One note: You only need one sensor on the receiver! Instead of transmitting 010 you'd transmit an extra "1" before each bit: 101110.
The first bit would be a framing bit (a "start" bit) like in RS232 communications. That starts the timer. (You have a start bit now, but are hiding it under the train!) You don't have to halve the speed to do this. You could add an arm on the front of the train, fixed in the "1" position, slightly higher than the blue pylon so it won't hit.
I'm effectively doing this, (although I didn't think it in this way), because the two sensors are wired in parallel. However the sensors I could find have a working range of a couple of mm at most, so setting one sensor up in a way that would allow the train's protrusion to pass from the blue pylon and reflect on the sensor might be difficult. Perhaps it can be done by separating the IR transmitter and receiver.
Very clever idea! It had not occurred to me. It's interesting how cooperating minds can improve a concept. My original design revolved on the idea of an actuator pushing bits on the train. A friend suggested using a junction.
If you were to use two trains, you would need to build some sort of delay into the inner path
Consider for a second a large checkerboard pattern (alternating red and black). If we are using two trains, one will always take the inner path, one will always take the outer path. However, because the inner path is shorter than the smaller path, eventually the two trains could collide or the inner train could pass the outer one. Using two (or more) trains is a great idea if you can solve that problem
You cannot guarantee that the two trains will have the same speed. Over the course of the contest the train moved sluggishly, until I lubricated the axles of the carriage with some olive-oil from another contestant who was demonstrating the dispersion of molecules in liquids. (You can actually see the difference in the movie. The brightly lit scenes are before lubricating the axles.) Therefore, rather than a simple delay, you would need a mechanism to synchronize the trains .
[1/3] You need to use some real-world objects that express the idea of a mutex or a critical section; in this case the two trains are the two threads that want to use the same critical resource.
So far my idea is to use two turnpikes that are connected to each other, when one is ON, the other is OFF, and vice-versa.
[2/3]The first turnpike is installed at the beginning of the fork; the second one is where the paths are merged (this part between the form and the merging point is the critical section). If one train is approaching the fork while the other one is in the critical section - it will have to wait until the other train leaves the critical section.
[3/3] Another similar example is when you have two light switches for the same bulb; one switch is downstairs, the other one - upstairs. Setting switch#1 to ON changes switch#2 to OFF, and vice-versa.
So, what is needed is a hardware equivalent of XOR.
Last, but not least, it is time to sketch an RFC called "IP over train" :-)
This is brilliant!
One note: You only need one sensor on the receiver! Instead of transmitting 010 you'd transmit an extra "1" before each bit: 101110.
The first bit would be a framing bit (a "start" bit) like in RS232 communications. That starts the timer. (You have a start bit now, but are hiding it under the train!) You don't have to halve the speed to do this. You could add an arm on the front of the train, fixed in the "1" position, slightly higher than the blue pylon so it won't hit.
notupopper 3 years ago
I'm effectively doing this, (although I didn't think it in this way), because the two sensors are wired in parallel. However the sensors I could find have a working range of a couple of mm at most, so setting one sensor up in a way that would allow the train's protrusion to pass from the blue pylon and reflect on the sensor might be difficult. Perhaps it can be done by separating the IR transmitter and receiver.
dspinellis 3 years ago
Very clever. This is a great way to get young minds attuned to computer engineering.
steelystan 3 years ago
Just think. Two trains would double the bandwidth.
fernwood 3 years ago 5
Very clever idea! It had not occurred to me. It's interesting how cooperating minds can improve a concept. My original design revolved on the idea of an actuator pushing bits on the train. A friend suggested using a junction.
dspinellis 3 years ago
If you were to use two trains, you would need to build some sort of delay into the inner path
Consider for a second a large checkerboard pattern (alternating red and black). If we are using two trains, one will always take the inner path, one will always take the outer path. However, because the inner path is shorter than the smaller path, eventually the two trains could collide or the inner train could pass the outer one. Using two (or more) trains is a great idea if you can solve that problem
whatsagoodsn 3 years ago
You cannot guarantee that the two trains will have the same speed. Over the course of the contest the train moved sluggishly, until I lubricated the axles of the carriage with some olive-oil from another contestant who was demonstrating the dispersion of molecules in liquids. (You can actually see the difference in the movie. The brightly lit scenes are before lubricating the axles.) Therefore, rather than a simple delay, you would need a mechanism to synchronize the trains .
dspinellis 3 years ago
[1/3] You need to use some real-world objects that express the idea of a mutex or a critical section; in this case the two trains are the two threads that want to use the same critical resource.
So far my idea is to use two turnpikes that are connected to each other, when one is ON, the other is OFF, and vice-versa.
ralienpp 2 years ago
[2/3]The first turnpike is installed at the beginning of the fork; the second one is where the paths are merged (this part between the form and the merging point is the critical section). If one train is approaching the fork while the other one is in the critical section - it will have to wait until the other train leaves the critical section.
ralienpp 2 years ago
[3/3] Another similar example is when you have two light switches for the same bulb; one switch is downstairs, the other one - upstairs. Setting switch#1 to ON changes switch#2 to OFF, and vice-versa.
So, what is needed is a hardware equivalent of XOR.
Last, but not least, it is time to sketch an RFC called "IP over train" :-)
ralienpp 2 years ago
orginal! amazing!
rustysnoopy 3 years ago
What a really neat idea.
Metaleks 3 years ago
Well done!!!keep up the good work!!!
dgeronikolas 3 years ago
Excellent design, Great explanation.
jordanlwxbox 3 years ago
Ingenious idea and flawless video presentation!
chrislazaris 3 years ago