EE460 Reverse Engineering
The i>clicker is classroom voting system that allows many students to submit answers to a computerized system, which instructors can use to evaluate student understanding of material and perform in-class quizzes. The i>clicker remote is a 6-button device with 3 LEDs to display power, battery, and vote status to the user, a 900MHz ISM band transceiver for submitting and receiving votes/status. It runs on 3 AAA batteries, measures 6" x 2" x 0.5", and weighs 3 ounces. It can be purchased from online retailers or in stores for approximately $35.
Teardown/Disassembly Procedure
- Step 1:
- Remove the batteries and battery door
- Step 2:
- Remove the three screws holding the case together
- Step 3:
- Lift battery connectors out from case
- Lift PCB out from case
- Step 4:
- Remove two screws holding the PCB to the chassis
- Pop out the tab holding the LCD to the PCB
Improvements
Our group had a discussion on possible improvements to the device according to the SCAMPER method, which provides a list of ways that a product could improve.
- Substitute: Decrease time to sleep, decrease LED brightness (substitute higher resistor values)
- Combine: Combine microcontroller and transceiver, example ICs: TI's CC1110F8, which combines a comparable microcontroller and transceiver IC on a single chip at a lower price point (per 1k units)
- Adapt: Dual use as a Powerpoint or presentation slide controller
- Modify: Change LED color
- Put to other uses: Add a question asking queue
- Eliminate: Make the device shorter and thinner to conserve material and lower costs
- Rearrange or Reverse: Move LEDs to accomodate the smaller size, use a different antenna, change the number or type of batteries
The following ideas could improve the sustainability of the device:
- Use rechargable batteries
- Use a biodegradable casing or make the device easier to disassemble for recycling
- Add instructions for sustainably disposing of the device
The following ideas could reduce manufacturing costs for the device:
- Remove screws, change design to a snap-together case
- Use a lower volume of plastic in the construction
- Move to a smaller design
IC List
Component | Additional Text | Manufacturer | Function |
---|---|---|---|
XE1203FI063 | UC439026 | Semtech - XE1203F | Single chip 433, 868 and 915 MHz ISM band transceiver. Up to +15dBm Output power and -114dBm sensitivity. |
G3A | Unknown | RF Transmit/Receive switch | |
ATMEGA8L | 8AU 1026G | Atmel - ATmega8(L) | 16MHz 8kB Microcontroller with built in 8-channel A/D and 23 programmable I/O. |
L0RB | Unknown | 3.3V Linear/LDO Regulator | |
39A000 | F0AB | Unknown | 39MHz Crystal Oscillator |
4A000 | F0AB | Unknown | 4MHz Crystal Oscillator |
Additional Photos
- Iclicker-tophalf.jpg
Top half of the i>clicker PCB.
- Iclicker-bottomhalf.jpg
Bottom half of the i>clicker PCB.
- Iclicker-transceiver.jpg
XE1203F Transceiver IC.
- Iclicker-antenna.jpg
915 MHz Inverted F antenna, TX/RX switch, and matching network(s).
- Iclicker-microcontroller.jpg
ATmega8L Microcontroller.
- Iclicker-fast-diagram.png
Functional Analysis System Technique (FAST) diagram for the i>clicker.
- Iclicker-sop-tree.png
Subtract and Operate Procedure (SOP) diagram for the i>clicker.