, with BREAK
and CONTINUE. But that’s about it. There’s no DO…WHILE, SWITCH or GOTO.
You can always work around these omissions:
do <something> until <condition>
while True: <something> if <condition>: break
You can also fake up a switch statement using IF…ELSEIF…ELSEIF…ELSE.
Really? Apart from this being ugly and hard to read, students are going to find
a full range of control statements in any other structured language they move
In case you’re still simmering about citing GOTO; yes it is
important. That’s what CPUs do. Occasionally you’ll need it, or at least see
it. And therefore a teaching language must support it if you’re going to teach
And finally, we come on to the big one: Object Orientation.
Students will need to learn about this, eventually. And Python supports it, so
you can follow on without changing language, right? Wrong!
Initially I assumed Python supported classes similar to C++,
but obviously didn’t go the whole way. Having very little need to teach
advanced Python, I only recently discovered what a mistake this was. Yes, there
is a Python “class”, with inheritance. Multiple inheritance, in fact. Unfortunately
Python’s idea of a class is very superficial.
The first complete confusion you’ll encounter involves class
attributes. As variables are auto-creating, there is no way of listing
attributes at the start of the class. You can in the constructor, but it’s
messy. If you do declare any variables outside a method it silently turns them
into global variables in the class’s namespace. If you want a data structure,
using a class without methods can be done, but is messy.
Secondly, it turns out that every member of a class is
public. Always. You can’t teach the very important concepts of data hiding; how
to can change the way a class works but keep the interface the same by using accessors.
And talking of interfaces, what about pure virtual
functions? Nope. Well there is a way of doing it using an external module.
Several, in fact. They’re messy, involving an abstract base class. And, in my
opinion, they’re pointless; which is leading to the root cause why Python is a
bad teaching language.
All Round Disaster
Object oriented languages really need to be compiled, or at
least parsed and checked. Python is interpreted, and in such a way as it can’t
possibly be compiled or sanity checked before running. Take a look at the
eval() function and you’ll see why.
Everything is resolved at run-time, and if there’s a problem
the program crashes out at that point. Run-time resolution is a lot of fun, but
it contradictions object orientation. Things like pure virtual functions need
to be checked at compile time, and generate an error if they’re not implemented
in a derived class. That’s their whole point.
Underneath, Python is using objects that are designed for
dynamic use and abuse. Anything goes. Self-modifying code. Anything. Order and discipline
are not required.
So we’re teaching the next generation to program using a
language with a wide and redundant syntax and grammar, incomplete in terms of
structure, inadequate in terms of object orientation, has opaque data representation
and typing; and is ultimately designed for anarchic development.
Unfortunately most Computer Science teachers are not
software engineers, and Python is relatively simple for them to get started
with. The problem is that they never graduate.
If you’re trying to get Talkmobile working with the current version of Android and have tried various settings on the Web with no luck. The Talkmobile web site itself is also incorrect. Here are the real ones as of right now…
Go to “Access Point Names” under setting somewhere. You’ll see Vodafone ones already there, probably. Ignore them.
Create a new one. Call it “Talkmobile” or whatever you fancy. The only three settings you need to change are:
APN Name: talkmobile.co.uk
User name: wap
APN Type: * (if this doesn’t work try “Default”)
I haven’t given the MMS settings because I leave them blank and avoid rip-off charges!
I reviewed their first digital model, the DM-5R, and concluded it was a bad idea as it only implemented Tier 1 and therefore could only talk to identical transceivers. A real pity. There is supposed to be a Tier-II version, the DM-5R Plus, but I don’t know anyone who’s seen one and even the specifications say it’s isn’t compatible with Motorola. Anyway, it seems to be history or myth now the DM-9HX has arrived.
The DM-9HX does Tier II, and should talk to DMR sets from other manufacturers and work through repeaters. I haven’t personally tested this properly as yet, but indications are good. So with that in mind, on with an initial review:
I’ll assume you know previous Baofeng models well enough and concentrate on the differences. But just in case you don’t, the legendary Baofeng UV-5R series are cheap and cheerful handheld dual-band FM 2m/70cm transceiver with a speaker/mic socket and an MSMA connector for whatever antenna you choose. There is a tri-band model, and they all seem to have a built-in torch. A number of variations in case style exist, including waterproof, as do versions with uprated RF. But they’re pretty much identical at the user level; and they’re the mainstay of many people’s community PMR set-ups as well as a no-brainer for Ham use.
Baofeng announced it was going to produce a digital version, which was physically interchangeable with previous models but with added DMR capability. This is a great proposition for people like me, with dozens of UV-5R batteries, antennas, chargers, cases and so-on. It protects your investment whilst allowing controlled migration to DMR. It’s been a long time coming, but now it’s here.
So first off – the interoperability is there. It uses exactly the same accessories as the UV-5R. It’s the same size and looks like a UV-5R – apart from the all-new display. Good job. The only physical difference is the programming cable, which is a direct USB feed into the microphone socket. And it doesn’t work with CHIRP. If you look closely, the label also says DM-9HX (check the picture near the top) and the keypad is overprinted for digital mode – alpha instead of menu shortcuts. The DM-5R/Plus had a black VFO button but they’ve gone back to orange with this model. I’ve had to put a rubber sleeve on it to find it amongst the others.
