I’ve been on a weight loss diet lately. In more ways than one…

As an old fan of the Minimal Mac weblog (now extinct), I’ve always been intrigued by simplification. Fewer applications, a less cluttered desk (oops, not there yet!), simpler tools, and leaner workflows. And with every new laptop over the years, I’ve been toning down the use of tons of apps, widgets, RSS feeds, note taking systems, and reminders.

Life is about flow and zen, not about interruptions or being busy. Not for me, anyway.

One app for all my documents (DevonThink), one app for all my quick notes (nvAlt), one programming-editor convention (vim/spacemacs), one off-line backup system (Arq), one on-line backup (Time Machine), one app launcher / search tool (Spotlight) … and so on.

I’ve recently gone back to doing everything on a single (high-end Mac) laptop. No more tinkering with two machines, Dropbox, syncing, etc. Everything in one place, locally, with a nice monitor plugged in when at my desk. That’s 1920×1200 pixels when on the move, and 2560×1600 otherwise, all gorgeously retina-sharp. I find it amazing how much calmer life becomes when things remain the same every time you come back to it.

I don’t have a smartphone, which probably puts me in the freaky Luddite category. So be it. I now only keep a 4 mm thin credit-card sized junk phone in my pocket for emergency use.

We’ve gone from an iPad each to a shared one for my wife Liesbeth and me. It’s mostly used for internet access and stays in the living room, like newspapers did in the old days.

I’ve gone back to using an e-paper based reader for when I want to sit on the couch or go outside and read. It’s better than an iPad because it’s smaller, lighter, and it’s passively lit, which is dramatically better in daylight than an LCD screen. At night I read less, because in the end it’s much nicer to wake up early and go enjoy daylight again. What a concept, eh?

While reading, I regularly catch myself wanting to access internet. Oops, can’t do. Great!

As for night-time habits: it’s astonishing how much better I sleep when not looking at that standard blueish LCD screen in the evening. Sure, I do still burn the midnight oil banging away on the keyboard, but thanks to a utility called f.lux the screen white balance follows the natural reddening colour shift of the sun across the day. Perfect for a healthy sleep!

Our car sits unused for weeks on end sometimes, as we take the bike and train for almost everything nowadays. It’s too big a step to get rid of it – maybe in a few years from now. So there’s no shedding weight there yet, other than in terms of reducing our CO2 footprint.

And then there’s the classical weight loss stuff. For a few months now, I’ve been following the practice of intermittent fasting, combined with picking up my old habit of going out running again, 2..3 times per week. With these two combined, losing real weight has become ridiculously easy – I’ve shed 5 kg, with 4 more to go until the end of the year.

Eat less and move more – who would have thought that it actually works, eh?

But hey, let me throw in some geek notes as well. Today, I received the Withings Pulse Ox:

(showing the heart rate sensor on the back – the front has an OLED + touch display)

It does exactly what I want: tell the time, count my steps, and measure my running activity, all in a really small package which should last well over a week between charges. It sends its collected data over BLE to a mobile device (i.e. our iPad), with tons of statistics.

Time will tell, but I think this is precisely the one gadget I want to keep in my pocket at all times. And when on the move: keys, credit cards, and that tiny usually-off phone, of course.

Except for one sick detail: why does the Withings “Health Mate” app insist on sending out all my personal fitness tracking data to their website? It’s not a show-stopper, but I hate it. This means that Withings knows all about my activity, and whenever I sync: my location.

So here’s an idea for anyone looking for an interesting privacy-oriented challenge: set up a Raspberry as firewall + proxy which logs all the information leaking out of the house. It won’t address mobile use, but it ought to provide some interesting data for analysis over a period of a few months. What sort of info is being “shared” by all the apps and tools we’ve come to rely on? Although unfortunately, it won’t be of much use with SSL-based sessions.

This will be the last post in “summer mode”. Next week, I’ll start posting again with articles that will end up in the Jee Book, as before – i.e. trying to create a coherent story again.

The first step has just been completed: clearing up my workspace at JeeLabs. Two days ago, every flat surface in this area was covered with piles of “stuff”. Now it’s cleaned up:

On the menu for the rest of this year: new products, and lots of explorations / experiments in Physical Computing, I hope. I have an idea of where to go, but no definitive plans. There is a lot going on, and there’s a lot of duplication when you surf around on the web. But this weblog will always be about trying out new things, not just repeating what others are doing.

My focus will remain aimed at “Computing stuff tied to the physical world” as the JeeLabs byline says, in essentially two ways: 1) to improve our living environment in and around the house, and 2) to have fun and tinker with low-cost hardware and open source software.

