Arduino Signals II - Video and Flickering
I’ve continued working on the code to drive LED signals with an Arduino. I’d previously discussed my approach, and provided the code I was using at that time. I’ve learned a bit since then, and cleaned up the code significantly. I’ll provide a link to the current example program at the end of this post.
Fundamentally nothing has changed. I’m still planning to use NJI common-anode SMD LED signals (in fact, I’ve ordered them). What I did do was change the code so that a “bank” of two signals would always have both lit (meaning two of the four LEDs would be on when the bank was active) so that I could get through the full set of signals more quickly. One reason for this has to do with video camera shutter speeds. I think it’s worth saying a bit about that issue.
I’ve also made some changes to make the time wasted in turning the pins on and off less, since at these speeds that is becoming a significant percentage of the total LED cycle, and I need that time for the eventual Tram Controller program to be doing other things. These changes consisted of adding a library that provides faster versions of writeDigital and pinMode, as well as keeping track of what state pins are on, and not trying to change them unless the new state differs (this got rid of a number of “change disabled pin X to disabled” changes).
In my test program, when cycling at 8 milliseconds, I’m now spending just a quarter millisecond changing those pins with three banks (6 signals) in use. My One Point Five Meter line will only use four signals, as it doesn’t have the extended double-track section of the full Tram Line, which needs six. And so it will run even more efficiently. Read More...
Fundamentally nothing has changed. I’m still planning to use NJI common-anode SMD LED signals (in fact, I’ve ordered them). What I did do was change the code so that a “bank” of two signals would always have both lit (meaning two of the four LEDs would be on when the bank was active) so that I could get through the full set of signals more quickly. One reason for this has to do with video camera shutter speeds. I think it’s worth saying a bit about that issue.
I’ve also made some changes to make the time wasted in turning the pins on and off less, since at these speeds that is becoming a significant percentage of the total LED cycle, and I need that time for the eventual Tram Controller program to be doing other things. These changes consisted of adding a library that provides faster versions of writeDigital and pinMode, as well as keeping track of what state pins are on, and not trying to change them unless the new state differs (this got rid of a number of “change disabled pin X to disabled” changes).
In my test program, when cycling at 8 milliseconds, I’m now spending just a quarter millisecond changing those pins with three banks (6 signals) in use. My One Point Five Meter line will only use four signals, as it doesn’t have the extended double-track section of the full Tram Line, which needs six. And so it will run even more efficiently. Read More...
Plywood and Sawdust
19 September 2013 23:34 Filed in: Construction
Building a new railroad starts with the planning, obviously, but it doesn’t really feel like it’s started until the sawdust starts to fly. Last week, after much re-thinking and dithering, I bought some plywood and let fly. Construction has officially begun on the One Point Five Meter Line (and I really need to think up a name for it). The concept has changed slightly since I first wrote about it a month ago. Then it was going to be three small sections (or maybe two) that connected together, and I was still thinking of a high-level platform line that would work for either light rail vehicles like my Setagaya trams, or single-car commuter trains.
The current concept, which could still be modified, uses low-level platforms and street track, and is more suited to light rail vehicles like the Portrams I covered last time. But what won’t change is the shape: that’s cut, glued and painted, as you can see above. It’s a single assembly, one foot (30 cm) wide and five feet (1.5m) long, standing six inches (15 cm) tall at the high end.
Read More...
The current concept, which could still be modified, uses low-level platforms and street track, and is more suited to light rail vehicles like the Portrams I covered last time. But what won’t change is the shape: that’s cut, glued and painted, as you can see above. It’s a single assembly, one foot (30 cm) wide and five feet (1.5m) long, standing six inches (15 cm) tall at the high end.
Read More...
Two Trams
A “tram” is a light rail vehicle. The word is British English; American’s still say “trolley” even though our light rail systems haven’t used trolley poles in decades. But it’s a word also used by the Japanese (who often borrow foreign words, either for marketing reasons or just because they like the sound).
