Intel Galileo e-Ink Reader
The idea started with a very casual conversation with one of my colleague on how e-Ink readers worked, and when we received the Galileo – our first project was born. Getting an e-Ink display mated with Galileo.
Display : Pervasive Display (10.2”) active matrix display, 160dpi – capable of displaying fine prints and fonts. (PervasiveDisplay)
Board : Galileo
Operating System : Linux (Yocto Distribution)
Other Software : ImageMagick to convert PDF to grey scale images. (the quality still can be improved)
The Road to Finish.
- First we developed the e-Ink display software in Windows and verified that we were able to display predictably the images on the e-Ink display. This provided a good platform for us to debug and for any issues we could fall back on Windows debugging to get the images right. The software will take an image (grey scale bitmap) and display it on the e-Ink display.
- Then we ported the software stack to Ubuntu 12.04 and got it working. Now we have both windows and Linux version available.
- Setting up the Galileo
- Since Galileo can run Linux, our obvious choice was to run this software from SD-card using Yocto Linux. Running Linux on Galileo is a great advantage.
- We faced a lot of hiccups in compiling the Full Yocto Linux distribution for Galileo, especially with node-js package not getting compiled. It took a while to get it fixed. The Yocto Linux compilation takes a while to get compiled.
- To get connected with Galileo, there are a couple of options. One is to use SSH if the image is minimal or you can use USB to Serial cable (custom built 3.5 mm to USB). With this we were able to establish a TTY connection.
- To connect the e-Ink display, we used the USB host port. The challenge here was to get the correct drivers for communication between e-Ink and Galileo.we used the cdc-acm driver which is part of Yocto, we got it compiled and able to load the same. This provided us a virtual serial port (/dev/ttyACM0). This port helped us to send serial commands and data over USB.
- Once the setup is established we were able to flash the image using our software stack.
- Currently we are using standard B/W bitmaps to display. To be a true e-Ink reader it needs to take a PDF and display. For this, we got hold of ImageMagiK and used their sources to convert PDF to BMP. We can add a couple of buttons for PREV, NEXT and HOME using GPIO and it will be a full-fledged e-ink reader. Currently the GPIO work is pending.
Detailed documentation on enabling e-Ink reader is attached.
It’s a great feeling to get this done and having an e-Ink reader built - we had learnt a trick or two.
Cheers
Sriram , Maharshi and Munish