iBeacons and the Monticello App
An interview with Developer Paul Rudolph on the use of iBeacons for the Monticello App.
Working with The Thomas Jefferson Foundation we built the app, Slavery at Monticello: Life and Work on Mulberry Row, that tells the stories of the people who lived and worked at the industrial hub of Thomas Jefferson’s agricultural enterprise. Utilizing iBeacons and geo-location technology, we hope to provide a compelling experience for visitors when they explore the physical sites at Monticello’s Mulberry Row.
We’ve interviewed our developer Paul Rudolph to hear some of his challenges and experience using iBeacons for this project.
First, what are beacons?
Beacons are small devices that emit a unique Bluetooth signal. Beacons can be placed on objects or affixed to specific locations to help give location context to mobile applications. Mobile applications that are listening for these signals can determine if a user has walked near a particular beacon and present relevant information. One common example is the application of beacons in retail space. Beacons can be set to advertise generally for a store front, triggering an alert to a passerby enticing them to enter the store. Additionally, beacons can be set to a specific area within the store and trigger alerts on items that the user is standing next to. While retail campaigns do not always fit in the museum setting, the core ideas can be modified to work well in an educational setting attracting visitors to learn more and make a deeper connection with the presented content.
While beacons can be used to help determine a user’s proximity to an object or location, it is very different from traditional GPS location that uses satellites. GPS location requires an unobstructed view of the sky to receive signals from satellites to determine a location on a map. Location based on beacon signals do not require a view of the sky making them better suited for indoor use. The trade off with using beacons for location is that their signals do not necessarily relate to a specific point on a map, so it becomes much more difficult to pinpoint a user’s location.
Most beacons have adjustable broadcast settings, which gives the ability to control how far away the beacon signal can be detected. On the highest broadcast power setting some beacon distances can reach about 230 feet. Beacons also have an adjustable broadcast interval which controls how often a signal is emitted. When beacons are placed in a busy area a shorter interval is needed for listening applications to distinguish the signal from interfering radio noise. Since beacons consume very little power, they generally use small batteries that can last from several months to a few years. Overall the power settings that are used will directly affect how long the beacon’s power supply will last.
What was the inspiration to use beacons for this project?
One of the goals of the Monticello application was to be able to allow users to learn about the physical objects and locations on Mulberry Row. We wanted the application to encourage the user to explore more content when they approached tagged locations or objects. The grounds of Monticello proposed a challenge for using traditional GPS geo fencing since some of the locations are as close as 10 meters to each other and we would not be able to determine which location the user was actually near. The application also had to allow for more outdoor and even some indoor locations to be added through a CMS in the future. Beacons quickly became the clear choice as they could handle smaller regions more accurately and would work the same way indoors and outside.
We also explored the option using a WiFi network for micro location. While WiFi could be used to provide the location services throughout the grounds, we found this would require the implementation of several wireless access points. The hardware installation could be potentially damaging to historic buildings and overall was a more costly solution.
Why did you go with the beacons you chose?
After testing and researching many brands of iBeacons, we decided to use with Gelo beacons. We found that the waterproof casing was most suited for outdoor use and allowed for easy replacement of the batteries. The casing also afforded us the ability to use normal screws to mount the beacons to the buildings and objects on the row. The structures on Mulberry Row varied in the types of materials, which made using adhesives a poor choice for long term placement.
Gelo beacons offered an interesting solution for configuring each beacon. Equipped with the companion mobile application and a magnet we could quickly make changes to each device. By swiping a magnet across the face of a beacon, you can trigger a configuration mode in the mobile application which makes on-the-fly adjustments easy. This method was much less time consuming during the initial testing phase when we were testing many different configurations.
Initially, we were working with Estimote beacons. While the performance as an iBeacon was fine there were several reasons why we decided to use a different brand. The most glaring issue was the fact that Estimote beacons are not waterproof. The casing is made of silicone which conversely makes the only way to replace the battery cutting them open. Many beacon companies advertise a lifetime of several years, however we found that the actual battery life is much shorter in a real world context. Using Estimotes would require reskinning the beacon every time you replace the batteries.
Placement of the beacons required a lot of consideration. They needed to be out of sight or blend in with the structure. There is also the potential for large crowds which forced us to place the beacons up high so groups of people would not block the signal. We needed to be able to adjust the positions throughout the seasons as we gathered more information on how the application responded to the signals. The Estimotes used an adhesive for mounting which would limit how many times they could be attached to a surface. Additionally, the colorful silicone casings conflicted with the need for the beacon to blend in with the environment.
How has the process been in working with these beacons?
Working with beacons has been an interesting endeavor. Applications do not always respond as you would expect. Sometimes devices would seem to completely ignore the signal, while other times the application would trigger several times while standing near a beacon. Differences in different phone model hardware, interference from the environment, and close beacon proximity all proposed several challenges.
For example, during initial testing we found that the iPhone 4s was picking up on beacon signals much further away than intended and much earlier than newer devices like the iPhone 5 , 5s and 6. As we would approach a beacon, the 4s would trigger an alert, lose the signal, then present a new alert once it got closer. We used a technique to limit how frequently the user would be alerted, making sure the user would not be bombarded by alerts. We also limited the application to only show one alert per location for a session to help prevent alerts from bouncing back and forth from overlapping signals.
Since there are so many different models and brands of Android devices with varying Bluetooth LE hardware, an effort was made to find a happy medium between iOS devices and different Android devices.
Beacon signals are greatly affected by surrounding materials. Water has a large impact on the signal strength which means people standing in front of the beacon can greatly reduce the signal range. During initial testing we found we could trigger an enter and exit notification just by hiding a beacon behind our backs.
We followed the advice from other teams to position the beacons as high as possible rather than at eye level to help cut down on interference. When there was no structure that would allow for high placement we looked for nearby trees for placement opportunities.
How did iBeacons help us solve the challenge of telling this story?
The beacons gave us the ability to relate all the content to a specific location on Mulberry row. Visitors can make a much deeper connection with the content they are looking at and stories they are hearing when they are standing in the physical locations being referenced.
The app also features comments and narration by descendants of Monticello’s enslaved community, archival photos and audio clips and subtle game-like feedback loops to let visitors know what locations they’ve visited.