A Beginner's Project With Possibilities

There's an amazingly cheap project available from multiple Chinese sellers that offers a good starting point for someone who has never built an electronics gismo before.  It's a tester that's good for go/nogo and frequency identification of crystals up to around 50Mh/z.  In theory it should check ceramic resonators and filters too, and maybe it has other uses, like a frequency meter or maybe - with a lille insight - can be used to indirectly measure inductance and capacitance.

I bought mine here for only £2.11 (British Pounds) and that included the shipping from China!  They vendor wants a massive £0.25 shipping now though! I've been looking at the little bag of parts for a couple of weeks now, so it's time to get the soldering iron out...

Here's a series of notes on the NextThingCo C.H.I.P. computer module.  At the moment they are in no particular order.  The notes all refer to the original CHIP and not the CHIP-Pro embedded module.  Due to the nature of the product this is all very command line orientated and we (mostly) eschew Graphics User Interfaces (windowing).

Bluetooth

Yes, the CHIP has Bluetooth capability but you need to work at it a little.  The key here is the bluetoothctl utility.  Mileage may vary but getting bluetooth peripherals to pair/connect and finally function boils down to:

bluetoothctl scan

I found that it was necessary to turn on the agent in order to get my bluetooth keyboards to function.  Pairing and a successful connection simply isn't enough.

agent on
connect 00:11:22:33:44

Note that command completion (using TAB) works at the bluetoothctl prompt, which is a huge relief when using the toy keyboard on a PocketCHIP!  This also works for the bluetooth device number: once seen it's only necessary to type the first couple of unique characters before hitting the TAB.

Stuck in GUI Mode?

So you did the...

sudo apt-get install xfce4

 ... and are now stuck in the (fairly useless for embedded applications) xfce4 environment?  You're seriously contemplating a reflash!  Use systemctl to change the default boot with a symlink: 

systemctl set-default multi-user.target

To change back to booting to the GUI:

systemctl set-default graphical.target

Note that this will kick you into raw full screen console mode, with the various consoles accessible by the usual Alt+F1 to F? key sequences.  As it's proper text mode for the display (not a windowing environment) the text will be bolder and look less enhanced, but IMHO it's more readable.

Battery Connector

The tiny white battery connector on the C.H.I.P. is a  JST-2.0 PH.  You can buy them here already terminated, rather cheaply, and without any postage charges.  Make sure you chose the 2 pin size.  If you are a member of our forums here, and have at least ten meaningful posts to your credit, I will post you two free ones if you simply PM me with your mail address.

Footnote on 28th May 2020

This slightly dated article isn't static, and will be added to in small ways from now on.  That's because I've secured a supply of C.H.I.P. modules directly from Chinese manufacturer - part of the run that Next Thing Co didn't pay them for.  I can't sell them at $9 (but Next Thing Co couldn't either as this broke them!) as I paid an arm and a leg for air freight; a local agent fee; plus European import duty, but they are still excellent value.  If you are interested in one or two them please Personal Message me through this portal as I don't sort my spam-filled mailbox that often.  I only have the modules themselves as I declined the offer of PocketChips and related modules.  I don't have the plastic "safety" covers even though the Chinese source promised them, but these were always a non-essential option anyway.

For the first twenty posters of a project built on Stripboard only:  post details and photos of your project built on Stripboard in these forums and I will send you a small pack of Stripboards from my present collection at my sole expense.

The simple conditions are:

• The project must be non-trivial - (no LED plus a resistor!).
• The project must function in some meaningful way.
• At least 50% of the wiring must be on an actual piece of standard Stripboard.
• Your description must run to at least 100 words accompanied by at least two reasonable pictures.
• You must PM me through this board with the postal address to send your reward to. (I won't exchange e-mails).
• My decision on if your project qualifies for a reward is final.
• The ongoing shipping risk is yours once I deliver your reward to my local post office.  (no second postings).
• I will use the cheapest uninsured postal method, so you may have to be patient.
• Only the first twenty such projects qualify though I might show a little flexibility if there are edge cases here.
• You should show a little willingness to answer other people's questions about your project.

