remove unused library

README.md

@@ -1,4 +1,4 @@
-This firmware template is designed for development boards based around [STM32 F1 series micro-controller](http://www.st.com/web/en/catalog/mmc/FM141/SC1169/SS1031).
+The dachtür is a device to restrict access to the dachboden.
 
 project
 =======
@@ -6,51 +6,161 @@ project
 summary
 -------
 
-*describe project purpose*
+Previously a button allowed to open the building's entrance door and granted access to the dachboden.
+Since the dachboden got popular, it is now flooded.
+The idea behind the dachtür it to disable this button and replace it with a secret sequence of button presses during certain periods (e.g. when parties are taking place in the dachboden).
+It must be installed in the door panel, as described under `connections`.
 
-technology
-----------
+configure
+---------
 
-*described electronic details*
+To program the days, times, and button sequence, connect to the dachtür.
+It should appear as "dachtuer" Bluetooth (classic) device.
+A PIN is required to connect to it.
+Once connected, you can use a terminal (such as the "Bluetooth terminal" android application).
+Interact with it by entering commands.
+- from time to time, update the date (it does not take into account summer and winter time):
+~~~
+date YYYY-MM-DD HH:MM
+~~~
+- enter the days on which the access should be restricted (starting with Monday, here only Thursday is active):
+~~~
+days 0001000
+~~~
+- enter at which time the restriction should start:
+~~~
+start 20:00
+~~~
+- enter at which time the restriction should stop:
+~~~
+stop 06:00
+~~~
+- enter the secret button sequence to open the door (here press button 1 then 2):
+~~~
+password 12
+~~~
 
-board
-=====
-
-The current implementation uses a [core board](https://wiki.cuvoodoo.info/doku.php?id=stm32f1xx#core_board).
-
-The underlying template also supports following board:
-
-- [Maple Mini](http://leaflabs.com/docs/hardware/maple-mini.html), based on a STM32F103CBT6
-- [System Board](https://wiki.cuvoodoo.info/doku.php?id=stm32f1xx#system_board), based on a STM32F103C8T6
-- [blue pill](https://wiki.cuvoodoo.info/doku.php?id=stm32f1xx#blue_pill), based on a STM32F103C8T6
-- [black pill](https://wiki.cuvoodoo.info/doku.php?id=stm32f1xx#black_pill), based on a STM32F103C8T6
-- [core board](https://wiki.cuvoodoo.info/doku.php?id=stm32f1xx#core_board), based on a STM32F103C8T6
-- [ST-LINK V2 mini](https://wiki.cuvoodoo.info/doku.php?id=jtag#mini_st-link_v2), a ST-LINK/V2 clone based on a STM32F101C8T6
-- [USB-Blaster](https://wiki.cuvoodoo.info/doku.php?id=jtag#armjishu_usb-blaster), an Altera USB-Blaster clone based on a STM32F101C8T6
-
-**Which board is used is defined in the Makefile**.
-This is required to map the user LED and button provided on the board
-
-The ST-LINK V2 mini clone has SWD test points on the board.
-Because read protection is enabled, you will first need to remove the protection to be able to flash the firmware.
-To remove the read protection (and erase flash), run `rake remove_protection` while a SWD adapter is connected.
-
-The Altera USB-Blaster clone has a pin header for SWD and UART1 on the board.
-SWD is disabled in the main firmware, and it has read protection.
-To be able to flash using SWD (or the serial port), the BOOT0 pin must be set to 1 to boot the system memory install of the flash memory.
-To set BOOT0 to 1, apply 3.3 V on R11, between the resistor and the reference designator, when powering the device.
-The red LED should stay off while the green LED is on.
-Now you can remove the read protection (and erase flash), run `rake remove_protection` while a SWD adapter is connected.
+WARNING: If the internal backup battery gets empty and the device looses power, the configuration and date get lost (since there are stored in SRAM).
+In this case, replace the battery and reconfigure the device.
 
 connections
 ===========
 
-Connect the peripherals the following way (STM32F10X signal; STM32F10X pin; peripheral pin; peripheral signal; comment):
+On one side there are three XH-2.54 connectors.
 
