A Q&A With Amplio's Senior Software Design Engineer
The Amplio Talking Book 2 is ready to go! The new device features a rechargeable battery for greater sustainability. Amplio’s senior software design engineer, Bill Evans, shared his insights on digital development, the benefits of a Cortex-M4 processor, and more. Parts of this interview were previously published in a blog post in 2020.
Bill, first, tell us about Amplio’s design philosophy.
Right from the start, Amplio has followed best practices that now have been identified as Principles for Digital Development. Our technology is open source and designed with and for the end-users. All of Amplio’s technology is built with consideration for use cases in developing countries, for online and offline contexts, with or without electricity.
The Talking Book was selected by the UNESCO Pearson Initiative for Literacy as a case study and helped inform UNESCO’s guidelines for digital inclusion.
What’s new with Talking Book 2?
Fundamentally, we did two things: added a rechargeable battery and switched to an Arm Cortex-M4 processor. Rechargeable batteries will help our partners reduce cost and waste, making Talking Book programs more sustainable. Besides that, the new device is a hardware generation or two more powerful than the previous Talking Book.
We're not taking advantage of that new power yet, but we will. One of the new features we're considering is encrypting user feedback.
Why add a rechargeable battery now?
The Talking Book was designed to run on locally-available AA and D batteries—the same batteries that people were already using in their radios and flashlights (torches). As cell phones have trickled into remote, rural areas, it has become more and more possible to recharge devices. With Talking Book 2, people have the option to use the rechargeable battery or stick with AA or D batteries for areas where recharging isn't an option.
What role does Arm support play?
For 10 years, Arm has generously provided Amplio with a broad range of support. This has included employee donations and volunteer hours, free access to Arm's software development tools, and financial support for R&D, marketing, and expansion from one country to 13 countries, including specific projects in Ghana and Zambia.
Tell us about storage capacity.
The Talking Book 2 can store up to 60 hours of audio content. The storage will no longer be a memory card, which can be removed; instead, it's a built-in flash memory.
This is far more storage than what most projects need. For example, if you had six playlists, each with 10 messages, with each message lasting 15 minutes, you would only use 15 hours of storage. So, with Talking Book 2, there's enough storage that you could have multiple languages with all this content on a single device. However, if your project doesn’t need all that storage, you'll get even better audio quality.
There's a sweet spot for how much content to load onto a Talking Book. In general, we find that two to three hours of audio content is about the right amount of information for people to easily navigate and absorb.
Why is storage capacity important?
Storage capacity is directly related to how much content the Talking Book can hold, including user feedback—the messages that community members record directly onto Talking Books, which can be hundreds or thousands of messages on a device. We don't need an enormous capacity, because most of our partners update their Talking Book content every few months when they go to the field to collect usage data and user feedback. But we don't want the storage capacity to ever be the limiting factor.
What were some of the design challenges?
Because time passed, and some components became obsolete, we had to do an entirely new design. This means we ran into issues with things like the clock speeds and startup sequences of codecs, storage, and other peripherals.
In the midst of the COVID-19 pandemic, the factory that manufactured one of the chips in our design burned down, and that chip became unavailable overnight. We had to find a new chip, from a different manufacturer, and redesign the circuit to accommodate it. Then we had to rework the software to use the new chip. And of course, we had chosen the first chip because we thought it was better and easier to work with.
Like everyone, we've been impacted by the global supply chain disruption.
A high-level block diagram of the Amplio Talking Book 2.
Sounds like quite a challenge!
Yes, and that isn’t the only challenge. Amplio is a small organization and the Talking Book is intended for people living in extreme poverty. This means we don’t have a big design budget, so it’s a challenge to come up with a low-cost, low-power, flexible design without spending thousands of dollars of engineering time. We need to build an easy-to-use, innovative device that’s cheap to manufacture.
Keeping the price down helps our partners reach more people.
Why are you switching to the Cortex-M4?
The Cortex-M4 will enable features that were out of reach before. The True Random Number Generator (TRNG) and computing power will let us improve data security. Specifically, we can provide state-of-the-art encryption of user feedback. Previously, Talking Book messages were mostly about farming and livestock. Now our partners are using the device to address sensitive topics like gender equality and land rights, so there’s a need for us to be able to collect information and keep it private.
Multilingual Talking Books chatter during a Talking Book 2 battery charging test.
Where is the Talking Book 2 being used — and how can someone get one?
Earlier this year, we field-tested Talking Book 2 with partners in Ghana. Now FAO Uganda is about to deploy 400 Talking Books to support women's land rights in the West Nile region — and about half of their devices will be Talking Book 2. Some communities still don't have the ability to recharge devices, so they can use regular batteries.
If folks are interested in Amplio Talking Book 2, they can contact us here.
What’s next for the Amplio product team?
This past year, we released a new system for processing user feedback. We updated the dashboard so that our partners can interact with Tableau-based data visualizations. (You can try out our training dashboard here.) We're working to enhance the Amplio Suite, a web-based set of program management tools to support our partners.