Shell - E-Paper 296x128 Bricklet

This is the description of the Shell API bindings for the E-Paper 296x128 Bricklet. General information and technical specifications for the E-Paper 296x128 Bricklet are summarized in its hardware description.

An installation guide for the Shell API bindings is part of their general description.

Examples

The example code below is Public Domain (CC0 1.0).

Hello World

Download (example-hello-world.sh)

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#!/bin/sh
# Connects to localhost:4223 by default, use --host and --port to change this

uid=XYZ # Change XYZ to the UID of your E-Paper 296x128 Bricklet

# Use black background
tinkerforge call e-paper-296x128-bricklet $uid fill-display color-black

# Write big white "Hello World" in the middle of the screen
tinkerforge call e-paper-296x128-bricklet $uid draw-text 16 48 font-24x32 color-white orientation-horizontal "Hello World"
tinkerforge call e-paper-296x128-bricklet $uid draw

API

Possible exit codes for all tinkerforge commands are:

  • 1: interrupted (ctrl+c)
  • 2: syntax error
  • 21: Python 2.5 or newer is required
  • 22: Python argparse module is missing
  • 23: socket error
  • 24: other exception
  • 25: invalid placeholder in format string
  • 26: authentication error
  • 201: timeout occurred
  • 209: invalid argument value
  • 210: function is not supported
  • 211: unknown error

Command Structure

The common options of the call and dispatch commands are documented here. The specific command structure is shown below.

tinkerforge call e-paper-296x128-bricklet [<option>..] <uid> <function> [<argument>..]
Parameters:
  • <uid> -- string
  • <function> -- string

The call command is used to call a function of the E-Paper 296x128 Bricklet. It can take several options:

  • --help shows help for the specific call command and exits
  • --list-functions shows a list of known functions of the E-Paper 296x128 Bricklet and exits
tinkerforge dispatch e-paper-296x128-bricklet [<option>..] <uid> <callback>
Parameters:
  • <uid> -- string
  • <callback> -- string

The dispatch command is used to dispatch a callback of the E-Paper 296x128 Bricklet. It can take several options:

  • --help shows help for the specific dispatch command and exits
  • --list-callbacks shows a list of known callbacks of the E-Paper 296x128 Bricklet and exits
tinkerforge call e-paper-296x128-bricklet <uid> <function> [<option>..] [<argument>..]
Parameters:
  • <uid> -- string
  • <function> -- string

The <function> to be called can take different options depending of its kind. All functions can take the following options:

  • --help shows help for the specific function and exits

Getter functions can take the following options:

  • --execute <command> shell command line to execute for each incoming response (see section about output formatting for details)

Setter functions can take the following options:

  • --expect-response requests response and waits for it

The --expect-response option for setter functions allows to detect timeouts and other error conditions calls of setters as well. The device will then send a response for this purpose. If this option is not given for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

tinkerforge dispatch e-paper-296x128-bricklet <uid> <callback> [<option>..]
Parameters:
  • <uid> -- string
  • <callback> -- string

The <callback> to be dispatched can take several options:

  • --help shows help for the specific callback and exits
  • --execute <command> shell command line to execute for each incoming response (see section about output formatting for details)

Basic Functions

tinkerforge call e-paper-296x128-bricklet <uid> draw
Output:no output

Draws the current black/white and red or gray buffer to the e-paper display.

The Bricklet does not have any double-buffering. You should not call this function while writing to the buffer. See get-draw-status.

tinkerforge call e-paper-296x128-bricklet <uid> get-draw-status
Output:
  • draw-status -- int (has symbols)

Returns one of three draw statuses:

  • Idle
  • Copying: Data is being copied from the buffer of the Bricklet to the buffer of the display.
  • Drawing: The display is updating its content (during this phase the flickering etc happens).

You can write to the buffer (through one of the write or draw functions) when the status is either idle or drawing. You should not write to the buffer while it is being copied to the display. There is no double-buffering.