-- *list board to peripheral pin connections*
+2-pin connector: 6-25 AC/DC power input
+
+3-pin connector: opening button (the one already wired)
+- 1 (left-most): common side of button (leave the bus bar connected)
+- 2 (center): other side of the button (remove the cable)
+- 3 (right-most): the cable which was connected to the button
+
+4-pin connector: ring buttons (yet unused)
+- 2 left-most pins: to button 1 of door panel
+- 2 right-most pins: to button 2 of door panel
+
+On the other side is a USB connector.
+This is used to flash and configure the micro-controller.
+
+peripherals
+===========
+
+The XH-2.54 2P connector is for the 15V AC power input.
+A full bridge rectifier and smoothing capacitor make a DC power supply out of it.
+A buck converter module steps it down to 5V.
+Under 50 mA of power consumption it is very inefficient.
+With no load it has a quiescent current of 37 mA.
+The 5V rail provides power to the blue pill, Bluetooth module, and boost converter.
+
+The MT3608-based boost converter steps the voltage up to 9V for the omrom G6E-134P relays.
+It is more efficient to re-use the existing 5V than stepping down the 15V because the buck converters drawn a large current under no load.
+
+The XH-2.54 3P is to be connected to door opening button (the installer will know what I mean).
+Two omrom G6E-134P relays will take control over the button.
+This allows the door button to be used.
+At the specified time intervals, this is disconnected.
+When the right code is entered, the second relay simulates the button press and opens the door.
+The relays are controlled by the board using two 2N7000 n-channel MOSFETs.
+
+The XH-2.54 4P is to be connected with the two buttons.
+They are used to enter the secret sequence to open the door.
+
+The [blue pill](https://wiki.cuvoodoo.info/doku.php?id=stm32f1xx#blue_pill), based on a STM32F103C8T6 micro-controller, will handle the logic.
+
+A CR2032 battery is connected through a diode to VBAT.
+This keeps the real time clock (RTC) running when there is no power from the panel.
+A 3.3V pin is also connected through a diode to VBAT.
+This powered the RTC when the board is powered, saving the battery.
+
+The HC-05 Bluetooth module allows to remotely connect to the UART port.
+It has been configured (using `hc-05_porg.rb`) to appear as "dachtuer", and requires a PIN to pair.
+It offers the Serial Port Profile (SPP) from Bluetooth classic (Bluetooth Low Energy makes little sense).
+This allows to communicate with the board without having to remove the panel.
+It can be used to configure the opening time slots, days, and button sequence.
+It is also possible to update the firmware through it.
+
+A WS2812B LED strip is also connected to the board.
+The LEDs should be placed behind the button name shield.
+An animation with be shown when pressing the button (only during opening hours).
+
+wiring
+======
+
+HC-05 Bluetooth module:
+- STATE: no connect
+- TXD: PA10/USART1_RX
+- RXD: PA9/USART1_TX 
+- GND: ground
+- VCC: 5V
+- EN: no connect
+
+CR2032 coin cell battery:
+- +: VBAT, though diode (VBAT should also be connected to 3.3V through diode)
+- -: ground
+
+LED (because the on-board LED screws the LSE):
+- anode: 3.3V, though resistor (1K)
+- cathode: PB11
+
+omrom G6E-134P relay (bottom, for button):
+- 1 +: 9V
+- 6 -: 2N7000 drain
+- 7 COM: door button bar
+- 10 NC: no connect
+- 12 NO: other relay NO
+
+2N7000 p-channel MOSFET (for bottom relay):
+- 1 source: ground
+- 2 gate: PB6 (pulled low)
+- 3 drain: relay -
+
+omrom G6E-134P relay (top, for panel):
+- 1 +: 9V
+- 6 -: 2N7000 drain
+- 7 COM: wire to panel
+- 10 NC: door button (where the wire was)
+- 12 NO: other relay NO
+
+2N7000 p-channel MOSFET (for top relay):
+- 1 source: ground
+- 2 gate: PB7 (pulled low)
+- 3 drain: relay -
+
+WS2812B RGB LED strip:
+- VCC: 5V
+- DIN: PB15
+- GND: ground
+
+XH-4P:
+- 1: ground (for button 1)
+- 2: PB8 (for button 1)
+- 3: ground (for button 2)
+- 4: PB9 (for button 2)
 
 All pins are configured using `define`s in the corresponding source code.
 