Other benefits of joining in here as a member:

• Private hobbyists can advertise their surplus components and other electronic junk for free.
• You'll never be bothered with any on-site advertising or spam emails.  (I couldn't give a xxxx if there's zero revenue!).
• You'll never be asked for sponsorship: my hobby is my hobby.
• Start (and fully moderate) your own forum, just so long as it's of general interest to electronic hobbyists. (PM me on this).

My aim is to get this free and non-commercial forum off the ground, so barriers to freebies will increase as time goes on.  I've set about 100 GBP of my own money aside for this little promotion, so hopefully everyone will benefit in some way.  I will publicly acknowledge your contribution and advise the date your reward was posted right here on the forums.  Quite obviously your personal details won't be published or recorded anywhere on the site.  There is no commercial motivation whatsoever behind this offer: this site is purely a recreational hobby!  Get constructing!

A couple of Xmas's back my dear daughter bought me a full licence for Vcad as a present.  I used it to redesign a seven segment display stripboard, and then to layout a larger board simply as a trial.  The process was reasonably successful and I verified that Vcad wasn't money wasted.  The main problem here was the paucity of available component outlines - much of the work in designing a stripboard with Vcad was to flesh out the very bare symbols library.

Recently I revisited Vcad on the Windows laptop and decided to port my purchase to "the big screen"; namely the recently built AMD Ryzen 5 based under-desk that delivers more computer power than I've ever dreamed of.  The problem was that in the interim I'd finally carried out the switch away from Windows that I'd been promising myself for decades.  I was resigned to keeping a low cost Lenovo laptop pretty much only to run Vcad.  In the last few days I've been adding more drives in the Ryzen 5's capacious box and it struck me that I should explore using it for stripboard design.  I'd had a fair bit of experience with virtualisation on Windows machines, but didn't fancy a Windows virtual machine on a Linux box even though there was now oodles of RAM and twelve fast CPU cores available. 

Never having bothered with Wine I decided to see if it was still being actively developed and was pleasantly surprised when I arrived at the Wine website.  The install instructions were clear to follow and I had it running on Ubuntu 20.04 in no time.  I created a Windows sub-directory in my home directory and a child directory for notepad++.  The performance of notepad++ was an eye-opener, so how about Vcad?  Had there been an upgrade, or had that Aussie guy simply lost interest, like most stripboard design software authors have over the years?  Once again things were much more promising than I'd imagined possible, though it took a short while to locate Mr Lascelles site - it had moved, and so had the name of his package!

Yes, Vcad is now called VeeCAD, but the main takeaway here is that the nice Mr Lascelles has opened up the source code and isn't now charging for the full version.  You can download it (and the manual) for free from his download links.  This guy is obviously a stayer in the game, so many have fallen by the wayside over the years.  By opening up the internals of VeeCAD there's scope for others to make incremental improvements.

Like notepad++ the installation process on Ubuntu 20.04 under Wine was quick and flawless, but I will cover this in another article very soon.  I anticipate that VeeCAD will feature heavily on this site before too long, though I hope the odd few stripboard design software packages still standing will tell us all about their products too.  Please feel free to post your experiences with this (and other stripboard design software) in our forums, and share you hints and tips.

VeeCAD is FREE stripboard design software that nominally runs under Windows, but many in engineering and hobbyist community no longer use Windows.  If you aren't tied into the Windows ecosystem commercially - some would talk about M$ tentacles here - there are better and free alternatives amongst the ever expanding distributions of Linux.  So how to leverage all this free software into doing something really productive with stripboard?  For the home user the Ubuntu distribution of Linux, which is in turn based on the Debian distribution (that's how open source software works folks!), is the first port of call.  For that reason we are talking about Ubuntu and in particular the latest 64bit version 20.04 here.