The following symbols are available for this function:

  • draw-status-idle = 0, for draw-status
  • draw-status-copying = 1, for draw-status
  • draw-status-drawing = 2, for draw-status
tinkerforge call e-paper-296x128-bricklet <uid> write-black-white-low-level <x-start> <y-start> <x-end> <y-end> <pixels-length> <pixels-chunk-offset> <pixels-chunk-data>
Parameters:
  • <x-start> -- int
  • <y-start> -- int
  • <x-end> -- int
  • <y-end> -- int
  • <pixels-length> -- int
  • <pixels-chunk-offset> -- int
  • <pixels-chunk-data> -- bool,bool,..429x..,bool
Output:

no output

Writes black/white pixels to the specified window into the buffer.

The x-axis goes from 0 to 295 and the y-axis from 0 to 127. The pixels are written into the window line by line top to bottom and each line is written from left to right.

The value 0 (false) corresponds to a black pixel and the value 1 (true) to a white pixel.

This function writes the pixels into the black/white pixel buffer, to draw the buffer to the display use draw.

Use write-color to write red or gray pixels.

tinkerforge call e-paper-296x128-bricklet <uid> read-black-white-low-level <x-start> <y-start> <x-end> <y-end>
Parameters:
  • <x-start> -- int
  • <y-start> -- int
  • <x-end> -- int
  • <y-end> -- int
Output:
  • pixels-length -- int
  • pixels-chunk-offset -- int
  • pixels-chunk-data -- bool,bool,..461x..,bool

Returns the current content of the black/white pixel buffer for the specified window.

The x-axis goes from 0 to 295 and the y-axis from 0 to 127. The pixels are written into the window line by line top to bottom and each line is written from left to right.

The current content of the buffer does not have to be the current content of the display. It is possible that the data was not drawn to the display yet and after a restart of the Bricklet the buffer will be reset to black, while the display retains its content.

tinkerforge call e-paper-296x128-bricklet <uid> write-color-low-level <x-start> <y-start> <x-end> <y-end> <pixels-length> <pixels-chunk-offset> <pixels-chunk-data>
Parameters:
  • <x-start> -- int
  • <y-start> -- int
  • <x-end> -- int
  • <y-end> -- int
  • <pixels-length> -- int
  • <pixels-chunk-offset> -- int
  • <pixels-chunk-data> -- bool,bool,..429x..,bool
Output:

no output

The E-Paper 296x128 Bricklet is available with the colors black/white/red and black/white/gray. Depending on the model this function writes either red or gray pixels to the specified window into the buffer.

The x-axis goes from 0 to 295 and the y-axis from 0 to 127. The pixels are written into the window line by line top to bottom and each line is written from left to right.

The value 0 (false) means that this pixel does not have color. It will be either black or white (see write-black-white). The value 1 (true) corresponds to a red or gray pixel, depending on the Bricklet model.

This function writes the pixels into the red or gray pixel buffer, to draw the buffer to the display use draw.

Use write-black-white to write black/white pixels.

tinkerforge call e-paper-296x128-bricklet <uid> read-color-low-level <x-start> <y-start> <x-end> <y-end>
Parameters:
  • <x-start> -- int
  • <y-start> -- int
  • <x-end> -- int
  • <y-end> -- int
Output:
  • pixels-length -- int
  • pixels-chunk-offset -- int
  • pixels-chunk-data -- bool,bool,..461x..,bool

Returns the current content of the red or gray pixel buffer for the specified window.

The x-axis goes from 0 to 295 and the y-axis from 0 to 127. The pixels are written into the window line by line top to bottom and each line is written from left to right.

The current content of the buffer does not have to be the current content of the display. It is possible that the data was not drawn to the display yet and after a restart of the Bricklet the buffer will be reset to black, while the display retains its content.

tinkerforge call e-paper-296x128-bricklet <uid> fill-display <color>
Parameters:
  • <color> -- int (has symbols)
Output:

no output

Fills the complete content of the display with the given color.

