Shell - HAT Brick

This is the description of the Shell API bindings for the HAT Brick. General information and technical specifications for the HAT Brick 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).

Sleep

Download (example-sleep.sh)

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

uid=XXYYZZ # Change XXYYZZ to the UID of your HAT Brick

# Turn Raspberry Pi and Bricklets off in 2 seconds for 30 minutes with sleep indicator enabled
tinkerforge call hat-brick $uid set-sleep-mode 2 1800 true true true

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 hat-brick [<option>..] <uid> <function> [<argument>..]
Parameters:
  • <uid> – Type: String
  • <function> – Type: String

The call command is used to call a function of the HAT Brick. 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 HAT Brick and exits
tinkerforge dispatch hat-brick [<option>..] <uid> <callback>
Parameters:
  • <uid> – Type: String
  • <callback> – Type: String

The dispatch command is used to dispatch a callback of the HAT Brick. 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 HAT Brick and exits
tinkerforge call hat-brick <uid> <function> [<option>..] [<argument>..]
Parameters:
  • <uid> – Type: String
  • <function> – Type: 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 sent and errors are silently ignored, because they cannot be detected.

tinkerforge dispatch hat-brick <uid> <callback> [<option>..]
Parameters:
  • <uid> – Type: String
  • <callback> – Type: 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 hat-brick <uid> set-sleep-mode <power-off-delay> <power-off-duration> <raspberry-pi-off> <bricklets-off> <enable-sleep-indicator>
Parameters:
  • <power-off-delay> – Type: Int, Unit: 1 s, Range: [0 to 232 - 1]
  • <power-off-duration> – Type: Int, Unit: 1 s, Range: [0 to 232 - 1]
  • <raspberry-pi-off> – Type: Bool
  • <bricklets-off> – Type: Bool
  • <enable-sleep-indicator> – Type: Bool
Output:
  • no output

Sets the sleep mode.

Note

Calling this function will cut the Raspberry Pi's power after Power Off Delay seconds. You have to shut down the operating system yourself, e.g. by calling 'sudo shutdown -h now'.

Parameters:

  • Power Off Delay: Time before the RPi/Bricklets are powered off.
  • Power Off Duration: Duration that the RPi/Bricklets stay powered off.
  • Raspberry Pi Off: RPi is powered off if set to true.
  • Bricklets Off: Bricklets are powered off if set to true.
  • Enable Sleep Indicator: If set to true, the status LED will blink in a 1s interval during the whole power off duration. This will draw additional 0.3mA.

Example: To turn RPi and Bricklets off in 5 seconds for 10 minutes with sleep indicator enabled, call (5, 60*10, true, true, true).

This function can also be used to implement a watchdog. To do this you can write a program that calls this function once per second in a loop with (10, 2, true, false, false). If the RPi crashes or gets stuck the HAT will reset the RPi after 10 seconds.

tinkerforge call hat-brick <uid> get-sleep-mode
Output:
  • power-off-delay – Type: Int, Unit: 1 s, Range: [0 to 232 - 1]
  • power-off-duration – Type: Int, Unit: 1 s, Range: [0 to 232 - 1]
  • raspberry-pi-off – Type: Bool
  • bricklets-off – Type: Bool
  • enable-sleep-indicator – Type: Bool

Returns the sleep mode settings as set by set-sleep-mode.

tinkerforge call hat-brick <uid> set-bricklet-power <bricklet-power>
Parameters:
  • <bricklet-power> – Type: Bool, Default: true
Output:
  • no output

Set to true/false to turn the power supply of the connected Bricklets on/off.

tinkerforge call hat-brick <uid> get-bricklet-power
Output:
  • bricklet-power – Type: Bool, Default: true

Returns the power status of the connected Bricklets as set by set-bricklet-power.

tinkerforge call hat-brick <uid> get-voltages
Output:
  • voltage-usb – Type: Int, Unit: 1 mV, Range: [0 to 216 - 1]
  • voltage-dc – Type: Int, Unit: 1 mV, Range: [0 to 216 - 1]

Returns the USB supply voltage and the DC input supply voltage.

There are three possible combinations:

  • Only USB connected: The USB supply voltage will be fed back to the DC input connector. You will read the USB voltage and a slightly lower voltage on the DC input.
  • Only DC input connected: The DC voltage will not be fed back to the USB connector. You will read the DC input voltage and the USB voltage will be 0.
  • USB and DC input connected: You will read both voltages. In this case the USB supply will be without load, but it will work as backup if you disconnect the DC input (or if the DC input voltage falls below the USB voltage).

Advanced Functions

tinkerforge call hat-brick <uid> set-rtc-driver <rtc-driver>
Parameters:
  • <rtc-driver> – Type: Int, Range: See symbols
Output:
  • no output

Configures the RTC driver that is given to the Raspberry Pi to be used. Currently there are two different RTCs used:

  • Hardware version <= 1.5: PCF8523
  • Hardware version 1.6: DS1338

The correct driver will be set during factory flashing by Tinkerforge.

The following symbols are available for this function:

For <rtc-driver>:

  • rtc-driver-pcf8523 = 0
  • rtc-driver-ds1338 = 1

New in version 2.0.3 (Firmware).

tinkerforge call hat-brick <uid> get-rtc-driver
Output:
  • rtc-driver – Type: Int, Range: See symbols

Returns the RTC driver as set by set-rtc-driver.