+The prototype uses a SZOMK AK-N-01 enclosures salvaged from a J-Link clone.
+
 code
 ====
 
@@ -81,16 +191,35 @@ The `bootloader` is started first and immediately jumps to the `application` if
 The `application` image is the main application and is implemented in `application.c`.
 It is up to the application to advertise USB DFU support (i.e. as does the provided USB CDC ACM example).
 
-The `bootloader` image will be flashed using SWD (Serial Wire Debug).
+The `bootlaoder` image will be flashed using SWD (Serial Wire Debug).
 For that you need an SWD adapter.
-The `Makefile` uses a ST-Link V2 programmer along OpenOCD software (default), or Black Magic Probe.
+The `Makefile` uses a ST-Link V2 along OpenOCD software.
 To flash the `booltoader` using SWD run `rake flash_booloader`.
-If the development board uses the CKS32 chip STM32 alternative, use `CPUTAPID=0x2ba01477 rake flash_booloader`.
 
 Once the `bootloader` is flashed it is possible to flash the `application` over USB using the DFU protocol by running `rake flash`.
 To force the bootloader to start the DFU mode press the user button or short a pin, depending on the board.
 It is also possible to flash the `application` image using SWD by running `rake flash_application`.
 
+It is also possible to flash the application over Bluetooth as follows:
+~~~
+# start bluetooth
+sudo systemctl restart bluetooth
+# pair device (you only need to do it once, and you need the PIN)
+bluetoothctl
+power on
+pair 20:15:02:02:16:28
+quit
+# connect to device
+sudo rfcomm bind rfcomm0 20:15:02:02:16:28
+# switch to bootloader
+echo "embedded" > /dev/rfcomm0
+# flash firmware (it always fails the first time)
+stm32flash /dev/rfcomm0
+stm32flash /dev/rfcomm0 -b 115200 -S 0x08002000 -w application.bin -R
+# disconnect from device
+sudo rfcomm release rfcomm0
+~~~
+
 debug
 -----
 
@@ -100,4 +229,4 @@ To start the debugging session run `rake debug`.
 USB
 ---
 
-The firmware offers serial communication over USART1 and USB (using the CDC ACM device class).
+The firmware offers serial communication over USART1 (where the Bluetooth module is connected) and USB (using the CDC ACM device class).

Rakefile

@@ -193,8 +193,6 @@ OOCD_INTERFACE = ENV["OOCD_INTERFACE"] || (SWD_ADAPTER=="STLINKV2" ? "stlink" :
 OOCD_TARGET = "stm32f1x"
 # Black Magic Probe port
 BMP_PORT = ENV["BMP_PORT"] || "/dev/ttyACM0"
-# set CPUTAPID (0x1ba01477 for STM32, 0x2ba01477 for CKS32/APM32)
-CPUTAPID = ENV["CPUTAPID"] || "0x1ba01477"
 