The following symbols are available for this function:

  • color-black = 0, for <color>
  • color-white = 1, for <color>
  • color-red = 2, for <color>
  • color-gray = 2, for <color>
tinkerforge call e-paper-296x128-bricklet <uid> draw-text <position-x> <position-y> <font> <color> <orientation> <text>
Parameters:
  • <position-x> -- int
  • <position-y> -- int
  • <font> -- int (has symbols)
  • <color> -- int (has symbols)
  • <orientation> -- int (has symbols)
  • <text> -- string
Output:

no output

Draws a text with up to 50 characters at the pixel position (x, y).

The x values have to be within the range of 0 to 295 and the y values have to be within the range of 0 to 127.

You can use one of 9 different font sizes and draw the text in black/white/red|gray. The text can be drawn horizontal or vertical.

The following symbols are available for this function:

  • font-6x8 = 0, for <font>
  • font-6x16 = 1, for <font>
  • font-6x24 = 2, for <font>
  • font-6x32 = 3, for <font>
  • font-12x16 = 4, for <font>
  • font-12x24 = 5, for <font>
  • font-12x32 = 6, for <font>
  • font-18x24 = 7, for <font>
  • font-18x32 = 8, for <font>
  • font-24x32 = 9, for <font>
  • color-black = 0, for <color>
  • color-white = 1, for <color>
  • color-red = 2, for <color>
  • color-gray = 2, for <color>
  • orientation-horizontal = 0, for <orientation>
  • orientation-vertical = 1, for <orientation>
tinkerforge call e-paper-296x128-bricklet <uid> draw-line <position-x-start> <position-y-start> <position-x-end> <position-y-end> <color>
Parameters:
  • <position-x-start> -- int
  • <position-y-start> -- int
  • <position-x-end> -- int
  • <position-y-end> -- int
  • <color> -- int (has symbols)
Output:

no output

Draws a line from (x, y)-start to (x, y)-end in the given color. The x values have to be within the range of 0 to 295 and the y values have t be within the range of 0 to 127.

The following symbols are available for this function:

  • color-black = 0, for <color>
  • color-white = 1, for <color>
  • color-red = 2, for <color>
  • color-gray = 2, for <color>
tinkerforge call e-paper-296x128-bricklet <uid> draw-box <position-x-start> <position-y-start> <position-x-end> <position-y-end> <fill> <color>
Parameters:
  • <position-x-start> -- int
  • <position-y-start> -- int
  • <position-x-end> -- int
  • <position-y-end> -- int
  • <fill> -- bool
  • <color> -- int (has symbols)
Output:

no output

Draws a box from (x, y)-start to (x, y)-end in the given color. The x values have to be within the range of 0 to 295 and the y values have to be within the range of 0 to 127.

If you set fill to true, the box will be filled with the color. Otherwise only the outline will be drawn.

The following symbols are available for this function:

  • color-black = 0, for <color>
  • color-white = 1, for <color>
  • color-red = 2, for <color>
  • color-gray = 2, for <color>

Advanced Functions

tinkerforge call e-paper-296x128-bricklet <uid> set-update-mode <update-mode>
Parameters:
  • <update-mode> -- int (has symbols)
Output:

no output

Note

The default update mode corresponds to the default e-paper display manufacturer settings. All of the other modes are experimental and will result in increased ghosting and possibly other long-term side effects.

If you want to know more about the inner workings of an e-paper display take a look at this excellent video from Ben Krasnow: https://www.youtube.com/watch?v=MsbiO8EAsGw.

If you are not sure about this option, leave the update mode at default.

Currently there are three update modes available:

  • Default: Settings as given by the manufacturer. An update will take about 7.5 seconds and during the update the screen will flicker several times.
  • Black/White: This will only update the black/white pixel. It uses the manufacturer settings for black/white and ignores the red or gray pixel buffer. With this mode the display will flicker once and it takes about 2.5 seconds. Compared to the default settings there is more ghosting.
  • Delta: This will only update the black/white pixel. It uses an aggressive method where the changes are not applied for a whole buffer but only for the delta between the last and the next buffer. With this mode the display will not flicker during an update and it takes about 900-950ms. Compared to the other two settings there is more ghosting. This mode can be used for something like a flicker-free live update of a text.