For one, I’d like to replace the wireless sensor network I’ve been running here, or at least gradually evolve all of the nodes to new ARM-based designs. Not for the sake of change but to introduce new ideas and features, get even better battery lifetimes, and help me further in my quest to reduce energy consumption. I’d also like to replace my HouseMon 0.6 setup which has been running here for years now, but with virtually no change or evolution.

An idea I’d love to work on is to sprinkle lots of new room-node like sensors around the house, to find out where the heat is going – then correlate it to outside temperature and wind direction, for example. Is there some window we can replace, or some other measure we could take to reduce our (still substantial) gas consumption during the cold months? Perhaps the heat loss is caused by the cold rising from our garage, below the living room?

Another long-overdue topic, is to start controlling some appliances over wireless, not just collecting the data from what are essentially send-only nodes. Very different, since usually there is power nearby for these nodes, and they need good security against replay-attacks.

I’ll want to be able to see the basic “health” indicators of the house at a glance, perhaps shown inconspicuously on a screen on the wall somewhere (as well as on a mobile device).

As always, all my work at JeeLabs will be fully open source for anyone to inspect, adopt, re-use, extend, modify, whatever. You do what you like with it. If you learn from it and enjoy, that’d be wonderful. And if you share and give back your ideas, time, or code: better still!

Stay tuned. Lots of fun with bits, electrons, and molecules ahead :)

Parrots are birds that are kept by many people as pets. These birds are known to have impressed human beings for many centuries. Parrots were kept by many ancient people starting from kings, warlords, pirates and even the common people. The birds are admired because of their colorful feathers, their high levels of intelligence and their talking ability. There are very many types of parrots and different types have their own style and personality that is very peculiar from the rest. Different types of parrots love to eat certain types of food and they love to live in a different unique manner compared to other types. If you own a parrot you should take care of the bird wisely and maintain it very well to make it have an enjoyable life in your household. Some of the breeds of parrots include; The Colorful Macaw, The Comedic Cockatoo and The Majestic African Grey. You can make your parrot very happy, playful and healthy by purchasing the most perfect parrot cage for your parrot. Different types of parrots love to live in certain specific types of cages. The cage of your parrot should have a good space that will give the bird enough room to play and exercise-since parrots are birds that are playful and they love to have regular exercise. The cage should give room for your parrot to be able to stretch its wings; the cage should have enough space that will give the parrot enough room when feeding. The cage should also give the pilot enough space to play with its toys and also preen its feathers. Most of the parrot cages are manufactured with “play-top” that enables the parrot to play and others have an additional pullout tray beneath the parrot cage that enables you to collect the litter easily.

Some pet shops sell parrot cages that you will be required to assemble before putting your parrot in the cage. You will be supplied with a manual of how to assemble the cage. You will be required to assemble the “bottom stand” first and finish by putting the perches and the feeders into their position. For you to have a healthy parrot you will always be required to clean the parrot cage very well. You will be required to replace the cage liners daily, you will also be required to wipe away all the food-leftovers and the waste daily and you will also be required to wash the food and water dishes daily. You will also be required to thoroughly clean the perches and the toys at least once per week. A thorough cleaning should for the entire parrot cage should be done at least once in every month. Sometimes you will be required to dismantle the whole cage and wash every part very well then you will re-assemble the cage again.

Different types of parrot cages can be purchased in many stores and pet shops. You can also purchase the parrot cages from the online pet supermarkets.

You should take care of your parrot and maintain it very well for the bird to be always happy and attractive, you should feed it well, spray it, clean it and you will be assured of a very good pet.

It’s time to get some new hardware out the door, which I’ve been doodling with here at JeeLabs for quite some time, and which some of you might like to tinker with as well.

The first new board is the Tinker Pico, which was already pre-announced a while ago. Here’s the final PCB, which is being sent off to production now, soon to appear in the shop:

As before, each week consists of one announcement like this, and one or more articles with further details, ready for release on successive days of the week – three in this case:

• Tinker Pico v1– Wed
• How to upload over FTDI– Thu
• Writing code for the Tinker Pico– Fri

This is merely a first step, running pretty basic demo code. Stay tuned for more options…

(For comments, visit the forum area)

The typical end-user of your IoT products wants them up and running fast with minimum hassle once they bring them home. They don’t want to be presented with initial configuration mechanisms/options they don’t understand, and their enthusiasm quickly diminishes if you make them struggle to get the product going.