 desc "flash application using USB DFU"
 task :flash => APPLICATION+".bin" do |t|
@@ -205,7 +203,7 @@ desc "remove STM32F1 protection using SWD"
 task :remove_protection do
   case SWD_ADAPTER
     when "STLINKV2"
-      sh "#{OOCD} --file interface/#{OOCD_INTERFACE}.cfg --command 'transport select hla_swd' --command 'set CPUTAPID #{CPUTAPID}' --file target/#{OOCD_TARGET}.cfg --command 'init' --command 'halt' --command 'reset init' --command 'stm32f1x unlock 0' --command 'reset init' --command 'flash protect 0 0 last off' --command 'reset init' --command 'stm32f1x options_write 0 SWWDG NORSTSTNDBY NORSTSTOP' --command 'reset init' --command 'stm32f1x mass_erase 0' --command 'shutdown'"
+      sh "#{OOCD} --file interface/#{OOCD_INTERFACE}.cfg --file target/#{OOCD_TARGET}.cfg --command 'init' --command 'reset init'  --command 'stm32f1x unlock 0' --command 'reset init' --command 'flash protect 0 0 last off' --command 'reset init' --command 'stm32f1x options_write 0 SWWDG NORSTSTNDBY NORSTSTOP' --command 'reset init' --command 'stm32f1x mass_erase 0' --command 'shutdown'"
     when "BMP"
       sh "#{GDB} --eval-command='target extended-remote #{BMP_PORT}' --eval-command='set confirm off' --eval-command='monitor swdp_scan' --eval-command='attach 1' --eval-command='monitor option erase' --eval-command='monitor erase_mass' --eval-command='kill' --eval-command='quit'"
   end
@@ -215,7 +213,7 @@ desc "flash bootloader using SWD"
 task :flash_bootloader => BOOTLOADER+".hex" do |t|
   case SWD_ADAPTER
     when "STLINKV2"
-      sh "#{OOCD} --file interface/#{OOCD_INTERFACE}.cfg --command 'transport select hla_swd' --command 'set CPUTAPID #{CPUTAPID}' --file target/#{OOCD_TARGET}.cfg --command 'init' --command 'halt' --command 'reset init' --command 'flash erase_sector 0 0 last' --command 'flash write_image erase #{t.source}' --command 'reset' --command 'shutdown'"
+      sh "#{OOCD} --file interface/#{OOCD_INTERFACE}.cfg --file target/#{OOCD_TARGET}.cfg --command 'init' --command 'reset init' --command 'flash erase_sector 0 0 last' --command 'flash write_image erase #{t.source}' --command 'reset' --command 'shutdown'"
     when "BMP"
       sh "#{GDB} --eval-command='target extended-remote #{BMP_PORT}' --eval-command='set confirm off' --eval-command='monitor swdp_scan' --eval-command='attach 1' --eval-command='monitor erase_mass' --eval-command='load' --eval-command='kill' --eval-command='quit' #{t.source}"
   end
@@ -225,7 +223,7 @@ desc "flash application using SWD"
 task :flash_application => APPLICATION+".hex" do |t|
   case SWD_ADAPTER
     when "STLINKV2"
-      sh "#{OOCD} --file interface/#{OOCD_INTERFACE}.cfg --command 'transport select hla_swd' --command 'set CPUTAPID #{CPUTAPID}' --file target/#{OOCD_TARGET}.cfg --command 'adapter speed 100' --command 'init' --command 'halt' --command 'reset init' --command 'flash write_image erase #{t.source}' --command 'reset' --command 'shutdown'"
+      sh "#{OOCD} --file interface/#{OOCD_INTERFACE}.cfg --file target/#{OOCD_TARGET}.cfg --command 'init' --command 'reset init' --command 'flash write_image erase #{t.source}' --command 'reset' --command 'shutdown'"
     when "BMP"
       sh "#{GDB} --eval-command='target extended-remote #{BMP_PORT}' --eval-command='set confirm off' --eval-command='monitor swdp_scan' --eval-command='attach 1' --eval-command='load' --eval-command='kill' --eval-command='quit' #{t.source}"
   end
@@ -237,7 +235,7 @@ task :debug => APPLICATION+".elf" do |t|
   case SWD_ADAPTER
     when "STLINKV2"
       # for GDB to work with openOCD the firmware needs to be reloaded
-      exec("#{GDB} --eval-command='target remote | #{OOCD} --file interface/#{OOCD_INTERFACE}.cfg --command \"transport select hla_swd\" --command \"set CPUTAPID #{CPUTAPID}\" --file target/#{OOCD_TARGET}.cfg --command \"gdb_port pipe; log_output /dev/null; init\"' #{t.source}")
+      exec("#{GDB} --eval-command='target remote | #{OOCD} --file interface/#{OOCD_INTERFACE}.cfg --file target/#{OOCD_TARGET}.cfg --command \"gdb_port pipe; log_output /dev/null; init\"' --eval-command='monitor reset halt' --eval-command='load' --eval-command='monitor reset init' #{t.source}")
     when "BMP"
       exec("#{GDB} --eval-command='target extended-remote #{BMP_PORT}' --eval-command='monitor version' --eval-command='monitor swdp_scan' --eval-command='attach 1' #{t.source}")
   end
@@ -249,7 +247,7 @@ task :debug_bootloader => BOOTLOADER+".elf" do |t|
   case SWD_ADAPTER
     when "STLINKV2"
       # for GDB to work with openOCD the firmware needs to be reloaded
-      exec("#{GDB} --eval-command='target remote | #{OOCD} --file interface/#{OOCD_INTERFACE}.cfg --command \"transport select hla_swd\" --command \"set CPUTAPID #{CPUTAPID}\" --file target/#{OOCD_TARGET}.cfg --command \"gdb_port pipe; log_output /dev/null; init\"' --eval-command='monitor reset init' #{t.source}")
+      exec("#{GDB} --eval-command='target remote | #{OOCD} --file interface/#{OOCD_INTERFACE}.cfg --file target/#{OOCD_TARGET}.cfg --command \"gdb_port pipe; log_output /dev/null; init\"' --eval-command='monitor reset halt' --eval-command='load' --eval-command='monitor reset init' #{t.source}")
     when "BMP"
       exec("#{GDB} --eval-command='target extended-remote #{BMP_PORT}' --eval-command='monitor version' --eval-command='monitor swdp_scan' --eval-command='attach 1' #{t.source}")
   end