Assuming you already have a recent copy of Ubuntu installed proceed as follows:

Go to the Wine downloads page and follow their amazingly clear instructions.  Click on your operating system, then on the page for that operating system select the most recent stable version - we don't do bleeding edge here!  Follow the amazingly clear instructions and then type wine at a terminal window prompt.  If all went well you'll get the Usage: wine... help messages and the system will then exit back to the prompt.  The Wine install worked for me with Ubuntu 20 without any of the usual snags about dependencies and version incompatibilities.  They've quite obviously spent a very long while honing this.

Now download VeeCAD from the download page - you'll likely want to download the manual as well.  If you download it using the archive manager then there's a direct way of extracting it.  If you don't already have a Windows sub-directory in your home directory then create one.  If you are well organised you'll create another sub-directory for VeeCAD and place the Setup file there.  Now name the .exe as an argument to Wine.

The rest is super easy, but as VeeCAD is 32 bit Windows you really should install it to Program Files (x86).

.

..

Make sure you've checked the place a desktop icon box before you hit [Install].  When install completes then just hit the run now button and presto!

Wine stores its Windows file system in a hidden directory called .wine in your home directory, but you don't have to make these files visible to your favourite Linux file manager to manipulate them.  Simply type winefile (not winfile) at a terminal prompt and it will throw up its own Windows file-friendly file manager.  Hitting the C:\ button at the top will open a child window onto the Wine file system where you've installed to.  You can navigate to the VeeCAD.exe file and click on it to start VeeCAD.   You can also use winefile to navigate to users -> <your_name> -> Start Menu and click on VeeCAD.lnk to start VeeCAD.   It's probably a good idea to put a shortcut to winefile on your Ubuntu toolbar.  But shouldn't there be an easier way to start a program?  Well, of course there is: when you told Wine to place a Windows desktop icon it went to Linux and did the same thing, but adding in the tricks to start Wine running on the correct .exe file first.  Apart from the visual appearance of its window your installed Windows program acts very much like any Linux one.  You can right click on the new Linux VeeCAD icon and add it to favourites so that it shows up on your toolbar - nothing could be easier!

If you ever feel a need to uninstall a Windows program then simply type wine uninstaller in a Linux terminal window and an (almost) genuine Windows installer dialogue will pop up.

A Footnote

I subsequently found out that you are supposed to run winecfg to set up the Wine environment for VeeCAD.  I found this out from the Help in a running copy of VeeCAD - doh!  There wasn't anything to change as the defaults were already as described, but you might want to insert a VeeCAD.exe entry in the winecfg Applications dialogue for completeness - see the Help screens after you run VeeCAD for the first time.  Maybe RTFM applies here!

____

A few weeks back I was tempted by a Pi - not the one with all the little seeds you understand.  No, that one isn't open source engineering, and quite frankly isn't for us professional (retired) engineers. Yes, you've guessed it: Orange Pi!  The sub-twenty-UK-pounds of the Orange Pi PC proved just too much to resist.  A board with a quad core CPU, 1GB of RAM, WiFi & Ethernet, HDMI video, IR receiver, Camera Port, 3xUSB, etc. at this price level is probably too good to be true.  Or is it?

I decided that boards which depend on a microSD for program storage are an economy too far.  Whilst this bottleneck might be OK in an ultra low cost embedded application development work requires something better.  So it was pay the few pounds extra for the eMMC version and see what turned up.  As it turned out there wasn't the expected six weeks or more wait for Chinese components, as despite all the world turmoil Orange Pi central had their pretty box on my desk in inside a month.

I don't generally rush off and try new gismos the same hour/day, but eyeballing the OP PC+ triggered childhood Christmas Morning Syndrome, and I just had to fire it up right away.  I'd omitted to order a power lead but the one 1.7/4.0mm for the Cubieboard 2 did the job fine.  Ditto HDMI converter, keyboard etc. for same.

Power up time: oh no not Android 4.4 again, and all in CHINESE!  This was not a good start!  Drawing on all my painful experiences with cheap Chinese Android tablets that had - often mysteriously - factory reset, I navigated through the hieroglyphics and attained English language nirvana!