With the black/white/red display if you use either the black/white or the delta mode, after a while of going back and forth between black and white the white color will start to appear red-ish or pink-ish.

If you use the aggressive delta mode and rapidly change the content, we recommend that you change back to the default mode every few hours and in the default mode cycle between the three available colors a few times. This will get rid of the ghosting and after that you can go back to the delta mode with flicker-free updates.

The following symbols are available for this function:

  • update-mode-default = 0, for <update-mode>
  • update-mode-black-white = 1, for <update-mode>
  • update-mode-delta = 2, for <update-mode>
tinkerforge call e-paper-296x128-bricklet <uid> get-update-mode
Output:
  • update-mode -- int (has symbols)

Returns the update mode as set by set-update-mode.

The following symbols are available for this function:

  • update-mode-default = 0, for update-mode
  • update-mode-black-white = 1, for update-mode
  • update-mode-delta = 2, for update-mode
tinkerforge call e-paper-296x128-bricklet <uid> set-display-type <display-type>
Parameters:
  • <display-type> -- int (has symbols)
Output:

no output

Sets the type of the display. The e-paper display is available in black/white/red and black/white/gray. This will be factory set during the flashing and testing phase. The value is saved in non-volatile memory and will stay after a power cycle.

The following symbols are available for this function:

  • display-type-black-white-red = 0, for <display-type>
  • display-type-black-white-gray = 1, for <display-type>
tinkerforge call e-paper-296x128-bricklet <uid> get-display-type
Output:
  • display-type -- int (has symbols)

Returns the type of the e-paper display. It can either be black/white/red or black/white/gray.

The following symbols are available for this function:

  • display-type-black-white-red = 0, for display-type
  • display-type-black-white-gray = 1, for display-type
tinkerforge call e-paper-296x128-bricklet <uid> get-spitfp-error-count
Output:
  • error-count-ack-checksum -- int
  • error-count-message-checksum -- int
  • error-count-frame -- int
  • error-count-overflow -- int

Returns the error count for the communication between Brick and Bricklet.

The errors are divided into

  • ACK checksum errors,
  • message checksum errors,
  • framing errors and
  • overflow errors.

The errors counts are for errors that occur on the Bricklet side. All Bricks have a similar function that returns the errors on the Brick side.

tinkerforge call e-paper-296x128-bricklet <uid> set-bootloader-mode <mode>
Parameters:
  • <mode> -- int (has symbols)
Output:
  • status -- int (has symbols)

Sets the bootloader mode and returns the status after the requested mode change was instigated.

You can change from bootloader mode to firmware mode and vice versa. A change from bootloader mode to firmware mode will only take place if the entry function, device identifier and CRC are present and correct.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

The following symbols are available for this function:

  • bootloader-mode-bootloader = 0, for <mode>
  • bootloader-mode-firmware = 1, for <mode>
  • bootloader-mode-bootloader-wait-for-reboot = 2, for <mode>
  • bootloader-mode-firmware-wait-for-reboot = 3, for <mode>
  • bootloader-mode-firmware-wait-for-erase-and-reboot = 4, for <mode>
  • bootloader-status-ok = 0, for status
  • bootloader-status-invalid-mode = 1, for status
  • bootloader-status-no-change = 2, for status
  • bootloader-status-entry-function-not-present = 3, for status
  • bootloader-status-device-identifier-incorrect = 4, for status
  • bootloader-status-crc-mismatch = 5, for status
tinkerforge call e-paper-296x128-bricklet <uid> get-bootloader-mode
Output:
  • mode -- int (has symbols)

Returns the current bootloader mode, see set-bootloader-mode.