application.c

@@ -1,7 +1,20 @@
-/** STM32F1 application example
+/* This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+/** dachboden front panel access control
  *  @file
  *  @author King Kévin <kingkevin@cuvoodoo.info>
- *  @copyright SPDX-License-Identifier: GPL-3.0-or-later
  *  @date 2016-2020
  */
 
@@ -24,16 +37,17 @@
 #include <libopencm3/stm32/dbgmcu.h> // debug utilities
 #include <libopencm3/stm32/desig.h> // design utilities
 #include <libopencm3/stm32/flash.h> // flash utilities
+#include <libopencm3/stm32/f1/bkp.h> // backup domain utilities
+#include <libopencm3/stm32/timer.h> // timer utilities
 
 /* own libraries */
 #include "global.h" // board definitions
 #include "print.h" // printing utilities
-#if !defined(STLINKV2)
 #include "uart.h" // USART utilities
-#endif
 #include "usb_cdcacm.h" // USB CDC ACM utilities
 #include "terminal.h" // handle the terminal interface
 #include "menu.h" // menu utilities
+#include "led_ws2812b.h" // WS2812B RGB LED control
 
 /** watchdog period in ms */
 #define WATCHDOG_PERIOD 10000
@@ -41,16 +55,12 @@
 /** set to 0 if the RTC is reset when the board is powered on, only indicates the uptime
  *  set to 1 if VBAT can keep the RTC running when the board is unpowered, indicating the date and time
  */
-#if defined(CORE_BOARD)
 #define RTC_DATE_TIME 1
-#else
-#define RTC_DATE_TIME 0
-#endif
 
 /** number of RTC ticks per second
  *  @note use integer divider of oscillator to keep second precision
  */
-#define RTC_TICKS_SECOND 4
+#define RTC_TICKS_SECOND 1
 
 #if defined(RTC_DATE_TIME) && RTC_DATE_TIME
 /** the start time from which to RTC ticks count
@@ -65,9 +75,82 @@ static time_t time_start = 0;
 /** @defgroup main_flags flag set in interrupts to be processed in main task
  *  @{
  */
-static volatile bool rtc_internal_tick_flag = false; /**< flag set when internal RTC ticked */
+volatile bool rtc_internal_tick_flag = false; /**< flag set when internal RTC ticked */
 /** @} */
 
