Going way back – A digital clock that pretends to be analog

It is currently 3 hours 16 minutes

It is currently 3 hours 16 minutes

Going way back to 2006 actually, to my very first electronics project, a digital clock with an analog twist. I had very little experience in programming let alone electronics and back then, user-friendly prototyping platforms were not that common and mostly underground; the arduino had only came out the year before.

The clock with its faceplate removed

The clock with its faceplate removed

For many evenings in my dorm room I battled with a bunch of components and a serially programmed Microchip PIC16F628. I recall having loads of trouble getting inputs to the chip functioning, with the minutes and hours buttons activating or refusing to work with a mind of their own. The internet was not of much help but in the end I figured it out: pull-down resistors. No wonder I could not find anything on the subject, for someone with the least bit experience in electronics, it’s one of the most elementary concepts, akin to trying to troubleshoot a TV that’s not plugged in. For beginners attempting to learn electronics by themselves, its nothing but trivial.

Eventually, I succeeded in putting a working clock together on the breadboard that I had. Back in my basement over the next break from school, I soldered the whole thing on a perfboard and equipped the circuit with a face plate. The programming is rudimentary, the circuit is much less than optimal and in spite of the 32kHz watch crystal, there is still a bit of drifting but I could not have asked for a better learning experience. Some LEDs have burnout, but even after those years, it’s still  doing a fine job at reminding me that time is ticking.

 

 

Toughts on traveling

Note to reader: this is a piece that has been sitting in my drafts folder for about a year. I no longer remember why I did not publish it back then. It could have been the transpiring pretentiousness. However, now that I have hung up my backpack for a while, I have found it to resonate very well with the new life that I am living.

Nick from Utila told me particularly insightful story he had heard many years ago back in Belgium. It was a rich old man giving a piece of wisdom to a journalist on TV and it went like this:

True adventure has three requirements: energy, time and money. As a young person, you have plenty of time, loads of energy but no money. As you progress into adulthood, you start earning money and still retain most of that youthful energy you had but for many reasons such as family or professional obligations, the clock eludes you.. You age further, you eventually reach retirement, which affords you with much freedom and richness you gathered during your productive life but sadly, the energy has disappeared.

It sounds like a fatality, but upon careful inspection, there is a moment, even a brief one, where the conditions for adventures are fulfilled: the twenties (or more generally celibacy). You have no (real) responsibilities so time and energy are plentiful. You most likely have studied and held a well paying job for a while so money is not an issue. Go.

I’m not saying that there cannot be anything afterwards, quite the contrary, at least I wish that for myself, but as life progresses, it becomes less likely that you will embark on a crazy trip across the globe. For the lack of energy perhaps, but chiefly because you have lost the interest, you’ve “grown’up” to other things; so many decades spent sleeping on a comfortable bed have made you soft. Fear not though, there is plenty left to do and many more experiences to enjoy, the richness of life is infinite, but there are certain things you wish you would have done when you were younger. Playing your cards well is not putting yourself in dangerous situations just for the sake of it, its more like making sure you’ll live on without regrets.

At all stages or life, adventure is exposure, to new things, to hardships, to solitude. Humans do not like change, but it is change that made us humans. The brain only adapts and thinks if there is pressure on it to do so and putting yourself in new environments does just that. La meilleure école, c’est le voyage (the best school is travelling), but on those benches, nothing you learn could ever be summarized in a textbook, it is not discrete knowledge, it’s experience in it’s purest form. It makes you a better person, but more so it gives you an opportunity for introspection and growth not found elsewhere.

Carpe diem as they say.

The keyMote: a simple wireless remote for computers

The keyMote

The keyMote

Note: this post about an electronics project has been sitting as a draft since 2011 so some of its content might appear outdated. Regardless, I’ve been using the device since then so I figured I should commit it to posterity.

To my computer, its simply a USB keyboard, nothing less, but to me its a remote I can use on any platform with no line of sight. I decided to name it the keyMote. Sounds a bit odd to my ears but its a fitting name.

Here is how it works. There are two parts to this system, the remote, which is battery powered, and the base, which is hooked up to a computer. The remote is a simple keypad (In the case of the prototype, its a numeric keypad, but really, it could be any interface) with a transmitter hooked up to it. The base, the other end, is a receiver with USB Human interface device functionality, in other words, a vanilla USB keyboard. When a button is pressed, the remote sends the identifier of that button to the base which then looks up in a table the keystrokes this identifier is mapped to and sends those to the computer via USB. What button is mapped to what keystroke is entirely configurable using a serial terminal interface (shell) to the base. It can be anything, Ctrl-C, Alt-Shift-F, PageUp, etc. Getting it to interface with your program is then simply a matter of configuring keyboard shortcuts.

The use case

Here is the actual use case that spawned the idea. I was doing some plumbing work in my kitchen with the computer playing songs in the background. It then hit one in the playlist that I especially hate (but keep for nostalgia), but I was in no position to change it as it would have implied bending out of underneath my sink, walking to my computer and then hitting Ctrl + Shift + Right to skip to the next tune. I use Linux and at that time, the media buttons on my keyboard were not operational, I knew very few remotes would work on my platform and finally, I had no line of sight with the computer, so infrared was out of the question. Agreed, a wireless keyboard would have done the trick, but those tend to be limited in range, and well, they are still keyboards, so you have to do the key combinations yourself and are somewhat cumbersome to lug around. So I thought: Why not get something that will emulate my hands typing the keyboard shortcuts?