A colleague once said “If you can’t explain how it works to your grandma in five minutes, you don’t understand it well enough”, I’d re-phrase that to “If the end user can’t get your product all configured and running in five minutes, you haven’t done good enough work on designing it”. That, of course, raises the bar for the developer. Ease of use comes at the cost of increased analysis/development/testing time, but all that pays off with improvement in customer experience.

When designing IoT hardware you are often balancing product cost vs ease of use. One of the old-school approaches to hardware configuration was to have DIP switches on your PCB, which of course only allows for limited configuration options (not to speak about the complexity for the end-user). Basic LCD graphical UIs with keys ease up this task, but add to the product cost. Configuration over serial connection or re-flashing the product with correct parameters is out of question for a product that claims to be user-friendly.

With the appearance of cheap, Wi-Fi enabled SoCs like the ESP8266 things rapidly changed. It is now possible to send Wi-Fi connection credentials to a non-connected ESP8266 through Espressif’s version of TI’s Smart Config, or use Wi-Fi Protected Setup (WPS) to configure your product’s connection with the simple push of a button. Alternatively one can simply have the ESP8266 start up a Wi-Fi access point with DNS captive portal configuration UI. This means you have a configured, Internet connected product within a minute of plugging it in.

Using a dedicated cloud M2M server you can even eliminate the need to configure the local firewall, avoid software environment setups, and have full control of the connected device in no time. Naturally security is essential and running things over TLS channel is a must. Firmware over the air updates capability ensure the hardware runs latest bug-free code and gives you peace of mind.

I’m working on a line of next generation connected projects that utilize these (and many more) techniques and putting the the accumulated experience to work.

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What will it take to support the LPC824 µC, i.e. the Tinker Pico, from the Arduino IDE?

As the Arduino IDE has been evolving and growing over the years, more and more µC platforms have been added – both officially and unofficially – after the initial ATmega µC’s. One of the earlier ones was Energia, which was created as a fork to support TI’s MSP430 chips, but as the IDE matured, it has become easier to support several other architectures in the mainstream build as a simple add-on, such as ESP8266 and STM32.

Sooo… let’s try and find out how hard it would be to include our LPC824 µC into the mix:

• Adding a new Arduino platform– Wed
• Extending the “ide-hardware” project– Thu
• A quick hack to make it compile– Fri
• Uploading via the IDE– Sat

So far, this is merely an exploration, as I said. A complete port will take considerably more effort. I’m also considering moving a bit beyond the digitalRead/Write conventions…

(For comments, visit the forum area)

Now that we have connected our project to the local network, we are immediately faced with another challenge: how can we reach it? Using WPS/SmartConfig means we force the unit into DHCP settings mode, IP address is auto assigned by the router in that case. You may not have access to the router’s settings to force static IP leases. Finding your connected project’s IP address isn’t exactly trivial and certainly not something we expect from the end-users to be capable of doing themselves. What we need is to simply type the product hostname and it should show up, something like typing “fridge.local” or “garage-door.local” to your phone’s browser should bring you to the device control UI.

It seems that there is no solution that “just works”, it pretty much depends on the setup that you have. iOS supports mDNS/DNS-Sd/ZeroConf out of the box, Windows uses NetBIOS and more recently (from Vista onwards) LLMNR and with Linux  you have to take care to install the respective protocol yourself. I’m not sure about local hostname resolution on Android, I wasn’t able to get it running on my Android devices. Setting DHCP hostname option doesn’t seem to be universal solution either and only works in some cases, if the router supports it.

I’ve included mDNS, NetBIOS and DHCP hostname support in my latest ESP8266 projects, but am still looking for universal solution.

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Let’s get that upload going. Remember, this is about adding a “hardware platform” to the Arduino IDE so it can compile and upload files to a Tinker Pico, based on the LPC824 µC.

There are two parts to this: 1) getting all the IDE setup files right so that it knows how to compile & upload, and 2) implementing pinMode(), digitalWrite(), etc. so they can be used with LPC824 microcontrollers in the same way as with ATmega’s and other µC’s.

So let’s tackle these issues one by one, shall we?

• Compile and upload the bare minimum– Wed
• Using an LPC824 the Arduino way– Thu

Here’s my very first compile and upload to a Tinker Pico:

(For comments, visit the forum area)

I last blogged about this in December 2013 when the second version of my ATmega328 & DS18B20 based temperature sensor, installed on 29 December 2011, had just reached the 2 year mark on the original set of batteries. That’s pretty good going and I’d have been happy with that but how long would it last until those Energizer batteries needed replacing? Well I found out in March of this year when it finally started to report erroneous readings, yes that is over 3 years on one set of AA batteries. To be honest, I did have a false alarm a few weeks prior when it started to transmit very irregularly but it recovered from that, presumably due to the increase in temperature affecting the battery capacity.