The following symbols are available for this function:

  • bootloader-mode-bootloader = 0, for mode
  • bootloader-mode-firmware = 1, for mode
  • bootloader-mode-bootloader-wait-for-reboot = 2, for mode
  • bootloader-mode-firmware-wait-for-reboot = 3, for mode
  • bootloader-mode-firmware-wait-for-erase-and-reboot = 4, for mode
tinkerforge call e-paper-296x128-bricklet <uid> set-write-firmware-pointer <pointer>
Parameters:
  • <pointer> -- int
Output:

no output

Sets the firmware pointer for write-firmware. The pointer has to be increased by chunks of size 64. The data is written to flash every 4 chunks (which equals to one page of size 256).

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

tinkerforge call e-paper-296x128-bricklet <uid> write-firmware <data>
Parameters:
  • <data> -- int,int,..61x..,int
Output:
  • status -- int

Writes 64 Bytes of firmware at the position as written by set-write-firmware-pointer before. The firmware is written to flash every 4 chunks.

You can only write firmware in bootloader mode.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

tinkerforge call e-paper-296x128-bricklet <uid> set-status-led-config <config>
Parameters:
  • <config> -- int (has symbols)
Output:

no output

Sets the status LED configuration. By default the LED shows communication traffic between Brick and Bricklet, it flickers once for every 10 received data packets.

You can also turn the LED permanently on/off or show a heartbeat.

If the Bricklet is in bootloader mode, the LED is will show heartbeat by default.

The following symbols are available for this function:

  • status-led-config-off = 0, for <config>
  • status-led-config-on = 1, for <config>
  • status-led-config-show-heartbeat = 2, for <config>
  • status-led-config-show-status = 3, for <config>
tinkerforge call e-paper-296x128-bricklet <uid> get-status-led-config
Output:
  • config -- int (has symbols)

Returns the configuration as set by set-status-led-config

The following symbols are available for this function:

  • status-led-config-off = 0, for config
  • status-led-config-on = 1, for config
  • status-led-config-show-heartbeat = 2, for config
  • status-led-config-show-status = 3, for config
tinkerforge call e-paper-296x128-bricklet <uid> get-chip-temperature
Output:
  • temperature -- int

Returns the temperature in °C as measured inside the microcontroller. The value returned is not the ambient temperature!

The temperature is only proportional to the real temperature and it has bad accuracy. Practically it is only useful as an indicator for temperature changes.

tinkerforge call e-paper-296x128-bricklet <uid> reset
Output:no output

Calling this function will reset the Bricklet. All configurations will be lost.

After a reset you have to create new device objects, calling functions on the existing ones will result in undefined behavior!

tinkerforge call e-paper-296x128-bricklet <uid> write-uid <uid>
Parameters:
  • <uid> -- int
Output:

no output

Writes a new UID into flash. If you want to set a new UID you have to decode the Base58 encoded UID string into an integer first.

We recommend that you use Brick Viewer to change the UID.

tinkerforge call e-paper-296x128-bricklet <uid> read-uid
Output:
  • uid -- int

Returns the current UID as an integer. Encode as Base58 to get the usual string version.

tinkerforge call e-paper-296x128-bricklet <uid> get-identity
Output:
  • uid -- string
  • connected-uid -- string
  • position -- char
  • hardware-version -- int,int,int
  • firmware-version -- int,int,int
  • device-identifier -- int (has symbols)

Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.

The position can be 'a', 'b', 'c' or 'd'.

The device identifier numbers can be found here

Callbacks

Callbacks can be used to receive time critical or recurring data from the device:

tinkerforge dispatch e-paper-296x128-bricklet <uid> example

The available callbacks are described below.

Note

Using callbacks for recurring events is always preferred compared to using getters. It will use less USB bandwidth and the latency will be a lot better, since there is no round trip time.

tinkerforge dispatch e-paper-296x128-bricklet <uid> draw-status
Output:
  • draw-status -- int (has symbols)

Callback for the current draw status. Will be called every time the draw status changes (see get-draw-status).

The following symbols are available for this function:

  • draw-status-idle = 0, for draw-status
  • draw-status-copying = 1, for draw-status
  • draw-status-drawing = 2, for draw-status