I looked around for possible off-the-shelf solutions, but none of them were well supported under Linux; basically they all required drivers and were proprietary and as we all know, anything with a driver is dependent on company support an will get dumped sooner of later. The keyboard idea was starting to get some traction. It was the obvious medium to go with, the USB human interface device standard has been around for a decade or so and will likely stick for a few more but more importantly, it is understood by most OSes. Failing to come across anything that would suit my purpose, I set out to develop one from scratch and after a bit of work (or a lot, depending where you come from), I had what I wanted: a simple, rugged self-contained system with no drivers attached, plenty of battery life and a way to make it type whatever I want. Currently, its mapped to my MP3 player, sound controls, Video player controls and some programming IDE functions. It could very well launch applications, toggle the visibility of certain windows (via the window manager), start scripts; it can do anything a keyboard can do.

The system

The main hardware components are an arduino, a wireless receiver and transmitter pair and another microcontroller hooked up to a battery in the remote. I started off with trying out wireless communication on the arduino IDE but soon converted to C/C++ for the added flexibility once I was past figuring out the libraries.

Base

The base software is mainly an interface between two libraries, VirtualWire and V-USB along with a shell to configure the mapping between remote key codes and key strokes. VirtualWire is a library that makes exchanging bits (a lot harder than the datasheet implies, what you send on TX is quite what you get on RX) between vanilla wireless interfaces very straightforward. V-USB is a marvelous implementation of the USB protocol on the AVR using nothing but bit-banging. It’s quite limited in capacity but it’s extremely lean and makes USB accessible for anyone with the patience to understand the protocol. While the actual serial shell is a fair chunk of code, it is needed only for configuration, so this project is mainly composed of glue code and basic electronics. The arduino’s USB connector is used for serial shell functionality, where using commands it is possible to consult statistics about the system, get debugging data, but more importantly map key Ids to key strokes. The other USB connector is the actual keyboard.

The base schematic

The base schematic

Since I had an arduino to spare, I decided to implement the USB and wireless interfaces as a shield rather than build a specific circuit. Really, the only hurdle was the weird spacing between pin 7 and 8 (why?), but that got solved by soldering angled headers to the side of the perfboard at an offset with the holes they would normally fit in. The wireless receiver was a breeze to connect but the USB interface was slightly more complex, with a couple of zener diodes and resistors to get the correct line levels.

Two versions of the base were created but they only differ in the way they look.

Remote

The base is mostly software but the remote is mostly electronics. The code is essentially a loop that intercepts keypad presses and sends them out through the transmitter to the base. Since it’s battery powered, the complexity of the firmware lays essentially in the power management code as the electronics cannot be left on running at full power all the time.

Remote prototype schematic

Remote prototype schematic

I built two different versions of the remote. The prototype which used another ATMega328P (same MCU as the arduino) featured an off-the-shelf keypad and a USB connector with a MAX 1555 for charging. The MCU is left in its deepest sleep mode all the time and is only waken up when a key press occurs. As a result, power consumption is in the order of nano amperes which yields a battery life of a couple months under normal usage when hooked up to a 900 mAh LiPo battery.

Remote version 2 schematic

Remote version 2 schematic

The second version goes even further into increasing battery life. The ATMega328P, overkill for this application, is replaced with an ATTiny84 and the keypad interface is hooked up a circuit that turns on the micro controller and the transmitter from a fully off state only when a key is pressed. It’s using the same battery as the prototype but the power usage is so minute that after close to two years I have not yet exhausted the battery and measuring the drain is beyond my multimeter’s range. Granted, usage has been on and off due to me leaving for extended periods of time but still, that’s a pretty decent statisctic. So much so that I had plans to convert it to a solar cell and supercapacitor design but sadly, all my prototyping efforts led to failure.

The result

It was quickly put together and yielded a result of fairly high quality and convenience for the effort. I’m not saying there is no room for improvement, but it was refreshing to do a project that was not plagued by unforeseen complexity and feature creep. I’ve been using both remotes for the past two years and have been getting months of battery life for the prototype and for its successor, well, it’s still running after two years. Range wise, I can send commands at a distance of about 10 meters through several walls so it more than sufficient.

Since I have no plans to revisit the project in the near future, I’m publishing the source code and the schematics (made with gEDA) up for download on a GNU GPL license. Take note that some of the third-party libraries use a different license which is specified in their respective folders. Should you have any questions, do not hesitate to reach me through the comments or the contact page.

Vietnam – the end

Like this telephone pole, my mind is a mess.

Like this telephone pole, my mind is a mess.

