Chameleon keyboard controller

The Chameleon is a user programmable keyboard controller with a wide range of features.

Description

The Chameleon model CH-20056 is basically a Sprintek SK5102 processor on a breakout board for easy DIY access. Apart from the main processor some resistors, capacitors, an inductor and a buzzer (that's not actually connected to anything) have also been added to the board. The Chameleon comes supplied with a USB Mini-B shield that sits on top of the main board connected through a 4-pin header, this shield is marked as type AB-001A - Oct.01,2011 v1.0 By YJX

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  Chameleon complete top view

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  Chameleon complete side view

Features

• USB 2.0 full speed
• User-Programmable keyboard matrix, scan code and macro keys
• 4 sets of 8 x 20 keyboard matrix for Numlock(or RFN) and FN cases
• N-key rollover support
• Up to 255 Custom/Macro keys: generate “LCTRL+LALT+DEL”, “000” and “Diet Coke”
• Built-in KeyMouse
• AB rotary encoder mapped keys
• Support PS/2 command pass-through via USB port
• Key-controlled and USB-controlled 8 general purpose output(GPO), 1 state control output(SCO), 1 backlight PWM, 1 Alert LED control, Blackout control
• One external hot-plug PS/2 port supports PS/2 keyboard and mouse including wheel mouse
• Support three FN control modes: Level, Toggle and Sticky
• Support two delay keys
• Supports USB selective suspend and remote wakeup
• Built-in oscillator and digital circuit. No external crystal is needed
• Windows® application to design keyboard matrix
• Low profile QFN 56 pin package: 8x8mm 1.0 Max (LxWxH)
• Low power consumption. 230uA (USB suspend) and 18 mA (USB operation)
• 4.57 to 5.25V operating voltage
• Commercial temperature range:0°C to +70°C

Sprintek SK5102

The main processor on the Chameleon is the Sprintek SK5102 (PDF datasheet);

The SK5102 is a USB keyboard and KeyMouse combo encoder with a user-programmable keyboard matrix. The IC can be programmed to any keyboard with four matrix tables for FN and NUMLOCK(or RFN) cases, so the IC is the best choice for custom keyboard solution but with an off-the-shelf IC. The SK5102 scans and encodes an 8-row by 20-column matrix. The key press events are translated to keyboard and mouse report. The encoder gets matrix information from on-chip flash matrix table. Sprintek provides Windows® application FlexMatrix Editor and Programmer software to edit, download and upload the matrix table. The SK5102 scans AB rotary encoder inputs then map the rotation events to two key locations in the key matrix. The SK5102 provides an external PS/2 port that supports hot plug and hot swap of PS/2 mouse including wheel mouse, and keyboard devices.

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  Illustration showing the processor orienation

Technical data

'Chameleon-Green' model CH-20056, V1.0 by YJX Oct.01.2011

Dimensions

Chameleon complete (including USB shield), outside dimensions

• Width; 30.0 mm
• Length; 65.0 mm
• Height; 18.0 mm

Main board only

• Width; 21.0 mm
• Length; 56.0 mm
• Height; 7.5 mm
• Soldering islands; 2x28 rows with 2mm spacing

Possible modifications to reduce height;

• Height; 4.8mm after removing the USB Mini-B shield and de-soldering the header for the USB Mini-B shield (requires alternate USB connection to main board)
• Height; 3.3mm after removing the USB Mini-B shield and de-soldering both the header and the buzzer (requires alternate USB connection to main board)

It is also possible to reduce the width by roughly 2mm without losing functionality, this requires mechanically removing the sides of the board and the header pins. Reducing the length is possible but to retain functionality this will require rewiring and some properly anal soldering skills.

Firmware

The CH-20056 comes pre-flashed with firmware version 1.02 Revision 4.

Software and manual

There are various software suites available for programming, editing, testing and demonstrating purposes. These can be downloaded from the Sprintek website here.

The manual that is made available can be downloaded through mediafire here

Chip pinout to board connection table

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  Board top side

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  Board bottom side

Board connector	connection type	IC Pinout	Notes	Description
VS	through 0 inductor	VSS		Ground connection
D+	through 24.4Ohm R	D+		USB D+ line
D-	through 24.4Ohm R	D-		USB D+-line
VB	Direct	VDD		Power supply
PD	Direct	XPS2DAT	also connected to ground via pur	External PS/2 port data line with internal pull-up resistor
PC	Direct	XPS2CLK	also connected to ground via pur	External PS/2 port clock line with internal pull-up resistor
G7	Direct	GP07		GPO pin
G6	Direct	GP06		GPO pin
G5	Direct	GP05	marking unreadable on board	GPO pin
G4	Direct	GP04	marking unreadable on board	GPO pin
G2	Direct	GP02	marking unreadable on board	GPO pin
G0	Direct	GP00	marking unreadable on board	GPO pin
BIN	Direct	GPO3/BIN	marking unreadable on board	GPO3 or AB rotary B input
AIN	Direct	CPO1/AIN	marking unreadable on board	GPO1 or AB rotary A input
PWM	Direct	BKPWM		Backlight brightness control: PWM output
PGC	Direct	PRGCLK		Programming interface clock line
PGD	Direct	PRGDAT		Programming interface data line
GND	Direct	VDD		Power supply
RE1	Direct	RESV		This pin is reserved.
VC	Direct	VSS		Ground connection
LF	3.3kOhm R	nLED_FN		FN LED: direct drive
LK	3.3kOhm R	nLED_KANA		KANA LED: direct drive
LO	3.3kOhm R	nLED_COMP		Composer LED: direct drive
LS	3.3kOhm R	nLED_SCROLL		Scroll lock LED: direct drive
LC	3.3kOhm R	nLED_CAPS		Caps lock LED: direct drive
LN	3.3kOhm R	nLED_NUM		Num lock LED: direct drive
LU	3.3kOhm R	SUSPEND		Valid in USB mode. High = keyboard is in suspend mode; low = normal running mode.
R0-7	Direct	ROW0-ROW7		Row lines 0 to 7 for scan matrix with internal pull-down resistor
C18-C19	Direct	COL18-COL19		Column lines for scan matrix
6-17	Direct	COL06-COL19		Column lines for scan matrix
0-5	Direct	COL00-COL05	Unmarked on board	Column lines for scan matrix