Like I said in the last post on this, this particular sensor was positioned where it didn’t have the best signal so it often had to retransmit and being the oldest running one it had started off with some pretty poorly optimised code and was off to a bad start to begin with. Needless to say I am more than happy with this result and I only wish I had logged the battery voltage over time of some of my other sensors but as it is they only report the current level so that Node-RED can alert me if one gets low.

@RossDargan Finally replaced them last month. pic.twitter.com/DYE0wfyON5

— Nathan Chantrell (@nathanchantrell) April 7, 2015

This was a quick project to add notifications for when I get real physical mail. This is something I’ve had on my mind since I made my first SMS doorbell notification system back in 2004 and I finally got around to it last month.

First of all I picked up a cheap internal letterbox flap and fixed that over the internal side of the letterbox opening. Then I took a microswitch that I had salvaged out of an old dot matrix printer some time ago and made a little right angle bracket from some perforated metal strip I had lying around. A few little adjustments to the microswitch actuation lever and I had it operating the switch as soon as the flap was moved even only slightly. It also operates it as it closes but that is easily taken care of in code to prevent duplicate notifcations and can also be used to detect if something is stuck part way through the letterbox instead of being pushed all the way through.

I connected the switch to a TinyTX3 running the same code as I use for reed switches and my doorbell which uses a pin change interrupt to sends a notification via the RFM12B wireless network which is then picked up by the Tiny328 connected to my server. From there Node-RED alerts me via speech and my LED matrix display if I am in or if I am out it sends me a notification via Whatsapp.

For now this is connected to its own dedicated TinyTX but I’ve somehow ended up with no less than 4 TinyTX nodes in close proximity around the door (doorbell, letterbox, outside temperature and hall temperature/air pressure) so I am working on a new node to combine these into one unit as well as adding some more features for controlling LED porch lights and so on. At the moment it is looking like this will be an ESP8266 node so watch this space.

I had long used the unofficial Google speech API for voice notifications (TTS) as it has a very good, clear voice, much better than Festival which I had used previously. However late one night a couple of months ago this stopped working as Google started to redirect it to a captcha if you tried access it directly. That’s fair enough I suppose, it’s their service to do with what they like and it was never even advertised as a publicly available API for this purpose so all of us who were using it were on a free ride. I’m sure there will be ways around this but it got me looking at alternatives again.

This lead me to Ivona which is a speech synthesis system originally developed by a Polish company but is now owned by Amazon. Using their beta Speech Cloud service you can get a free account for “development purposes” which allows you to make 50,000 requests per month. I don’t know about you but that is more than enough for me.

My speech notifications originate from several sources but primarily they come from Node-RED which runs on my Debian server and this does not have an audio output connected into my whole house audio system. To get around this I run a small Python script on my always on Xubuntu desktop PC that performs a few functions by subscribing to various MQTT topics, one of which is generating speech. This script also links MQTT to an LED matrix display connected via serial and provides a system for playing sounds, eg. send a payload of redalert.mp3 to the topic notify/sound to get a Star Trek TNG red alert sound. It also allows me to control the master volume via MQTT and operate some basic media player controls.

Integrating Ivona speech into this was easy thanks to the Pyvona Python wrapper for Ivona.

Installing Pyvona is easy:

1. Make sure you have the requests and pygame packages installed
2. Clone the Pyvona Github
3. Run python setup.py install

To use it at its simplest you just need to do:

import pyvona
v = pyvona.create_voice(‘access_key’, ‘secret_key’)
v.speak(‘Hello world’)

Changing the access_key and secret_key for the ones you will get from the Credentials section of your free Ivona account.

You can also specify which Amazon data centre to use, setting it to the nearest one for the lowest latency:

v.region = ‘eu-west’

You can also select which of the many Ivona voices to use:

v.voice_name = ‘Salli’

I’ve uploaded my mqtt.py script to Github here, it’s pretty specific to my requirements but may be of use as a starting point for others.