The Toyama Light Rail line, a company jointly owned by the Toyama city government and some other investors, operates light rail vehicles over a former freight railway running between the city center and the waterfront. This is officially known as the Toyamakō Line, but the locals know it as “Portram” (for Port Tram), and the vehicles introduced in 2006 have come to be known by that name. There are seven of them, all of basically the same design but in different colors. A separate railway operates a city-center ring using similar vehicles, known as the Centram (“Central Tram”, I presume).
Tomytec, the parent company of Tomix, has been making models of these as part of their Railway Collection series since about 2009. These are intended to be collectibles for display, and they’re just empty shells. They cost around US$15 - US$20. But Tomytec also makes a motor unit that replaces the underbody, the TM-LRT01, which goes for around US$30. So for under $50, you can have an operating model. They’re not as nice as Kato’s Portram models, which sell for about US$85 in Japan, but they’re still quite good models.
I had been thinking about getting one of these, just to see how they compared with the Portram (I have one of Kato’s Centram models), but hadn’t gotten around to it. Then, while I was wondering what I’d run on my One Point Five Meter Line layout, I saw this new pair of them and decided that a model tram with a replaceable motor was the perfect thing for a layout that may do a lot of running back and forth. I ordered the pair, and two of the motors (thankfully those were available; they often sell out and can’t be found for months on end).
Read More...
The Toyama Light Rail line, a company jointly owned by the Toyama city government and some other investors, operates light rail vehicles over a former freight railway running between the city center and the waterfront. This is officially known as the Toyamakō Line, but the locals know it as “Portram” (for Port Tram), and the vehicles introduced in 2006 have come to be known by that name. There are seven of them, all of basically the same design but in different colors. A separate railway operates a city-center ring using similar vehicles, known as the Centram (“Central Tram”, I presume).
Tomytec, the parent company of Tomix, has been making models of these as part of their Railway Collection series since about 2009. These are intended to be collectibles for display, and they’re just empty shells. They cost around US$15 - US$20. But Tomytec also makes a motor unit that replaces the underbody, the TM-LRT01, which goes for around US$30. So for under $50, you can have an operating model. They’re not as nice as Kato’s Portram models, which sell for about US$85 in Japan, but they’re still quite good models.
I had been thinking about getting one of these, just to see how they compared with the Portram (I have one of Kato’s Centram models), but hadn’t gotten around to it. Then, while I was wondering what I’d run on my One Point Five Meter Line layout, I saw this new pair of them and decided that a model tram with a replaceable motor was the perfect thing for a layout that may do a lot of running back and forth. I ordered the pair, and two of the motors (thankfully those were available; they often sell out and can’t be found for months on end).
Read More...
August 2013 Status - a Retrospective
And not only another month, but another year has passed. Not much happened in August; as I mentioned last time I’ve mostly been working on the Arduino project. So this month’s post will focus on the past, but will also look forward to the future.
This month marks the fourth anniversary of Sumida Crossing, dating things from the start of construction. Planning actually started earlier, around June of 2009 in earnest although there had been a lot of thought prior to that. And the first real train didn’t run until early 2010 (unless you count a test on a loop of temporary track). And actually, although the first post in this blog dates from September 16, it wasn’t actually online until the end of November. Prior to that I’d been working on the initial version of the website offline, and hadn’t bought the domain name or space on a server until I judged it ready. I don’t think it even had a name before November; I’m pretty sure I made that up when I bought the domain name.
Read More...
This month marks the fourth anniversary of Sumida Crossing, dating things from the start of construction. Planning actually started earlier, around June of 2009 in earnest although there had been a lot of thought prior to that. And the first real train didn’t run until early 2010 (unless you count a test on a loop of temporary track). And actually, although the first post in this blog dates from September 16, it wasn’t actually online until the end of November. Prior to that I’d been working on the initial version of the website offline, and hadn’t bought the domain name or space on a server until I judged it ready. I don’t think it even had a name before November; I’m pretty sure I made that up when I bought the domain name.
Read More...
