After the successful completion of Erica’s upgrade, she has been at the Big Bang Fair in Birmingham representing the University of Southampton for the last two days and will be there again today and tomorrow. She has already meet thousands of kids over the first two days and hopes to make more friends over the remaining two days.
Erica making some new friends (courtesy: @UoS_Roadshow from twitter.com)
Reena has being writing about Erica and the Big Bang Fair in recent posts on her blog. If you want to read in more detail what Erica has been up to.
Erica will be making her way back from Birmingham on Sunday night and will have a short break before appearing at the Science and Engineering Day at the University on Saturday 22nd March.
As we have been so busy working on Erica’s we haven’t had a chance to report back on the results. Stand by over the next few weeks to get a more detailed insight into the Erica modifications and how she is even more interactive than she was before.
Erica’s original system was based around the TLC5940 LED driver chip which was controlled directly by the mech pi with an ATtiny45 on the pi daughter board to provide the clock signals.
Erica old LED setup
For those that came to visit Erica in person you will have noted that the LEDs were not always working. Although we haven’t been able to work out the exact cause of the issue we believe it may be due to the chips either overheating (ambient temperatures inside Erica got up to 58C when in the Marlands), or due to large voltages being inducted onto the signal wires linking the drivers.
To resolve these issues we have created a new LED controller design for Erica. The following are the major improvements over the previous version:
- As we wanted to avoid replacing or altering the leds we had already installed the new controller is designed to connect up to the connectors on the existing LEDs.
- The new board uses the same driver chip (TLC5940) as the previous version but is instead controlled by an atmega168 (used on some arduinos) located next to the led driver.
- In order to improve the signalling between the boards the new design uses the DMX512 protocol, this is often used in event or architectural lighting setups
- Cat5 cables (commonly used for computer networks) will be used to connect the boards together as they are easily available and easier to work with than the original ribbon cable connections
- Internal debugging LEDs to help with healing Erica when she is unwell.
- Socketed chips to allow replacement if things go wrong
Below you can see the new controller design being tested. The controller itself is on the white breadboard, the blue breadboard is the transmitter that will put on the mech pi daughter-board. The cat5 cable connecting the two boards for this test is over 30m long so it shouldn’t have any trouble with the distances inside Erica
Erica new LED controler test
Rather than build these controllers on strip-board we have designed a custom PCB (Printed Circuit Board)
Design For Erica’s new LED controler
The boards will take a couple of weeks to be manufactured and shipped to the UK, when they arrive we will show you the new setup in action.
One of Erica’s first excursions after her return to ECS, will be to the Big Bang Fair in Birmingham from the 13th to 16th of March. Before then, there are some significant upgrades planned to make Erica a more robust and even more interactive cyber rhino. These include:
- Panels of connectors on Erica’s plinth so she can more easily be disconnected and reconnected when she is taken on excursions. These connectors will also help diagnose problems if Erica gets ill and will provide the means to interact with her in new ways.
- Android touchscreens so replace the display panels in Erica’s body so people can interact with Erica and the information about here rather than just viewing static pages.
- A revamp to the Erica’s LED system, so it is more resilient to heat and electromagnetic interference. When Erica originally arrived in the Marlands shopping centre, none of us could have known how hot it was going to be last Summer.
- An separate touchscreen display that allows people to see what Erica sees and control her eyes, ears, sounds and LEDs.
Over the next few weeks, leading up to the Big Bang Fair, other team members will post updates on the progress they have made with these upgrades but for now here is a sneak peak on the work to revamp Erica’s LED system.
Erica is made up of many parts, allowing her to interact with her environment and the people who visit her, as well as being continually connected to the Internet. If you click on the diagram below you can take an interactive tour of the components that make up Erica.
Interactive Diagram of Erica’s Components
- 32 LEDs
- 19 bespokely built cirtcuit boards
- 15 Red-Green-Blue (RGB) LEDs
- 8 sensors
- 5 raspberry Pis
- 4 power supplies
- 2 LCD screens
- 2 ethernet switches
- 2 servo motors
- 2 stepper motors
- 2 stepper motor controllers
- 2 cameras
- 2 Wi-Fi dongles
- a bluetooth dongle
- a speaker
- a real-time clock
- a USB hub
- and a kill switch.
This is my new home in the Marlands Shopping centre with some of my school-Rhino friends! I have already met lots of people on the first day! Over the next week I will be learning new skills (like how to send more Tweets ).
The Go! Rhinos website has launched the free trail map which shows you where all 36 rhinos will be placed through Southampton.
Download the Go! Rhinos free trail map!
Go check it out, so you can follow the trail and visit Erica on the way (she’s number 17 on the map, in case you were wondering) 🙂
See where Erica and her cousins will be located in Southampton this summer!
A new clip appeared in the Times higher education newspaper today
Erica the Rhino news clip in THES – showing Graeme Bragg and Kirk Martinez working on the electronics