I’ve used Asterisk at home since around 2004, originally using a clone of a Digium FXO card and later a Sipura SPA-3000 (later owned and branded by Linksys) to interface to my landline. When that server decommissioned itself (with a bang and bad smell) a year or so ago I switched over to the Asterisk based FreePBX on a Raspberry Pi (using the RasPBX distro) but still using the old but perfectly serviceable SPA-3000. It’s rare that anyone I want to speak to calls me on the landline these days (hi Mum!) but I need to keep it active for my BT Infinity fibre broadband so I may as well have something connected to it. Most of the calls I do get on it are junk so I have Asterisk set up to only ring the phones for a specific set of callers and anyone else just gets dumped straight to voicemail or rejected.

On the old server I had set up various extensions that I could dial to perform tasks or drop me into a home automation menu if I called home from my mobile but it never really got any use so I haven’t bothered reimplementing that but one thing I did want to do was as feed incoming call info (caller number and time and date) into MQTT so I could log it and create notifications or events based on a particular callers numbers using Node-RED.

AGI the “Asterisk Gateway Interface” was obviously the way to do this and it turned out that someone has made this very easy by creating an agi-mqtt bridge.

Setting this up was a doddle:

1. Clone the agi-mqtt Github into a suitable location on the Asterisk box, I put it in /opt/agi-mqtt/
2. Copy mqtt.cfg.sample to mqtt.cfg and edit it to set the details for your MQTT server.
3. Make sure the mqtt python script is executable
4. Edit /etc/asterisk/extensions_custom.conf and add:[from-pstn-custom]
   exten => _X.,1,AGI(/opt/agi-mqtt/mqtt,/opt/agi-mqtt/mqtt.cfg,calls/pstn-in)

Obviously changing /opt/agi-mqtt/ for the location you used to install agi-mqtt and calls/pstn-in is the topic you want to send the call info to.

Then in Node-Red you can parse the number from the call data passed into the payload, this could just be a simple function to output the caller number such as:

var calldata = JSON.parse(msg.payload);
msg.payload = calldata.callerid;

I do a bit of translation of numbers to names for the select group that might ever call me on my landline so that voice and display notifications use their name instead of the number. I also log all calls to a text file, mainly so I can look at it once in a while and be amazed at all the phone spam I (didn’t) get.

Landlines; The sooner I don’t need one for my internet connection, the better.

I mentioned in the last post that I send all but a select few callers on my landline straight to voicemail but that’s actually no longer true. Thanks to a casual comment by @ichilton on Twitter I’ve recently switched to diverting calls from unknown numbers to Lenny.

Lenny who? Lenny is an Asterisk dial plan which together with a set of very convincing recordings works as a bot to fool telesales callers into thinking they are talking to a real person. Lenny will answer then wait for the caller to speak and when they stop he moves on to the next recording, it really is very convincing and there are some great recordings of people having lengthy conversations with him on this YouTube channel.

Lenny is very simple to set up, you can find the voice files attached to this forum post and full instructions for setting it up here but briefly you just need to add the following dialplan into your /etc/asterisk/extensions_custom.conf

[from-internal-custom]
;# // BEGIN Lenny Remake
; version 0.3.2 copyright: none claimed. Enjoy!
exten => 53669,1,Answer
exten => 53669,n,Set(TIMEOUT(absolute)=600)
exten => 53669,n,Set(MACHINE=0)
exten => 53669,n,Set(OPTION=5)
exten => 53669,n,Set(TALK_DETECTED=0)
exten => 53669,n,Set(RECORDING=${UNIQUEID})

exten => 53669,n,MixMonitor(/tmp/Lenny/${RECORDING}.wav)
exten => 53669,n,NoOp(Recording will be available: /tmp/Lenny/${RECORDING}.wav)
;exten => 53669,n,Playback(en/this-call-may-be-monitored-or-recorded)

exten => 53669,n,Gosub(playit(Lenny1))
exten => 53669,n,Gosub(playit(Lenny2))
exten => 53669,n,Gosub(playitonce(Lenny3))
exten => 53669,n,Gosub(playitonce(Lenny4))
exten => 53669,n,Gosub(playitonce(Lenny5))
exten => 53669,n,Gosub(playitonce(Lenny6))
exten => 53669,n,Gosub(playitonce(Lenny7))
exten => 53669,n,Gosub(playitonce(Lenny8))
exten => 53669,n,Gosub(playitonce(Lenny9))
exten => 53669,n,Gosub(playitonce(Lenny10))
exten => 53669,n,Gosub(playitonce(Lenny11))
exten => 53669,n,Gosub(playitonce(Lenny12))
exten => 53669,n,Gosub(playitonce(Lenny13))
exten => 53669,n,Gosub(playitonce(Lenny14))
exten => 53669,n,Gosub(playitonce(Lenny15))
exten => 53669,n,Gosub(playitonce(Lenny02))
exten => 53669,n,Gosub(playitonce(Lenny03))
exten => 53669,n,Gosub(playitonce(Lenny06))
exten => 53669,n,Gosub(playitonce(Lenny08))
exten => 53669,n,Gosub(playitonce(Lenny09))
exten => 53669,n,Gosub(playitonce(Lenny10))
exten => 53669,n,Gosub(playitonce(Lenny14))
exten => 53669,n,Playback(en/tt-monkeys)
exten => 53669,n,Hangup

