Vasu Agrawal

vasua@andrew.cmu.edu

Alumni in Electrical and Computer Engineering

ECE and Robotics Junior who loves building awesome things :)

RaspberryFarm

We are building a distributive computation farm out of Raspberry Pi Zeros.

@vasua, @relong

MinesweepAR

The classic game of Minesweeper in (augmented) real life!

@vasua, @relong, @yongyiz, @adbenson

First Person Space Invaders

Because MinesweepAR wasn't hard enough.

@efang, @hliou, @relong, @cli4, @vasua

RaspberryFarm 12 Jan 2016, 12:34 p.m. EST
Working on getting the fans attached to the back plate. The racks are drying nicely.
RaspberryFarm 12 Jan 2016, 2:32 p.m. EST
Finished putting together the case. It's ready to take in some racks now!
RaspberryFarm 12 Jan 2016, 2:38 p.m. EST
Acetone didn't seem to do anything to the paper / junk that we got from the glue, so we'll have to find a more powerful chemical to clean up with
RaspberryFarm 12 Jan 2016, 2:40 p.m. EST
I may also have slightly cracked the acrylic when riveting. Using a hand riveter instead of a pneumatic one didn't change anything either. I think it had something to do with the holes not being aligned properly, but even when I redrilled it nothing changed. Not sure what's going on.
RaspberryFarm 12 Jan 2016, 9:06 p.m. EST
Working on getting the raspberry pis mounted to the racks
RaspberryFarm 13 Jan 2016, 2:37 a.m. EST
We couldn't find a DC barrel jack of the right size to power the USB hub, so we had to rip it apart and desolder the jack and solder on some wires in its place. It took a few tries and I learned more about soldering, 3 more to go! Calling it a night here.
RaspberryFarm 13 Jan 2016, 3:45 a.m. EST
Also wired up all of the fans together. Since we couldn't find any jumpers the size that we wanted, we made our own out of some wire. They work well; all of the fans were powered from the power supply and running smoothly. It looks great with all of the LEDs running as well. We can't wait to shove a strip of RGB leds in there too.
RaspberryFarm 13 Jan 2016, 3:48 a.m. EST
Day 3 summary: Finished the case, it works very well and the racks slide in nice and smoothly. We attached the raspberry pi model b's to the racks, 2 per rack. Since we only had 7 of them with FTDI drivers, we're leaving one of the racks unpopulated for now. After spending much longer than we probably should have on it, we discovered why we couldn't see the raspberry pis in /dev (didn't press enter). With that, we knew our software infrastructure was mostly done.
RaspberryFarm 13 Jan 2016, 3:51 a.m. EST
Day 3 summary continued: After figuring out the software, we thought about how to power the raspberry pis. Our original design assumed a power of 170mA per device, which is what the zeros draw. These raspis will draw significantly more current, so we have to revise our design to power each of the usb hubs. To interface them with our power supply we needed to get wires out of each of the hubs, so I spent a while taking one apart and fixing it.
RaspberryFarm 13 Jan 2016, 3:52 a.m. EST
Day 3 final: We should be ready to finish the electrical tomorrow. We can plug everything into the power supply, maybe with a breadboard as well for the many different wires we're going to need to supply.
RaspberryFarm 13 Jan 2016, 10:30 a.m. EST
We will be in hamerschlag from 5:00 or so onward
RaspberryFarm 13 Jan 2016, 5:30 p.m. EST
We're in hamerschlag hall now. Hopefully we can get this electrical business sorted out quickly so we can move to writing software!
RaspberryFarm 13 Jan 2016, 9:36 p.m. EST
The whole system works! We didn't blow up the world, or any computers, so that's good ...
RaspberryFarm 13 Jan 2016, 9:57 p.m. EST
Working on writing some software to try to log into all of them without crashing.
RaspberryFarm 14 Jan 2016, 2:47 a.m. EST
We can send files from the master node to any of the other nodes now! It's a miracle! Tomorrow I'll rewrite the system in C to avoid the probably significant overhead of using python as just a command line utility. After that, we need to figure out how to get output back from the nodes, and we can start looking at a final demo.
RaspberryFarm 14 Jan 2016, 5:06 p.m. EST
Cutting the last two racks now!
RaspberryFarm 14 Jan 2016, 8:46 p.m. EST
Raspis are browning out. We think it's because the last hub is being back powered and overloading the regulator ...
RaspberryFarm 15 Jan 2016, 5:58 p.m. EST
Reid Long is exaggerating and is severely underrepresenting the amount of work he did.
RaspberryFarm 15 Jan 2016, 6:01 p.m. EST
Working on getting a demo working. Since so many people thought we were doing a bitcoin machine, that's what we ended up doing (though it's not connected to the internet, so it can't actually mine bitcoins).
RaspberryFarm 15 Jan 2016, 6:07 p.m. EST
Finally got the demo working! We ran out of time and didn't get all of the dependencies working on the raspi master, so we're running it off of my laptop for the demonstration. For some reason the login script doesn't quite work, it might have something to do with the proper screen dependencies not being on there. In any case, it works on my laptop and makes for a pretty solid demo.
RaspberryFarm 15 Jan 2016, 6:11 p.m. EST
MinesweepAR 09 Dec 2016, 8:59 p.m. EST
Reid Long and I spent some time today figuring out the cut list and wood that we'd need to get. Turns out we're just under budget!
MinesweepAR 15 Jan 2017, 9:24 p.m. EST
First day of build is well underway! Just finished one platform, 8 more to go. Unfortunately, our drills are starting to run out of battery :(
MinesweepAR 16 Jan 2017, 12:23 p.m. EST
Team is all together and working hard! Half way done with cutting the squares, its going a lot faster now
MinesweepAR 16 Jan 2017, 5:49 p.m. EST
Starting to work on the buttons! Making good progress, but could use a bunch of extra hands.
MinesweepAR 19 Jan 2017, 2:35 a.m. EST
Done with day 3! We're making good progress, but couldn't have done it without the help of our friends Connor Willison and Shubhangi Bhotika. We're going to start laying out and testing the final circuit tomorrow around 5 in roboclub, please come help if you can!
MinesweepAR 20 Jan 2017, 4:35 a.m. EST
A quick thanks to the sponsors from Key Tech for helping us out with the wiring tonight!