Click on the massive Google Play icon... zilch!  Click on every one of the other giant icons... double zilch!  It had a dumb deaf and blind Android core installed so I'd need to sideload some apps.  But wait; enough of this nonsense; let's boot to a decent Linux distro from the microSD.  I'd never tried Armbian before but this seemed like a good time to start.

The first attempt at booting Armbian from the microSD didn't go well: I'd naturally chosen the latest version (Focal) but missed a warning that Focal images had been broken.  Stepping back to Buster solved this problem, and that booted after a short delay - we were getting somewhere!  Set the passwords; do the usual updates...

The next step was to transfer Armbian from the microSD to the on-board eMMC so that we could lose the slow card entirely.  This proved remarkably easy as there's a pre-written script called nand-sata-install to do exactly this.  Now we are flying as a boot is so much faster - yes, eMMC was certainly the right way to go here!  You can see the eMMC at the bottom centre (just above the dual row pin header) of the board in the first picture.  On the Plus version they've moved the second DRAM to the other side of the board (directly below the visible one near the centre of the board) to make room for it.  BTW if you do have the non-Plus version then don't make the mistake of going for a superfast A2 microSD card as there aren't any drivers for these in Armbian (yet) and it will likely run significantly slower than a much cheaper A1 specification card.

After my usual desktop tweaks I pulled the D language compiler from the repos: although I like Python, D takes a much better approach to higher level programming and also integrates almost seamlessly with C code for the low level bit twiddling.

sudo apt install gdc

How are we doing from a thermal stress point of view?  Well... so far the H3 isn't under much stress, but it can get a lot hotter!

Getting To The Pins

Next step was to get at the peripherals, and it turns out that WiringPi has already done the spadework for the H3 here - no sense reinventing the wheel!  There's a WiringPi port for the Orange Pi PC to be found here.

The H3 sports the following multi-functional input/out pins:

Port A (PA): 22 input/output port
Port C (PC): 19 input/output port
Port D (PD): 18 input/output port
Port E (PE): 16 input/output port
Port F (PF):  7 input/output port
Port G (PG): 14 input/output port
Port L (PL): 12 input/output port

The Orange Pi Plus PC can't possible provide user access to all these 108 pins within the limited board area, though unused peripherals can generally be reassigned to simple I/O:

With WiringPi installed we can now get at the pins at both BASH script and compiled C code level, the package also contains a wealth of examples.  I chose to test things out with a tiny script.  Just to throw some execution randomness and impose a parallel load on the H3 CPU I ran a HD movie in another window.  I can thus report that Kill Bill didn't kill the execution script!

PIN=1
while true; do
	gpio write $PIN 1
	sleep 0.05
	gpio write $PIN 0
	sleep 0.05
done

A fairly regular squarewave as expected, so the video playback isn't impacting the hardware timing, however the observant reader may note that the output frequency of the square wave on logical Pin 1 (physical Pin 12 - the red picohook) isn't the 10Hz it should be.  This is a - long by about 25% - error in the Armbian sleep routine and nothing directly to do with the hardware.  It would be interesting to trace the sleep routine implementation back to see exactly where/how this crept in.  Maybe more on this later.

The Conclusion...

So.. now we have a near perfect development platform for embedded applications.  The beauty here is that there are much smaller and even lower cost boards using the same basic hardware configuration but without unnecessary appendages like the HDMI interface to form the basis of really smart hardware.  Orange Pi Central has recognised this potential by promising Long Term Support for these boards - hardware projects generally have a far longer useful lifetime than software.  Fabricators should therefore be able to depend on continuity of supply!  If all this potential is fulfilled then Oranges really could become my favourite fruit!

Coming Up

I've ordered a few of the Orange Pi PC Plus' smaller even cheaper cousins - the Orange Pi Zero, to embedd in future Stripboard projects, so stay tuned for a first evaluation.

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