exten => 53669,n(playit),NoOp(Lenny speaks and repeats until reponse)
exten => 53669,n,Set(LOCAL(lennyclip)=${ARG1})
exten => 53669,n(oncemo),Set(TALK_DETECTED=0)
exten => 53669,n,Background(lenny/${lennyclip})
exten => 53669,n,AMD(2500,1500,800,5000,100,50,3,256)
exten => 53669,n,NoOp(${AMDCAUSE})
exten => 53669,n,GotoIf($["${AMDCAUSE:0:17}"="INITIALSILENCE-25"]?reststop)
exten => 53669,n(mach),WaitForSilence(700,3)
exten => 53669,n,Goto(humn)
exten => 53669,n(reststop),WaitForSilence(800,2)
exten => 53669,n,Goto(oncemo)
exten => 53669,n(humn),Return

exten => 53669,n(playitonce),NoOp(Lenny speaks once)
exten => 53669,n,Set(LOCAL(lennyclip)=${ARG1})
exten => 53669,n(noresponse),Background(lenny/${lennyclip})
exten => 53669,n,AMD(2500,1500,800,5000,100,50,3,256)
exten => 53669,n,NoOp(${AMDCAUSE})
;exten => 53669,n,GotoIf($["${AMDCAUSE}"="INITIALSILENCE-2500-2500"]?noresponse)
;exten => 53669,n,GotoIf($[${AMDSTATUS}=HUMAN]?humn2:mach2)
exten => 53669,n(mach2),WaitForSilence(2000,1)
exten => 53669,n(humn2),Return

exten => 536691,1,NoOp(Rerouting inbound call...)
;exten => 536691,n,Flite("After the beep, enter extension or press pound for Lenny.")
;exten => 536691,n,Read(SENDTO,beep,7)
;exten => 536691,n,GotoIf($["foo${SENDTO}" = "foo"]?5:6)
exten => 536691,n,Set(SENDTO=53669)
exten => 536691,n,System(echo "Channel: local/${SENDTO}@from-internal"> /tmp/lenny.call)
exten => 536691,n,System(echo "MaxRetries: 0">> /tmp/lenny.call)
exten => 536691,n,System(echo "RetryTime: 3">> /tmp/lenny.call)
exten => 536691,n,System(echo "WaitTime: 30">> /tmp/lenny.call)
exten => 536691,n,System(echo "Context: bridgit">> /tmp/lenny.call)
exten => 536691,n,System(echo "Extension: 4">> /tmp/lenny.call)
exten => 536691,n,System(echo "Priority: 1">> /tmp/lenny.call)
exten => 536691,n,System(mv /tmp/lenny.call /var/spool/asterisk/outgoing)
;# // END Lenny Remake

Copy the audio files to /var/lib/asterisk/sounds/lenny and make sure the directory and contents are owned by the asterisk user & group.

Reload the Asterisk dialplan with: asterisk -rx “dialplan reload”

and then you can check it is working by dialling extension 53669.

You can then divert any unwanted calls to this extension to have some fun. I did this by creating a custom extension in FreePBX with a destination of local/53669@from-internal and making this the default route for unknown numbers coming in via the PSTN trunk.

To get call recordings emailed to yourself you can use the following shell script called from cron, you’ll want to make sure you have lame and the mime-construct packages installed.

email="email@example.com"
subj="Lenny Recording $(date)"

cd /tmp/Lenny
for i in *.wav; do
if [ -e "$i" ]; then
file=`basename "$i" .wav`
lame -h -b 64 "$i""$file.mp3"
rm "$file.wav"
/usr/bin/mime-construct --file-auto "$file.mp3" --to $email --subject "$subj"
rm "$file.mp3"
fi
done

So far I haven’t recorded anything of interest, it seems most the telesales calls I have been getting are pre-recorded messages but as soon as I get something good I’ll upload it.

