Santek EZ Door Sign - Revision history

Leo at 03:09, 29 March 2025

2025-03-29T03:09:30Z

← Older revision		Revision as of 03:09, 29 March 2025
Line 219:		Line 219:
	\|Red		\|Red
	\|}		\|}
	For black and white only pictures, you ~~can effectively ignore setting~~ canvas=1.		For entirely black and white only pictures, you still need to write all 0's on the second canvas. Otherwise, the slide is will be rendered completely red. It's likely any unwritten data is erased to 0xFF on the flash.

Leo at 03:07, 29 March 2025

2025-03-29T03:07:49Z

Show changes

Leo: /* Commands */

2025-03-27T23:50:46Z

Commands

Show changes

Leo: /* Commands */

2025-03-27T07:05:31Z

Commands

← Older revision		Revision as of 07:05, 27 March 2025
Line 153:		Line 153:
	\|site+1		\|site+1
	\|0x7E		\|0x7E
	\|Redraws the slide		\|Redraws the slide (0 ~ 4)
	\|-		\|-
	\|0xBB		\|0xBB
			\|0x01
	\|0x00		\|0x00
			\|0x01
			\|site
			\|
			\|
			\|Redrew the slide ok.
			\|-
			\|0xBB
			\|0x00
			\|0x01
			\|0x01
			\|site
			\|variable
			\|0x7E
			\|Check if site is blank. if returned 4th byte is 254, then isBlank is false
			\|-
			\|0xBB
			\|0x01
	\|0x01		\|0x01
	\|0x01		\|0x01
Line 162:		Line 180:
	\|variable		\|variable
	\|0x7E		\|0x7E
	\|site is blank. ~~if 4th byte is 254, then isBlank is false~~		\|site given bacak is 0xFE, meaning slide is not blank.
	\|}		\|}
	The checksum is calculated by summing everything		The checksum is calculated by summing everything

Leo: /* Commands */

2025-03-27T06:54:59Z

Commands

← Older revision		Revision as of 06:54, 27 March 2025
Line 44:		Line 44:
	* site: slide number (0 through 4)		* site: slide number (0 through 4)
	* canvas: Color canvas (0 or 1)		* canvas: Color canvas (0 or 1)
			\|-
			\|0xBB
			\|0x01
			\|0x03
			\|0x01
			\|0x01
			\|
			\|0x7E
			\|did set image head data succeed? Data should be 0x01
	\|-		\|-
	\|0xBB		\|0xBB
Line 49:		Line 58:
	\|0x04		\|0x04
	\|0x12		\|0x12
	\|~~row~~-bitmap		\|column-bitmap
	\|variable		\|variable
	\|0x7E		\|0x7E
	\|send image ~~row~~ data.		\|send image bitmap data by column.
	Data is always 18 bytes long. 2 for ~~row~~ number, 16 for bitmap data.		Data is always 18 bytes long. 2 for column number, 16 for bitmap data.
	Bitmap data here is based on the canvas setting ~~(row above)~~
			Bitmap data here is based on the canvas setting in order to get that extra bit for color.

	* ~~Row~~: 2 bytes in decimal. 0x01, 0x27 ~~= 127~~		* Column: 2 bytes in decimal. (0 ~ 295) (0x00,0x00 ~ 0x01,0x27)
	* Bitmap: 16 bytes. One bit per pixel makes 128 pixels		* Bitmap: 16 bytes. One bit per pixel makes 128 pixels
			This is how you can retrieve data for the 296x128 pixel display.
			\|-
			\|0xBB
			\|0x01
			\|0x04
			\|0x01
			\|0x01
			\|
			\|0x7E
			\|did send image row data succeed? Data should be 0x01
	\|-		\|-
	\|0xBB		\|0xBB
Line 63:		Line 83:
	\|0x05		\|0x05
	\|0x04		\|0x04
	\|site-canvas-~~row~~		\|site-canvas-column
	\|variable		\|variable
	\|0x7E		\|0x7E
Line 71:		Line 91:
	* Site: Slide number (0 through 4)		* Site: Slide number (0 through 4)
	* Canvas: Color canvas (0 or 1)		* Canvas: Color canvas (0 or 1)
	* ~~Row~~: 2 bytes ~~in decimal~~. ~~0x01, 0x27 = 127~~		* Column: 2 bytes. (0 ~ 295)

	To retrieve the actual color, you have to read both canvas		To retrieve the actual color, you have to read both canvas
Line 81:		Line 101:
	\|0x05		\|0x05
	\|0x12		\|0x12
	\|~~row~~-bitmap		\|column-bitmap
	\|variable		\|variable
	\|0x7E		\|0x7E
	\|Bitmap data received from a get command. The response message is always 24 bytes long.		\|Bitmap data received from a get command. The response message is always 24 bytes long.
	There are 18 bytes of payload data and is the same format as the send-image-~~row~~ command.		There are 18 bytes of payload data and is the same format as the send-image-column command.

	* ~~Row~~: 2 bytes ~~in decimal~~. ~~0x01, 0x27 = 127~~		* Column: 2 bytes. (0 ~ 295)
	* Bitmap: 16 bytes. One bit per pixel makes 128 pixels		* Bitmap: 16 bytes. One bit per pixel makes 128 pixels
	\|-		\|-

Leo: /* Commands */

2025-03-27T06:02:24Z

Commands

← Older revision		Revision as of 06:02, 27 March 2025
Line 11:		Line 11:

	=== Serial configuration ===		=== Serial configuration ===
	9600 baud?		Use 9600 baud. No parity.