+/** GPIO pin connected to relay, used to control button connection to panel */
+#define RELAY_PANEL_PIN PB6
+/** GPIO pin connected to relay, used to simulate button press */
+#define RELAY_BUTTON_PIN PB7
+/** GPIO for button 1 */
+#define BUTTON1_PIN PB9
+/** GPIO for button 2 */
+#define BUTTON2_PIN PB8
+
+/** which button has been pressed */
+volatile uint8_t button_pressed = 0;
+
+/** if we apply the opening policy */
+bool opening_apply = false;
+uint8_t pattern_length = 0;
+
+static struct opening_settings_t {
+	uint8_t days; /**< which days of the week it door access applies (bit 7 = Monday) */
+	uint16_t start_time; /**< at which minutes of the day to start */
+	uint16_t stop_time; /**< at which minutes of the day to stop */
+	uint8_t button_pattern[10]; /**< sequence of buttons to press to open the door */
+} opening_settings;
+
+/** timer to generate the ticks for the button LED animations */
+#define LED_ANIMATION_TIMER 2
+
+/** number of timer ticks passed, for the LED animation */
+static volatile uint8_t led_animation_ticks = 0;
+
+/** the button LED animation for the rust fade (duration in ticks, R, G, B) */
+static const uint8_t rust_animation[][4] = {
+	{0, 0, 0, 0},
+	{1, 0xb7 / 10 * 1, 0x41 / 10 * 1, 0x0e / 10 * 1},
+	{1, 0xb7 / 10 * 2, 0x41 / 10 * 2, 0x0e / 10 * 2},
+	{1, 0xb7 / 10 * 3, 0x41 / 10 * 3, 0x0e / 10 * 3},
+	{1, 0xb7 / 10 * 4, 0x41 / 10 * 4, 0x0e / 10 * 4},
+	{1, 0xb7 / 10 * 5, 0x41 / 10 * 5, 0x0e / 10 * 5},
+	{1, 0xb7 / 10 * 4, 0x41 / 10 * 4, 0x0e / 10 * 4},
+	{1, 0xb7 / 10 * 3, 0x41 / 10 * 3, 0x0e / 10 * 3},
+	{1, 0xb7 / 10 * 2, 0x41 / 10 * 2, 0x0e / 10 * 2},
+	{1, 0xb7 / 10 * 1, 0x41 / 10 * 1, 0x0e / 10 * 1},
+	{0, 0, 0, 0},
+};
+
+/** the button LED animation for the strobe (duration in ticks, R, G, B) */
+static const uint8_t strobe_animation[][4] = {
+	{0, 0, 0, 0},
+	{1, 0xff / 2, 0xff / 2, 0xff / 2},
+	{2, 0, 0, 0},
+	{1, 0xff / 2, 0xff / 2, 0xff / 2},
+	{0, 0, 0, 0},
+};
+
+/** save current opening_settings into SRAM */
+static void save_opening_settings(void)
+{
+	BKP_DR1 = 0; // invalid saved settings
+	BKP_DR2 = opening_settings.days & 0x7f;
+	BKP_DR3 = opening_settings.start_time;
+	BKP_DR4 = opening_settings.stop_time;
+	BKP_DR5 = opening_settings.button_pattern[0];
+	BKP_DR6 = opening_settings.button_pattern[1];
+	BKP_DR7 = opening_settings.button_pattern[2];
+	BKP_DR8 = opening_settings.button_pattern[3];
+	BKP_DR9 = opening_settings.button_pattern[4];
+	BKP_DR10 = opening_settings.button_pattern[5];
+	BKP_DR11 = opening_settings.button_pattern[6];
+	BKP_DR12 = opening_settings.button_pattern[7];
+	BKP_DR13 = opening_settings.button_pattern[8];
+	BKP_DR14 = opening_settings.button_pattern[9];
+	BKP_DR1 = 0x4223; //validate saved setting
+}
+
 size_t putc(char c)
 {
 	size_t length = 0; // number of characters printed
@@ -120,7 +203,175 @@ static void command_reset(void* argument);
 /** switch to DFU bootloader
  *  @param[in] argument no argument required
  */
-static void command_bootloader(void* argument);
+static void command_bootloader_dfu(void* argument);
+
+/** switch to system memory / embedded USART bootloader
+ *  @param[in] argument no argument required
+ */