Not much happened during those two days that I had to kill in Ha Noi before my flight. My hostel, shitty; the city, visited for the most part; the weather, rainy and my overall motivation level, low. I did check out the museum of fine arts, the Temple of Literature and the botanical garden but otherwise, my days were spend wandering aimlessly around the city and working in front of my computer. My thoughts were occupied with the coming med school interviews and planning for a life that would potentially change drastically in the near future. It seemed all the accumulated fatigue of the last couple of months had now all came down on my body and mind, this trip was over.

I had a few interesting encounters but not of them led to friendships that would endure past an hour or two. One of those was at a nearby bar, where for the better part of the night I conversed with a Vietnamese barmaid with the aim of improving her English. Another one was with Antoine, the French motorcycle enthusiast I met back in Sa Pa, but sadly, we only had a few minutes to catch up, he was on his way to the bus. Turns out he did not go to the north, the day after he had left, the seemingly unending flow of trucks got the best of him and he turned around.

Monday night I arrived at the airport quite early to find it already overcrowded with hordes of travelers but I managed to find a quiet spot to sit down and read in the arrivals area. A flight to Tokyo, a couple of hours spent waiting at the airport; across the Pacific to New York, more waiting and then I landed in Burlington, Vermont, where a friend picked me up with my car to drive me to Montreal. It was a long journey, but thankfully I was flying with Japan Airlines and got the exemplary service that is to be expected of anything Japanese plus a pretty nice in-flight entertainment system aboard a recently refurbished plane.

Thoughts on Vietnam

I have not seen all of South-East Asia, but so far I can confidently say that Vietnam is my favorite place of them all, You buy something?, motorbike?, traveling around can a serious pain in the butt on occasions, but everywhere in between, you come across genuinely nice encounters. Then again, you have to realize where the Vietnamese come from as a nation and instantly you become more tolerant towards the constant harassment. Landscapes are sort of the same story, the cities and the countryside can be downright ugly, Vietnam remains a poorer Asian country, but not far out lies absolutely spectacular sights of rice paddies surrounded by mountains and ethnic villages of wooden houses and water buffaloes herds. The still omnipresent communist architecture and propaganda get an honorable mention as well and so does the cultural variety of its people.

It’s exhausting to visit, but it’s well worth the effort, but be quick if you want to go, Vietnam has embraced modernity with both arms and like its neighbors, it’s increasingly capitalizing on tourism of the more destructive type a great deal to boost its economy. For that matter, the country’s principal tourism circuit, already quite limited, is starting to feel bland and denatured. There is still plenty to see and do not very far outside of it, get your own set of wheels and adventure will await around the corner. However, I suspect its only a question of time before the hordes of resort goers get there too.

Motorbike Motorbike in Northern Vietnam – Conclusion

Safe and sound in Ha Noi, its time to reflect back on this exhilarating experience. To put it in short terms, it’s now the benchmark by which I will judge my future travels. I had done other motorcycle adventures in past, but through this one, it has really dawned on me that this is where I get my adrenaline (and though diving too of course) and truly is one of the best ways to enjoy a country and see it more for what it really is. There will surely be more backpacking in the future for me, but I’ve realized that I’m thoroughly tired of public transportation and hoping from hostel to hostel so I’ll definitely attempt to make my future visits to foreign countries more adventure motorcycling oriented. I never came across any close calls. Yes, I brushed on oncoming vehicles countless times and had to swerve to avoid all sorts of animals and obstacles, but that is what driving is like in Vietnam. Otherwise, I was in control of my machine to whole time. It was not for the inexperienced driver and got quite painful and tiring on occasions, but I thoroughly enjoyed every minute of it. Especially in the Ha Giang province, which presented me some of the most beautiful scenery I had ever seen in my entire life.

The route that I took

The route that I took

The Honda Win 100

Really a 107cc, but that does not matter very much because with compression issues, it had trouble moving its own weight on steep hills so I’ll avoid commenting on power. Otherwise, to make things more simple and visual, here is a breakdown of my appreciation of the bike:

Plusses

  • light
  • easy on gas
  • easy to fix
  • inexpensive
  • handles well (when the frame is straight)
  • fun to drive

Minuses

  • very unreliable (the chinese versions at least)
  • vibrates like crazy at high speeds
  • treacherous in emergency breaking
  • parts not that widely available
  • very uncomfortable

This being said, if I ever need another ride in Vietnam, I will stay away from the Honda Wins. The vast majority of those that are on the market around hostels are tourist bikes. They have been up and down the country countless times, were treated badly by their owners and have for sure crashed in their past, at least mine had. 99 % of the people I’ve met while traveling have had breakdowns. There is always a garage nearby, but it remains that the bill adds up to quite a bit over time. Plus, the Vietnamese rarely do a good job at fixing things, they’ll simply mend it so it will run fine for a couple more hundred kilometers and will break again but by this time, you’ll be too far to come back to complain about a repair poorly done. While the Vietnamese themselves used to rely on them a lot and still do so up north, they are moving away towards semi-automatic Honda Dreams, which are much much more reliable, perform better and are more comfortable. They might not be as fun to drive, but they are the workhorses of this country and can take quite a severe beating. Parts will also be readily available even at the smallest most remote garage out there. So if I do come back in this region to bike through Laos and Cambodia, I’ll get a Honda Dream.