Another post I’ve been meaning to write for a long time. I finally got my Rigidbot 3D printer in August 2014 some 9 months later than the estimate but I was one of the lucky ones, many had to wait a lot longer and some have even had to pay extra for delivery, having already paid it once as the company completely ran out of funds. I am very happy with the printer though, I’ve printed all kinds of things since I’ve had it and it has produced some great results.

One of the main things I had in mind for it was printing customised enclosures for my electronics projects. I’ve used a variety of off the shelf cases for my indoor TinyTX and Tiny328 sensors, my favourite being the Evatron EN30W sensor case but I really wanted to design something of my own.

After a few aborted attempts using other 3D CAD packages I discovered the joys of OpenSCAD an open source 3D CAD package that allows you to write code to construct the 3D model instead of the more traditional graphical model. When I had first seen this tool I thought it seemed wrong, to approach what I saw as a graphical problem in a programmatic way but in retrospect it makes total sense as we are dealing with precise numbers here and being able to code parts in modules allows you to easily turn various parts of the design on and off easily and scale the whole design just by changing a few defines as well as easily reuse modules in other designs. Once you get in to the right mindset it really is good.

At the top of the code window you can see there are some defines to select whether it should render just the top or bottom of the case or the full thing, whether there should be vents in the top and how long they should be, if a square or round cut out is required for a cable or sensor to stick out of and if mounting holes are required in the back half of the case.

The next section sets the width and length of the PCB section and the battery holder section so I can set which board I am using and whether it is a single or double battery holder.  Then it goes on to configure how long the vents on the top should be and the dimensions and positions of the cut outs if required.

Once happy with that it’s just a case of exporting it as an STL file which I then process with Slic3r and send onto Octoprint running on a Raspberry Pi connected to the printer ready to be printed.

This prints really well on my printer, there are no clips to hold it together as such, the extended pieces in the corners are just made to a tight enough tolerance that they grip the top of the case as it is pushed on. I’ll probably tweak this a bit more over time but it does the job as it stands, the dimensions can be adjusted but as noted in the code comments there are some issues with the PCB supports not scaling properly once the PCB length gets over 46mm.

I’ve put the code on my Github here if anyone fancies giving it a try.

Stevenson Screen

One of the early prints I did was this Stevenson screen which is an enclosure for outdoor sensors, the principle is to shield the sensors from direct heat radiation from outside sources while still allowing air to circulate freely. I used the STL files from Thingiverse here, if I recall correctly it took over 20 hours to print all the parts (over several days). It consists of four identical middle sections (more or less if you want it bigger or smaller), a top section and the base section. It’s a well designed object, each piece clips together very well and I was lucky enough to have a piece of plastic pipe that it fitted to perfectly (thanks to the random fly tipper that threw it over my back fence!).

I printed it using PLA which being biodegradable isn’t ideal but it was all I had. I wasn’t sure how well it would stand up to the weather but after 12 months it doesn’t look any different than it did when I first put it out there. I did think of treating it with something to protect it but decided to leave it as an experiment to see how it fares over time.

Inside the box mounted below it is one of my Tiny328 boards and four AA batteries connected to the regulated input, this is connected to a DHT22 temperature and humidity sensor which is suspended from the top of the stevenson screen so that it is positioned roughly in the middle.

Below are some pictures of it coming together and there is also a timelapse video here of one of the sections being printed.

PIR housing

One other related item that I’ve printed is this nice compact housing for the cheap BIS0001 based PIR motion sensors. I got this one from Thingiverse here and there are two versions available, one with square edges and one more rounded, I’ve used the rounded one.

During my tinkering over the past two weeks, I hit a snag while trying to hook up the LPC824 µC to the Arduino IDE. Nothing spectacular or insurmountable, but still…

This week, I have two articles for you, explaining what this is all about:

• Serial uploads vs flow control– Wed
• Revisiting existing chips and code– Thu

Warning: there are going to be some changes w.r.t. where I’ll be going next…

(For comments, visit the forum area)

Not many people will take some time to learn how some the things that they use everyday work. For example, only few women would actually devote even just a little of their precious time to know how a hair dryer works in order for them to deal with some problems concerning their hair. This might be the right opportunity to provide some helpful knowledge about how this simple machine works.

The Difference between Past Hair Dryers and their Upgrades

The very idea of the way a hair dryer works is that hot air comes out from it. But that was for modern hair dryers today. Before, dryers actually work by sucking air right inside on its body, with the hope of eventually drying wet hairs.