	~~Expects CH343 device id~~		The display has to be on. Ensure that the blue LED is lit before trying to talk to it via serial.

	=== Commands ===		=== Commands ===
	Here are some of the supported commands by the display.		Here are some of the supported commands by the display.

			Command Type is 0 if it's a command that's sent to the display. It will be a 1 if it's data that's a response to a command made by the display.
	{\| class="wikitable"		{\| class="wikitable"
	!Header		!Header
Line 73:		Line 75:
	To retrieve the actual color, you have to read both canvas		To retrieve the actual color, you have to read both canvas

	~~Data that's returned~~ is...~~???~~		See the response payload below.
			\|-
			\|0xBB
			\|0x01
			\|0x05
			\|0x12
			\|row-bitmap
			\|variable
			\|0x7E
			\|Bitmap data received from a get command. The response message is always 24 bytes long.
			There are 18 bytes of payload data and is the same format as the send-image-row command.

			* Row: 2 bytes in decimal. 0x01, 0x27 = 127
			* Bitmap: 16 bytes. One bit per pixel makes 128 pixels
	\|-		\|-
	\|0xBB		\|0xBB
Line 118:		Line 133:
	\|site+1		\|site+1
	\|0x7E		\|0x7E
	\|~~"assign site". Likely redraws~~ the ~~given~~ slide ~~#. Eg. slide=0~~		\|Redraws the slide
	\|-		\|-
	\|0xBB		\|0xBB
Line 129:		Line 144:
	\|site is blank. if 4th byte is 254, then isBlank is false		\|site is blank. if 4th byte is 254, then isBlank is false
	\|}		\|}
			The checksum is calculated by summing everything
	*		*

Line 136:		Line 151:
	* read and discard until you see 187		* read and discard until you see 187
	* ???		* ???

			=== Color data ===
			The <code>site-canvas-row</code> data that you read/write using the commands above determine the color. Because we only use one bit per canvas, the canvas is pretty much how you define an additional bit per pixel.
			{\| class="wikitable"
			!
			!Canvas = 0
			!Canvas = 1
			!Color
			\|-
			! rowspan="3" \|Pixel bit value
			\|0
			\|0
			\|Black
			\|-
			\|1
			\|0
			\|White
			\|-
			\|0
			\|1
			\|Red
			\|}
			For black and white only pictures, you can effectively ignore setting canvas=1.

Leo: Initial content

2025-03-27T05:09:05Z

Initial content

New page

The Santek EZ Door Sign is cordless e-ink display intended to be mounted outside of offices or rooms. It is capable of storing 5 custom images that can be displayed and rotated with the side button.

The 2.9" variant which I obtained has a resolution of 296 x 128 pixels and is capable of displaying black, white, and red.

== Serial protocol ==

=== Background ===
Santek provides a Windows based app written in C# that is able to interact with the door signs. My goal is to have some Linux based device that can periodically update these displays (such as the weather or calendar events on an hourly basis). In order to do that, I will need to figure out how exactly this device talks via the USB port.

There are some GitHub projects that try to interface with this device already including https://github.com/m3m0r7/ez-door-sign in PHP and https://github.com/kenichi884/ezsign.py in Python. However, the documentation on the serial protocol is a bit lacking. Fortunately, the protocol doesn't seem too complicated.

=== Serial configuration ===
9600 baud?

Expects CH343 device id

=== Commands ===
Here are some of the supported commands by the display.
{| class="wikitable"
!Header
!Command
Type
!Command
ID
!Data
Length
!Data
!Chksum
!Ending
!Notes
|-
|0xBB
|0x00
|0x03
|0x02
|site-canvas
|variable
|0x7E
|set image head data. This specifies which canvas you are overwriting.
Data is always 2 bytes long, containing:

* site: slide number (0 through 4)
* canvas: Color canvas (0 or 1)
|-
|0xBB
|0x00
|0x04
|0x12
|row-bitmap
|variable
|0x7E
|send image row data.
Data is always 18 bytes long. 2 for row number, 16 for bitmap data.
Bitmap data here is based on the canvas setting (row above)

* Row: 2 bytes in decimal. 0x01, 0x27 = 127
* Bitmap: 16 bytes. One bit per pixel makes 128 pixels
|-
|0xBB
|0x00
|0x05
|0x04
|site-canvas-row
|variable
|0x7E
|Get image bitmap from display memory.
Data is always 4 bytes long.

* Site: Slide number (0 through 4)
* Canvas: Color canvas (0 or 1)
* Row: 2 bytes in decimal. 0x01, 0x27 = 127

To retrieve the actual color, you have to read both canvas

Data that's returned is...???
|-
|0xBB
|
|0x06
|
|
|
|0x7E
|iap model
|-
|0xBB
|0x00
|0x07
|0x01
|0x00
|0x08
|0x7E
|power off
|-
|0xBB
|0x00
|0x00
|0x01
|0xFE
|0xFF
|0x7E
|next slide
|-
|0xBB
|0x00
|0x00
|0x01
|0xFF
|0x00
|0x7E
|previous slide (called 'up' in C# code)
|-
|0xBB
|0x00
|0x00
|0x01
|site
|site+1
|0x7E
|"assign site". Likely redraws the given slide #. Eg. slide=0
|-
|0xBB
|0x00
|0x01
|0x01
|site
|variable
|0x7E
|site is blank. if 4th byte is 254, then isBlank is false
|}

*

When reading data...

* read and discard until you see 187
* ???