+static void command_bootloader_embedded(void* argument);
+
+/** show/set on which days the access policy applies
+ *  @param[in] argument 7x0/1 to enable day of the week, starting with Monday (optional)
+ */
+static void command_days(void* argument)
+{
+	const char* days = (char*)argument; // argument is optional days
+	if (NULL != argument) { // days are provided, parse and save them
+		bool valid = (7 == strlen(days)); // verify input string
+		for (uint8_t day = 0; day < 7 && valid; day++) {
+			if (days[day] != '0' && days[day] != '1') {
+				valid = false;
+			}
+		}
+		if (valid) { // save provided settings
+			// parse new days
+			opening_settings.days = 0;
+			for (uint8_t day = 0; day < 7; day++) {
+				if ('1' == days[day]) {
+					opening_settings.days |= (1 << (6 - day));
+				}
+			}
+			save_opening_settings(); // save days
+			puts("days saved\n");
+		} else {
+			puts("provide exactly 7 times 0 (off) or 1 (on). 1st digit for Monday, 7th digit for Sunday\n");
+		}
+	}
+	// display current days
+	printf("opening days: %07b\n", opening_settings.days);
+	const char* day_names[] = {"Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"};
+	for (uint8_t day = 0; day < LENGTH(day_names); day++) {
+		printf("- %s: %s\n", day_names[day], (opening_settings.days & (1 << (6 - day))) ? "on" : "off");
+	}
+}
+
+/** show/set on which time the access policy starts applying
+ *  @param[in] argument string with time of day, optional
+ */
+static void command_start(void* argument)
+{
+	const char* time = (char*)argument; // argument is optional time
+	if (NULL != argument) { // days are provided, parse and save them
+		bool valid = (5 == strlen(time)); // verify input string
+		if (!(valid && isdigit((int8_t)time[0]) && isdigit((int8_t)time[1]) && ':' == time[2] && isdigit((int8_t)time[3]) && isdigit((int8_t)time[4]))) {
+			valid = false;
+		}
+		if (valid) { // save provided settings
+			opening_settings.start_time = 0;
+			opening_settings.start_time += (time[4] - '0') * 1;
+			opening_settings.start_time += (time[3] - '0') * 10;
+			opening_settings.start_time += (time[1] - '0') * 60;
+			opening_settings.start_time += (time[0] - '0') * 600;
+			save_opening_settings(); // save days
+			puts("start time saved\n");
+		} else {
+			puts("provide time in HH:MM format\n");
+		}
+	}
+	printf("start time: %02u:%02u\n", opening_settings.start_time / 60, opening_settings.start_time % 60);
+}
+
+/** show/set on which time the access policy stops applying
+ *  @param[in] argument string with time of day, optional
+ */
+static void command_stop(void* argument)
+{
+	const char* time = (char*)argument; // argument is optional time
+	if (NULL != argument) { // days are provided, parse and save them
+		bool valid = (5 == strlen(time)); // verify input string
+		if (!(valid && isdigit((int8_t)time[0]) && isdigit((int8_t)time[1]) && ':' == time[2] && isdigit((int8_t)time[3]) && isdigit((int8_t)time[4]))) {
+			valid = false;
+		}
+		if (valid) { // save provided settings
+			opening_settings.stop_time = 0;
+			opening_settings.stop_time += (time[4] - '0') * 1;
+			opening_settings.stop_time += (time[3] - '0') * 10;
+			opening_settings.stop_time += (time[1] - '0') * 60;