Inside the box you get a new “digital” antenna, the standard charger and the large battery. I’ve yet to test how much difference the fancy antenna makes; for ease of carrying, and like-for-like comparison, I swapped it for a standard battery and a stubby antenna. Moonraker supplied a standard Beofeng headset (yeah) with theirs; others don’t. The charger is the same, and it comes with the larger BL-5 12Wh battery although the smaller type still fit.
It also comes with an English manual, which is reminiscent of the one supplied with the DM-5R. It doesn’t actually relate to the DM-9HX, which is different enough for this to matter. But we’re radio amateurs, right? We like fiddling with things to find out how they work.
Compared to the analogue models, the user interface is much improved in terms of sanity, while remaining similar in some respects. The buttons do more-or-less the same, with the side ones being programmable. Alpha text entry on the keypad is now Nokia-like, with the # key switching case and three alpha characters on each number key.
The display is a high-res monochrome dot-matrix instead of a segmented LCD found on the analogue models and the DM-5R. It’s very clear to read, and back-lit either permanently or on a timer. There are also no more voice prompts. This is either a good or bad thing, depending on your taste.
Instead of settings being arranged in one long numbered list, in the new world they’re in a hierarchy of menus. Some settings are in odd places, but in general it’s a big improvement and easy to get around. The layout in the manual is simply incorrect, but even then it didn’t take too long to find most things. Some, however, were more difficult – read on and save yourself some trouble.
One handy feature of Beofeng analogue sets is the “dual watch”. This allows you to monitor two frequencies, and optionally lock on to the active one for transmissions. Although it appears in the manual, it wasn’t in the menu. The truck is to turn off “Power Saving” mode, after which it appears. There’s no sensible explanation of “Power save” mode, but it’s on by default.
Another oddity is tone squelch. CTCSS can be set on T, R and C. I’m not sure what ‘C’ is but I suspect it simply sets both T and R at once. The same menu identifies itself as setting DCS modes, but doesn’t appear to allow any such thing. I’ve yet to find a way of doing it on the radio, but you can from the programming software. This turns out to be true of quite a few things, for not apparently good reason.
Remember the analogue channel saving game, where you could write current settings to a memory and it sometimes worked? It was always a bit hit-and-miss in my experience, so I left it to CHIRP, but the DM-9HX has dropped the option entirely from the radio but it’s still described in the manual.
I struggled to program our local repeater in to the set, and discovered the following:
It’s not possible to save current VFO settings to a memory.
It is possible to edit a memory when in MR mode, to an extent.
This is logical, but is a PITA if you’ve just got something working in VFO mode. and you want to save it. If you do want to store to a channel, switch to MR mode, choose the channel and then edit. The editing menu options vary from VFO mode, just to make life interesting. For example, you can’t program an offset transmit frequency using the direction/offset menu settings (they’re disabled in MR, but not in VFO). However, you can enter separate Tx and Rx frequencies directly (calculating the Tx in your head, of course). It’s a bit illogical, but it works.
Another thing you’ll need to know is that a memory location is either designated as Digital or Analogue. This is set using the programming software, and cannot be changed on the radio. Neither can unused memory locations be brought in to use. As shipped, a mixture of sixteen analogue and digital channels were configured by default; you’re going to need the programming software if you want to make use of the memory, but saying that, making quick tweaks to an existing memory on the radio is much easier than it was before. As a suggestion, you might want to define a load of channels in software early on, so you have enough to choose from when programming using the radio.
One big worry with the first unit I tested (I have others waiting) is that the CTSS appeared not to work on receive. However, leaving it set on Tx it seemed to work for both. Further investigation needed on this one.
And so to the programming software:
I received the programming cable and a small anonymous CD containing many files. One of these was a ZIP with a name in English identifying it as related to the DM-9HX, so I installed it. It was the right one, but it’s hard to tell because it came up in Chinese, and does so every time. Keep going through the menus until you find “English”, select the option and all will be well – assuming you don’t speak Chinese.
The cable is a USB lead, with multi-ring plugs that go into the mic socket. I’d have liked to see a micro-USB socket on the radio for programming, but it works. Windoze recognises without the need for any special COM port driver. Yeah! It recognises it as a mouse, but it works.
After this rocky start, I’m pleased to report that the programming software has worked perfectly so far. Some of the terminology for settings doesn’t match the radio, manual or any known term I know of but you can figure it out easily enough.
There’s no manual for the software, but it does have useful help information that appears in a lower window pane. A lot of additional options related to digital operation, such as phone books and zones. As a GUI, it works as you might expect.
For locking down the radio, you can select which menus are available to the user in a way that seems very flexible. You can also set the allowed frequencies, as you could with the analogue sets.
There is, however, one serious limitation to the software. I have found no way of importing/exporting memories to a spreadsheet. You have to enter them all, one at a time, using dialogue boxes. This is NOT cool.
Will CHIRP support this? Well no one has been inclined to add support for the DM-5R since 2016, but then again who would want to use one? Unfortunately, looking at the technicalities and very different nature of DMR it’d take some work to add, although it’s been propo DMR-6X2sed for 0.5.0.
The programming for another Beofeng DMR, the DMR-6X2, does import/export CSV so it’s entirely possible I’ve just not figured it out yet but I’ve looked closely.
That’s about it for this quick look. I’ve done some RF tests, the results are to follow, as is some proper photography. I’ve spoken to friends over analogue. The sound quality was described as fine, but through a repeater to mobile stations.
To conclude, after the false-start on the DM-5R, the DM-9HX delivers – both in terms of DMR functionality, compatibility and as a major step forward in usability. With a few rough edges.