The following symbols are available for this function:

For rtc-driver:

  • rtc-driver-pcf8523 = 0
  • rtc-driver-ds1338 = 1

New in version 2.0.3 (Firmware).

tinkerforge call hat-brick <uid> get-spitfp-error-count
Output:
  • error-count-ack-checksum – Type: Int, Range: [0 to 232 - 1]
  • error-count-message-checksum – Type: Int, Range: [0 to 232 - 1]
  • error-count-frame – Type: Int, Range: [0 to 232 - 1]
  • error-count-overflow – Type: Int, Range: [0 to 232 - 1]

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 hat-brick <uid> set-status-led-config <config>
Parameters:
  • <config> – Type: Int, Range: See symbols, Default: 3
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:

For <config>:

  • status-led-config-off = 0
  • status-led-config-on = 1
  • status-led-config-show-heartbeat = 2
  • status-led-config-show-status = 3
tinkerforge call hat-brick <uid> get-status-led-config
Output:
  • config – Type: Int, Range: See symbols, Default: 3

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

The following symbols are available for this function:

For config:

  • status-led-config-off = 0
  • status-led-config-on = 1
  • status-led-config-show-heartbeat = 2
  • status-led-config-show-status = 3
tinkerforge call hat-brick <uid> get-chip-temperature
Output:
  • temperature – Type: Int, Unit: 1 °C, Range: [-215 to 215 - 1]

Returns the temperature 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 hat-brick <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 hat-brick <uid> get-identity
Output:
  • uid – Type: String, Length: up to 8
  • connected-uid – Type: String, Length: up to 8
  • position – Type: Char, Range: [i]
  • hardware-version – Type: Int Array, Length: 3
    • 0: major – Type: Int, Range: [0 to 255]
    • 1: minor – Type: Int, Range: [0 to 255]
    • 2: revision – Type: Int, Range: [0 to 255]
  • firmware-version – Type: Int Array, Length: 3
    • 0: major – Type: Int, Range: [0 to 255]
    • 1: minor – Type: Int, Range: [0 to 255]
    • 2: revision – Type: Int, Range: [0 to 255]
  • device-identifier – Type: Int, Range: [0 to 216 - 1]

Returns the UID, the UID where the HAT is connected to (typically '0' as the HAT is the root device in the topology), the position, the hardware and firmware version as well as the device identifier.

The HAT (Zero) Brick is always at position 'i'.

The device identifier numbers can be found here

Callback Configuration Functions

tinkerforge call hat-brick <uid> set-voltages-callback-configuration <period> <value-has-to-change>
Parameters:
  • <period> – Type: Int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • <value-has-to-change> – Type: Bool, Default: false
Output:
  • no output

The period is the period with which the voltages callback is triggered periodically. A value of 0 turns the callback off.

If the value has to change-parameter is set to true, the callback is only triggered after the value has changed. If the value didn't change within the period, the callback is triggered immediately on change.

If it is set to false, the callback is continuously triggered with the period, independent of the value.

New in version 2.0.1 (Firmware).

tinkerforge call hat-brick <uid> get-voltages-callback-configuration
Output:
  • period – Type: Int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • value-has-to-change – Type: Bool, Default: false

Returns the callback configuration as set by set-voltages-callback-configuration.

New in version 2.0.1 (Firmware).

Callbacks

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

tinkerforge dispatch hat-brick <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 hat-brick <uid> voltages
Output:
  • voltage-usb – Type: Int, Unit: 1 mV, Range: [0 to 216 - 1]
  • voltage-dc – Type: Int, Unit: 1 mV, Range: [0 to 216 - 1]

This callback is triggered periodically according to the configuration set by set-voltages-callback-configuration.

The parameters are the same as get-voltages.

New in version 2.0.1 (Firmware).

Internal Functions

Internal functions are used for maintenance tasks such as flashing a new firmware of changing the UID of a Bricklet. These task should be performed using Brick Viewer instead of using the internal functions directly.

tinkerforge call hat-brick <uid> set-bootloader-mode <mode>
Parameters:
  • <mode> – Type: Int, Range: See symbols
Output:
  • status – Type: Int, Range: See 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:

For <mode>:

  • bootloader-mode-bootloader = 0
  • bootloader-mode-firmware = 1
  • bootloader-mode-bootloader-wait-for-reboot = 2
  • bootloader-mode-firmware-wait-for-reboot = 3
  • bootloader-mode-firmware-wait-for-erase-and-reboot = 4

For status:

  • bootloader-status-ok = 0
  • bootloader-status-invalid-mode = 1
  • bootloader-status-no-change = 2
  • bootloader-status-entry-function-not-present = 3
  • bootloader-status-device-identifier-incorrect = 4
  • bootloader-status-crc-mismatch = 5
tinkerforge call hat-brick <uid> get-bootloader-mode
Output:
  • mode – Type: Int, Range: See symbols

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

The following symbols are available for this function:

For mode:

  • bootloader-mode-bootloader = 0
  • bootloader-mode-firmware = 1
  • bootloader-mode-bootloader-wait-for-reboot = 2
  • bootloader-mode-firmware-wait-for-reboot = 3
  • bootloader-mode-firmware-wait-for-erase-and-reboot = 4
tinkerforge call hat-brick <uid> set-write-firmware-pointer <pointer>
Parameters:
  • <pointer> – Type: Int, Unit: 1 B, Range: [0 to 232 - 1]
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 hat-brick <uid> write-firmware <data>
Parameters:
  • <data> – Type: Int Array, Length: 64, Range: [0 to 255]
Output:
  • status – Type: Int, Range: [0 to 255]

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 hat-brick <uid> write-uid <uid>
Parameters:
  • <uid> – Type: Int, Range: [0 to 232 - 1]
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 hat-brick <uid> read-uid
Output:
  • uid – Type: Int, Range: [0 to 232 - 1]

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