+			opening_settings.stop_time += (time[0] - '0') * 600;
+			save_opening_settings(); // save days
+			puts("stop time saved\n");
+		} else {
+			puts("provide time in HH:MM format\n");
+		}
+	}
+	printf("stop time: %02u:%02u\n", opening_settings.stop_time / 60, opening_settings.stop_time % 60);
+}
+
+/** open door by simulating button press
+ *  @param[in] argument not used
+ */
+static void command_open(void* argument)
+{
+	(void)argument; // we won't use the argument
+	gpio_set(GPIO_PORT(RELAY_PANEL_PIN), GPIO_PIN(RELAY_PANEL_PIN)); // set high to activate relay and take control over the button
+	gpio_set(GPIO_PORT(RELAY_BUTTON_PIN), GPIO_PIN(RELAY_BUTTON_PIN)); // set high to activate relay an simulate button press
+	sleep_ms(1000); // hold button a bit
+	gpio_clear(GPIO_PORT(RELAY_BUTTON_PIN), GPIO_PIN(RELAY_BUTTON_PIN)); // set low to deactivate relay and release button
+	if (!opening_apply) {
+		gpio_clear(GPIO_PORT(RELAY_PANEL_PIN), GPIO_PIN(RELAY_PANEL_PIN)); // set low to deactivate relay and git control back to button
+	}
+}
+
+/** show/set button pattern
+ *  @param[in] argument sequence of 1/2
+ */
+static void command_pattern(void* argument)
+{
+	const char* pattern = (char*)argument; // argument is optional pattern
+	if (NULL != argument) { // pattern provided
+		bool valid = (LENGTH(opening_settings.button_pattern) >= strlen(pattern)); // verify input string
+		for (uint8_t i = 0; i < strlen(pattern) && valid; i++) {
+			if ('1' != pattern[i] && '2' != pattern[i]) {
+				valid = false;
+			}
+		}
+		if (valid) { // save provided settings
+			// reset pattern
+			for (uint8_t i = 0; i < LENGTH(opening_settings.button_pattern); i++) {
+				opening_settings.button_pattern[i] = 0;
+			}
+			// save new pattern
+			for (uint8_t i = 0; i < strlen(pattern); i++) {
+				opening_settings.button_pattern[i] = pattern[i] - '0';
+			}
+			save_opening_settings(); // save days
+			puts("button sequence saved\n");
+		} else {
+			printf("provide buttons sequence of up to %u 1 or 2\n", LENGTH(opening_settings.button_pattern));
+		}
+		for (pattern_length = 0; pattern_length < LENGTH(opening_settings.button_pattern) && opening_settings.button_pattern[pattern_length]; pattern_length++);
+	}
+	if (0 == opening_settings.button_pattern[0]) {
+		puts("no button sequence set\n");
+	} else {
+		puts("button sequence: ");
+		for (uint8_t i = 0; i < LENGTH(opening_settings.button_pattern) && opening_settings.button_pattern[i]; i++) {
+			putc(opening_settings.button_pattern[i] + '0');
+		}
+		putc('\n');
+	}
+}
+
+/** test LEDs
+ *  @param[in] argument "on" or "off"
+ */
+static void command_led(void* argument)
+{
+	const char* onoff  = (char*)argument; // if it should be switched on or off
+	if (NULL == onoff || 0 == strlen(onoff)) {
+		puts("say if the LEDs should be switched on or off\n");
+	} else if (0 == strcmp(onoff, "on")) {
+		for (uint8_t led = 0; led < LED_WS2812B_LEDS; led++) {
+			led_ws2812b_set_rgb(led, 0x20, 0x20 , 0x20);
+		}
+	} else if (0 == strcmp(onoff, "off")) {
+		for (uint8_t led = 0; led < LED_WS2812B_LEDS; led++) {
+			led_ws2812b_set_rgb(led, 0, 0 , 0);
+		}
+	} else {
+		printf("unknown argument %s\n", onoff);
+	}
+}