Live Pen™ 2 - MMI Implementation


The display is divided into one icon area and one identity area. The icons represent status of Battery, Memory consumption and Bluetooth activity.

Icon area

The icons below can appear in the icon area (note that the memory/pen and battery fill icons have more fill levels, these are just examples). 

Bluetooth status

Bluetooth status Icon
Turned off 'flight mode' icon
Pairing 'Bluetooth' flashing 0.5/0.5 s
Connecting 'Bluetooth' flashing 0.5/0.5 s
Connected 'Bluetooth' steady
Disconnected, but stack on No icon

Battery status

Battery level Icon Vibrator
0 ("critical") No battery icon  
0 - 4% ("warning") Empty battery, flashing 0.5/0.5 s Error buzz
5 - 10 % 10% filled (height: one pixel)  
11 - 20 % 20% filled (height: two pixels)  
21 - 30 % 30% filled (height: three pixels)  
31 - 40 % 40% filled (height: four pixels)  
41 - 50 % 50% filled (height: five pixels)  
51 - 60 % 60% filled (height: six pixels)  
61 - 70 % 70% filled (height: seven pixels)  
71 - 80 % 80% filled (height: eight pixels)  
81 - 90 % 90% filled (height: nine pixels)  
91 - 100 % 100% filled (height: ten pixels)  
Charging, normal Battery with "spark"  
Charging, when battery level <= 4%  Flashing battery with "spark"  

Memory status

Memory level Icon
0 % empty
1 - 10 % 20% filled (height: two pixels)
11 - 20 % 30% filled (height: three pixels)
21 - 30 % 40% filled (height: four pixels)
31 - 40 % 50% filled (height: five pixels)
41 - 50 % 60% filled (height: six pixels)
51 - 60 % 70% filled (height: seven pixels)
61 - 70 % 80% filled (height: eight pixels)
71 - 80 % 90% filled (height: nine pixels)
81 - 99 % 100% filled (height: ten pixels)
100 % "Memory inactive" icon (full pen with stroke across), flashing 0.5/0.5 s
Memory locked (when sending) "Memory inactive" icon (full pen with stroke across)
Writing on Anoto paper when memory locked "Memory inactive" icon (full pen with stroke across), flashing 0.5/0.5 s
Writing on non-Anoto paper "Memory inactive" icon (full pen with stroke across), flashing 0.5/0.5 s
Writing with encryption enabled or on paper requiring encryption "Padlock" icon alternating with any of the above icons.

When the pen is docked, pen down is inhibited to prevent accidental modification of stroke storage while connected over USB.

Identity area

This area is set from host. If not set, then a default bitmap is used:


The vibrator gives three types of vibrations, defined in the table below.

If the user handle the pen so many vibrating events are made (e.g. repeated pen down on non anoto paper), the vibrating time may be integrated.

Vibration type Vibration length Occasion (if not covered in flowchart)
Confirmation 50 milliseconds  
Negative feedback 500 milliseconds  
Error 1300 milliseconds
  • Battery level below 5% ("battery warning").
  • Battery voltage below 3400 mV ("battery critical")
  • Memory full
  • Writing on non-Anoto paper

Note that the vibrator is muted when the pen is docked, and in the case of battery warning/critical will 'sound' when the pen is undocked.


Display, general

While the pen is connected to USB, it always displays both areas. To prevent burn-in damage from causing permanent loss of intensity, the display will repeatedly fade in and out and stay black for two seconds at a time while the pen is docked. For user to be fully aware that the pen has been docked, all pixels in the display are lit for two seconds before starting the 'screen saver'.

When disconnected it displays the entire display for 5 seconds, and then only the icons for 5 more seconds.

When disconnected and idle the display is off. 

The ID area is shown for five seconds after the pen is touched. If the pen is held without activating the touch sensor, pen down causes the ID display to light up, but only if the display is off at the time (to avoid making the ID field light up for each pen down).

The icon area stays lit as long as the pen is being held (or pen tip is down). After releasing touch sensor and pen tip is up, the icon area stays lit for 10 seconds. 

Non-Anoto paper

When putting the pen tip to non-Anoto paper it gives negative feedback through the vibrator and by displaying the NAP (Non-Anoto Paper) memory icon. Continuous writing on such paper does not result in repeated negative vibrations, but the NAP icon keeps blinking. If the pen has been up for ten seconds, the NAP negative buzz will appear again. Writing on Anoto paper will also reinstate that warning. 

A very short pen down on non-Anoto paper will not give negative feedback in order to avoid negative buzz on accidental pen down.

MMI flowcharts

This flowchart gives a more complete picture of what happens when different frames arrive, e.g. pidget enter/exit, non-Anoto paper, etc., and what MMI changes they cause.

Download picture

This flowchart describes the Bluetooth connect procedure, how a connect command (i.e. pidget enter) is handled in the different states, and what MMI effects it has. A second flowchart is included that describes the parts of the APE communication over Bluetooth that is relevant for this purpose.

Download picture

Download picture

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