How A Hair Dryer Works and the Science Behind It

Upon application of power to the hair dryer, the fan installed inside it will spin enabling the dryer to have a supply of air which will pass through wire coils that will heat the air. The result is a hotter air that can be directed to the hair from a safe distance. The hot air speeds up the process of water evaporation, thus ridding your hair of moisture and making it dry faster. The process seems pretty much simple, but it takes a lot more of science to ensure that this process is carried our properly every time a hair dryer is used.

Comparing It to Traditional Methods of Hair Drying

Modern hair dryers have repeatedly gained advantage every time comparison between them and traditional methods of hair drying are drawn. Visiting sites such as http://www.hairdryersonline.com/ definitely helps a lot of women get the dryers that they want. Perhaps, this is because a lot of people appreciate its fast and more efficient nature, as compared when you repeatedly comb your hair or leave your towel in it for a long period of time just to get rid of its moisture.

As announced last week, I’ll be switching (pouring?) my efforts into a new series of µC’s for a while, so there’s quite a bit of work ahead to get going, and I really don’t want to dwell too much on the basics. The whole point is to get further, not redo everything and get nowhere!

So for this week, there will be a whole slew of posts. As usual, each next post will be ready on successive days, as I figure it all out and try to stay ahead of the game :)

• STM32F1’s and all that jazz– Wed
• Details of the STM32F103– Thu
• So many boards, so many µCs– Fri
• The Arduino IDE with STM32– Sat
• A few simple sketches for ARM– Sun
• Meet the RF Node Watcher– Mon

Here is a sneak preview of the main character in this exciting new adventure:

(For comments, visit the forum area)

I’ve mentioned my plans for this project during the IoT hangout session few months ago, it has finally materialized as working prototype. The blocker so far was the lack of ESP8266 RFM69 driver and free time on my end, so I’ve teamed up with Andrey Balarev to solve this. Andrey is an IoT enthusiast + embedded systems developer and has done excellent job in porting LowPowerLab’s RFM69 library for the ESP8266. He spent few weekends staring at the oscilloscope, re-writing SPI library code and managed to solve a number of challenges to get this library going. I’ve bundled his driver code with MQTT to get a beautifully working prototype that forwards RFM69 traffic to MQTT and vice versa. Few screenshots of the setup:

Some folks probably ask why the RFM69 and not RFM12B and why LowPoweLab’s library and not Jeelib, I’ve outlined my view on that before here. Basically with Jeelib we are forcing the RFM69 in artificial compatible mode and not taking fill advantage of the chip.

What I plan to add as functionality is payload serialization configuration, payload field name configuration and RPN based signal processing configuration so that JSON could be constructed/deconstructed from payloads in both directions.

It will be a replacement for the RFM2Pi project, a much more advanced standalone M2M gateway.

I’ll build few PCBs and you will be able to grab some from my store as well. RFM69 library code will be shared at that point.

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When dealing with ARM µCs and boards based on them, there’s always one big elephant in the room: how to upload software to them, and how to talk to them via serial or USB.

The available options, choices, trade-offs, and even just their properties can be staggering. This week’s article series is about what the problem is, an overview of the many different ways to address them, and how to get started with the minimal fuss and/or minimal cost.

On the menu for this week are four dishes, served on a daily basis:

• Most bare µCs are clueless– Wed
• Lots of chickens and eggs– Thu
• Bootstrapping a boot loader– Fri
• Making a Black Magic Probe– Sat

Fortunately, we’ll need very little to get going. We can pull ourselves up by our bootstraps!

(For comments, visit the forum area)

The comments to my last blog post got me thinking if I had chosen the right RFM channel at home, obviously if the channel is noisy that directly affects reception and increases the error rates. I use the default 868Mhz setting for the RFM12B/RFM69s at home and decided to check if the channel is clear from other transmissions. I remembered seeing a RFM12B spectrum analyzer project over at Jeelab some years ago, and 5 minutes later was running the spectrum analyzer using one of my Funky v3s equipped with a 868Mhz RFM12B.

The result is as follows:

There are strange peeks at 864 and 870Mhz, the signal level is weak, less than -97dBm, but other than that it is very clean spectrum. And no wonder, I live in a small suburban village. That’s good result, the default 868Mhz band seems clear. I was curious about the two peaks and took another scan at my office in downtown Sofia, the result is much noisier spectrum, but oddly the peaks are there too, in fact couple more are clearly visible as well plus a faint trace of third one:

Most probably these are harmonics from DVB-T or other strong signal, but the area around 868Mhz seems clear both in the city and at home. Good to know. Scanning the spectrum and choosing a free channel to use is an effort well worth when initially setting up a wireless sensor network.

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