.Communication-Protocol-Quick-Start-v1.0

Customer Documentation: Neonode® Touch Sensor Module User's Guide : .Communication Protocol Quick Start v1.0

Encoding Integers

ASN.1 encoded integers, for example values representing scanning frequency or touch active area size, are represented by one or more bytes:

If the integer is between 0 and 127, it is represented by one byte (00 to 7F).
If the integer is between 128 and 32767, it is represented by two bytes (00 80 to 7F FF).

The length of the message therefore varies depending on parameter values.

Enabling Sensors

Do the following to enable a sensor, that is, tell a sensor to start sending touch notifications.

Enable the sensor by sending a request with an Enable command:
```
EE 09 40 02 02 00 65 03 81 01 00
```
This enables the sensor to send touch notifications.
Read the response. The response should be:
```
EF 09 40 02 02 00 65 03 81 01 00
```
After this, wait for the sensor to indicate it has something to send, which means that the device will send a Touch Notification or a BootComplete. A BootComplete indicates that the device has restarted for some reason, so rerun the initialization and enable the sensor to start receiving touch notifications again.

Disabling Sensors

Do the following to disable a sensor, that is, tell a sensor to stop sending touch notifications.

Disable the sensor by sending a request with the following command:
```
EE 08 40 02 02 00 65 02 80 00
```
This disables the sensor to send touch notifications.
Read the response. The response should be:
```
EF 08 40 02 02 00 65 02 80 00
```

Device Configuration

Device configuration is a command that includes different settings for the sensor, for example the Touch Active Area. When sending a device configuration message, all of the settings specified are not required to be sent, however the response from the sensor will include the full device configuration message.

This is an example message that changes the touch active area using the Device Configuration command:

EE 1A 40 02 02 00 73 14 A2 12 80 02 00 B5 81 01 43 82 02 06 98 83 02 04 34 85 01 FF

The message is explained in the table below:

Part	Description
`EE 1A`	ID for request followed by length of total payload (0x1A = 26 bytes)
`40 02 02 00`	Device address (always the same for the zForce AIR Touch Sensor)
`73 14`	ID for Device Configuration followed by the length of the total Device Configuration payload (20 bytes)
`A2 12`	ID for Sub Touch Active Area followed by the length of Sub Touch Active Area payload
`80 02 00 B5`	ID for xMin followed by payload length and an integer value (0x00B5 = 181)
`81 01 43`	ID for yMin followed by payload length and an integer value (0x43 = 67)
`82 02 06 98`	ID for xMax followed by payload length and an integer value (0x0698 = 1688)
`83 02 04 34`	ID for yMax followed by payload length and an integer value (0x0434 = 1076)
`85 01 FF`	ID for "Invert y axis" followed by length of payload and a Boolean (0xFF= True)

The response from the sensor to the above message will contain the full device configuration message, also the parts not set in the request.

Setting the Touch Active Area should be done before enabling the sensor with the ENABLE request.

Setting Frequency

To set the finger frequency to 200 Hz and idle frequency to 63 Hz use a request with the following command:

EE 0D 40 02 00 00 68 07 80 02 00 C8 82 01 3F

The zForce AIR Touch Sensor does not support Stylus mode, and setting the stylus frequency does not do anything.

Decoding Touch Notifications

A packet can contain one, two or three Touches, and optionally a timestamp. On packets where the timestamp is not included, the 58 02 TT TT bytes are missing from the end and the length bytes are adjusted accordingly, For One touch (below), F0 15 in the beginning will be F0 11 and A0 0F in the middle will be A0 0B. The same bytes are decreased by 4 for Two and Three touches.

One Touch

A packet that contains one touch will look like:

F0 15 40 02 02 00 A0 0F 42 09 II VV XX XX YY YY GG HH JJ 58 02 TT TT

where the data is defined as follows:

Syntax	Meaning
II	ID of this specific touch object. More than one can be tracked simultaneously.
VV	Event: 00 = DOWN (new object). 01 = MOVE (existing object has moved). 02 = UP (existing object is no longer being tracked).
XX XX	X Coordinate of the object. This is in Network Byte Order / Big Endian / Motorola Endian.
YY YY	Y Coordinate of the object. See above.
GG	Size of object on the X Axis.
HH	Size of object on the Y Axis.
JJ	This value must be ignored.
TT TT	Timestamp of the touch.

Two Touches

A packet that contains two Touches will look like:

F0 20 40 02 02 00 A0 1A 42 09 II VV XX XX YY YY GG HH JJ 42 09 II VV XX XX YY YY GG HH JJ 58 02 TT TT

where the first "II" and the following bytes up to and including "JJ" are from the first touch, and the second "II" and the following bytes up to and including "JJ" are from the second touch.

Three Touches

A packet that contains three Touches will look like:

F0 2B 40 02 02 00 A0 25 42 09 II VV XX XX YY YY GG HH JJ 42 09 II VV XX XX YY YY GG HH JJ 42 09 II VV XX XX YY YY GG HH JJ 58 02 TT TT

Document generated by Confluence on Sep 11, 2025 11:01

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