Bump for a Beer
I was excited to receive a summer internship offer from Bump because they’re working to solve a really interesting problem: How can we enable any two devices in the world to communicate with each other, regardless of the operating system, peripherals, and existing communication protocols installed?
I’m from Sacramento, California, and this fall I’ll be a senior in Electrical Engineering at the University of Pennsylvania. I can’t say too much about what I’m working on at Bump, but I can say that I’m working to make Bump work with other devices besides smart phones. :)
Speaking of bumpable devices, on my second day of work, Will Moss asked me for some help finishing the Bump hackathon project he worked on with Jamie Turner and Jake Mintz. Their project was a bumpable kegerator, or “The Bumperator” for short. The idea is that you bump with a kegerator using the Bump app, and it dispenses a perfect glass of beer with just the right amount of head. A website tracks the users with the most glasses of beer consumed, and users can even get updates from the kegerator by messaging it using the Bump app. The particular problem Will asked me about was how to dispense the beer from the kegerator. He had already purchased a solenoid valve that is closed by default and opens when you give it 5V, but unfortunately the controller board we were using can only output 1.8V. Another issue is that the solenoid valve draws almost 0.5A, and our controller board can’t source that much current. Ironically, getting our controller board to communicate with the solenoid valve is a lot like the problem I mentioned Bump is trying to solve. Only there’s no Bump app for electric signals (yet?). Luckily there are several ways to connect devices of different voltage levels. It’s even simpler when the communication is one-way, like in this scenario. One solution would be to use a transistor amplifier to amplify the 1.8V signal to 5V. Will had already tried this before, using a high power transistor he had purchased at Fry’s. He wasn’t able to get it to work, so we kept brainstorming. There were two other considerations as well: time and resources. Bump was having its Magic Show in a few days followed by an open house at the new office, and the goal was to have the Bumperator operational in time. So we were sort of limited to using parts we could buy at electronics stores nearby. We ended up going with an LM324 (single-supply op-amp) in comparator mode connected to a reed relay. The controller board’s GPIO pin conencts to the comparator, which switches between the 5V of the controller board and ground, but the controller board’s 5V supply can’t source the 0.5A the solenoid valve requires. So the output of the comparator triggers a reed relay which can switch an external 5V DC power supply. (See photos for the schematic I drew)
This circuit works pretty well, as our Magic Show guests discovered at our open house. It felt great to see so many people using and enjoying something I had helped to create. I think that’s what I enjoy best about working at Bump. The product I help create will be used immediately, whether it's by few hundred people at a recruiting event, or by several millions of people through the actual app. That really means a lot to me.
I’m from Sacramento, California, and this fall I’ll be a senior in Electrical Engineering at the University of Pennsylvania. I can’t say too much about what I’m working on at Bump, but I can say that I’m working to make Bump work with other devices besides smart phones. :)
Speaking of bumpable devices, on my second day of work, Will Moss asked me for some help finishing the Bump hackathon project he worked on with Jamie Turner and Jake Mintz. Their project was a bumpable kegerator, or “The Bumperator” for short. The idea is that you bump with a kegerator using the Bump app, and it dispenses a perfect glass of beer with just the right amount of head. A website tracks the users with the most glasses of beer consumed, and users can even get updates from the kegerator by messaging it using the Bump app. The particular problem Will asked me about was how to dispense the beer from the kegerator. He had already purchased a solenoid valve that is closed by default and opens when you give it 5V, but unfortunately the controller board we were using can only output 1.8V. Another issue is that the solenoid valve draws almost 0.5A, and our controller board can’t source that much current. Ironically, getting our controller board to communicate with the solenoid valve is a lot like the problem I mentioned Bump is trying to solve. Only there’s no Bump app for electric signals (yet?). Luckily there are several ways to connect devices of different voltage levels. It’s even simpler when the communication is one-way, like in this scenario. One solution would be to use a transistor amplifier to amplify the 1.8V signal to 5V. Will had already tried this before, using a high power transistor he had purchased at Fry’s. He wasn’t able to get it to work, so we kept brainstorming. There were two other considerations as well: time and resources. Bump was having its Magic Show in a few days followed by an open house at the new office, and the goal was to have the Bumperator operational in time. So we were sort of limited to using parts we could buy at electronics stores nearby. We ended up going with an LM324 (single-supply op-amp) in comparator mode connected to a reed relay. The controller board’s GPIO pin conencts to the comparator, which switches between the 5V of the controller board and ground, but the controller board’s 5V supply can’t source the 0.5A the solenoid valve requires. So the output of the comparator triggers a reed relay which can switch an external 5V DC power supply. (See photos for the schematic I drew)
This circuit works pretty well, as our Magic Show guests discovered at our open house. It felt great to see so many people using and enjoying something I had helped to create. I think that’s what I enjoy best about working at Bump. The product I help create will be used immediately, whether it's by few hundred people at a recruiting event, or by several millions of people through the actual app. That really means a lot to me.
- Kevin
