..
  This file is part of GNU TALER.
  Copyright (C) 2014-2024 Taler Systems SA

  TALER is free software; you can redistribute it and/or modify it under the
  terms of the GNU Affero General Public License as published by the Free Software
  Foundation; either version 2.1, or (at your option) any later version.

  TALER is distributed in the hope that it will be useful, but WITHOUT ANY
  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more details.

  You should have received a copy of the GNU Affero General Public License along with
  TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>

  @author Christian Grothoff


taler-mdb.conf(5)
#################

.. only:: html

   Name
   ====

   **taler-mdb.conf** - Taler-mdb configuration file


Description
===========

.. include:: ../frags/common-conf-syntax.rst

Files containing default values for many of the options described below
are installed under ``$TALER_PREFIX/share/taler-exchange/config.d/``.
The configuration file given with **-c** to Taler binaries
overrides these defaults.

A configuration file may include another, by using the ``@INLINE@`` directive,
for example, in ``main.conf``, you could write ``@INLINE@ sub.conf`` to
include the entirety of ``sub.conf`` at that point in ``main.conf``.


Taler-mdb Options
-----------------

Taler-mdb is a component to run GNU Taler as a payment system on
vending machines using the multi-drop bus protocol. These options
are thus not useful for most users.  Note that right now, the
cancel button is hard-coded to be using GPIO pin 23.

ADVERTISEMENT_COMMAND
  Program to run while not vending, possibly useful to show advertisements on the screen (optional).
ESSID
  ESSID to advertise to wallets for use as an open WiFi to make payments (optional).
FULFILLMENT_MSG
  Message shown to users by their wallets upon successful payment. If "${PRODUCT_DESCRIPTION}" appears in the message, it will be replaced with the description of the product that was sold.
BACKEND_BASE_URL
  Base URL (possibly including instance) for the Taler merchant backend used to process payments.
BACKEND_AUTHORIZATION
  Full HTTP "Authorization" header (usually with a Bearer token) to be send to the merchant backend for authorization of requests. Mandatory.
FRAMEBUFFER_BACKLIGHT
  Name of the file used to control brightness of the display. Optional. Defaults to "/sys/class/backlight/soc:backlight/brightness" if not given.
FRAMEBUFFER_DEVICE
  Name of the framebuffer device to use. Defaults to "/dev/fb1" if not given.
UART_DEVICE
  Name of the UART device to use. Defaults to "/dev/ttyAMA0" if not given.
FAIL_COMMAND
  Command to run by taler-mdb to display a failure to the user. If not given, errors will not be properly shown. Should usually be set to "taler-mdb-show.sh".
FAIL_HELPER
  Command used by taler-mdb-network-check.sh to run to display a failure to the user. If not given, errors will not be properly shown. Should usually be set to "taler-mdb-show.sh".

Each products being sold must be configured in a section where the name starts with "product-".
In these sections, the options that must be provided are:

NUMBER
  Number identifying the slot in the vending machine that corresponds to this product.
INSTANCE
  Instance to use for the payment. Optional. If not given, the BACKEND_BASE_URL from "[taler-mdb]" will be used.
BACKEND_AUTHORIZATION
  Full HTTP "Authorization" header (usually with a Bearer token) to be send to the merchant backend for authorization of requests. Optional, will use global BACKEND_AUTHORIZATION setting from "[taler-mdb]" if missing.
DESCRIPTION
  Human-readable description of the product. Use "empty" if the product is known to be sold out (only effective if selling out is enabled via command-line).
PRICE
  Actual price of the product, as a Taler amount ("$CURRENCY:$VALUE.$FRACTION").
KEY
  Key used to select the product from the console during testing. Optional.
THUMBNAIL
  Name of a filename with a preview image of the product to be given to the wallet. Optional. Only ".png", ".jpg", ".jpeg" and ".svg" are supported at this time.


SEE ALSO
========

taler-mdb(1), taler-mdb-qr-show(1), taler-mdb-display(1)

BUGS
====

Report bugs by using https://bugs.taler.net/ or by sending electronic
mail to <taler@gnu.org>.