feat(firmware): add GPIO expander and keypad drivers

2026-07-02 23:32:27 +02:00
parent 5ed0412c67
commit 7b31618199
18 changed files with 992 additions and 19 deletions
@@ -0,0 +1,161 @@
+# Firmware Debug
+
+## Purpose
+
+This document describes the debugging methods used during the development of the OpenParcelBox firmware.
+
+The objective is to provide simple diagnostic tools that work even when a debugger is unavailable.
+
+---
+
+# Debug Methods
+
+The firmware currently supports the following debugging methods:
+
+- UART console (`printf`)
+- On-board RGB LED
+- Zephyr Shell (when enabled)
+
+Additional methods may be added later:
+
+- Zigbee diagnostics
+- Home Assistant diagnostic entities
+- NFC diagnostics
+
+---
+
+# UART Console
+
+The UART console is the primary debugging interface during firmware development.
+
+Example:
+
+```c
+printf("Initialization completed.\n");
+printf("Key pressed: %c\n", key);
+```
+
+UART should be preferred whenever a serial connection is available.
+
+---
+
+# RGB LED Status Codes
+
+The onboard RGB LED is used to quickly identify the firmware state.
+
+## Startup
+
+| Color   | Meaning                             |
+| ------- | ----------------------------------- |
+| Red     | Firmware initialization in progress |
+| Green   | Firmware initialized successfully   |
+| Magenta | Initialization failed               |
+
+---
+
+## Runtime
+
+| Color   | Meaning                   |
+| ------- | ------------------------- |
+| Green   | Idle / Ready              |
+| Blue    | User interaction detected |
+| Yellow  | Warning                   |
+| Cyan    | Reserved                  |
+| White   | Reserved                  |
+| Red     | Reserved                  |
+| Magenta | Fatal error               |
+
+---
+
+# Current Diagnostic Sequence
+
+Current startup sequence:
+
+1. Initialize RGB LED
+2. Turn LED Red
+3. Initialize peripherals
+4. If initialization fails:
+   - Turn LED Magenta
+   - Stop execution
+5. Turn LED Green
+6. Start main application loop
+
+---
+
+# UART Examples
+
+Keypad:
+
+```text
+Key pressed: 1
+Key pressed: 5
+Key pressed: #
+```
+
+Future lock module:
+
+```text
+Opening lock...
+Lock opened.
+```
+
+Future NFC module:
+
+```text
+NFC tag detected.
+UID: xx xx xx xx
+```
+
+---
+
+# Zephyr Shell
+
+The Zephyr Shell is enabled during development.
+
+Typical commands:
+
+```text
+uart:~$ i2c scan i2c@40004000
+```
+
+This allows verification of:
+
+- I²C devices
+- GPIO configuration
+- Driver availability
+
+The shell is intended for development only and may be disabled in production builds.
+
+---
+
+# Production Firmware
+
+The production firmware should not rely on the UART console.
+
+Diagnostics should instead use:
+
+- RGB LED
+- Zigbee diagnostic messages
+- Home Assistant entities
+- Error reporting through the application
+
+---
+
+# Future Improvements
+
+Planned debugging features:
+
+- Configurable log levels
+- Persistent error codes
+- Diagnostic mode
+- Self-test during startup
+- Hardware validation report
+- Watchdog diagnostics
+
+---
+
+# Notes
+
+Debugging features should remain lightweight to minimize firmware size and power consumption.
+
+Development-only diagnostics should be removable without affecting the application logic.
@@ -0,0 +1,82 @@
+# GPIO Expander
+
+## Purpose
+
+This module provides a hardware abstraction layer (HAL) for the external GPIO expander.
+
+The current implementation targets the PCF8574 connected over the I²C bus. Other GPIO expanders (PCF8575, MCP23017, etc.) can later be supported by modifying only this module.
+
+All higher-level modules (keypad, lock, etc.) must use this API instead of directly accessing the I²C bus.
+
+---
+
+## Development Hardware
+
+- Seeed Studio XIAO nRF52840
+- PCF8574
+- I²C address: `0x20`
+
+---
+
+## Public API
+
+```c
+int gpio_expander_init(void);
+
+int gpio_expander_read_port(uint8_t *value);
+
+int gpio_expander_write_port(uint8_t value);
+
+bool gpio_expander_read_pin(uint8_t pin);
+
+int gpio_expander_write_pin(uint8_t pin, bool state);
+
+int gpio_expander_update_port(uint8_t mask, uint8_t value);
+```
+
+---
+
+## Design Goals
+
+- Hide the hardware implementation.
+- Avoid direct I²C access from application modules.
+- Allow replacing the GPIO expander without modifying the rest of the firmware.
+
+---
+
+## Current Implementation
+
+- PCF8574
+- 8 GPIO
+- Quasi-bidirectional outputs
+- I²C communication
+
+---
+
+## Future Improvements
+
+Possible future implementations:
+
+- PCF8575
+- MCP23008
+- MCP23017
+
+Only `gpio_expander.c` should require modifications.
+
+---
+
+## Used By
+
+- Keypad
+- Future lock module (if additional GPIO are required)
+- Future peripherals connected through an external GPIO expander
+
+---
+
+## Notes
+
+The PCF8574 uses quasi-bidirectional GPIOs.
+
+A pin must be written HIGH before it can be used as an input.
+
+This behavior is fully handled by this module and should remain transparent to higher-level drivers.
@@ -0,0 +1,80 @@
+# Keypad
+
+## Purpose
+
+This module manages the matrix keypad used by OpenParcelBox.
+
+The current implementation targets the development hardware based on a Freenove 4x4 keypad connected through a PCF8574 I²C GPIO expander.
+
+The production hardware will use a custom 2x6 keypad. The scanning algorithm will remain identical. Only the hardware mapping and key table will change.
+
+---
+
+## Development Hardware
+
+- Seeed Studio XIAO nRF52840
+- Freenove 4x4 Matrix Keypad
+- PCF8574 GPIO Expander
+- I²C address: `0x20`
+
+---
+
+## Wiring
+
+| PCF8574 | Function |
+| ------- | -------- |
+| P0      | Row 1    |
+| P1      | Row 2    |
+| P2      | Row 3    |
+| P3      | Row 4    |
+| P4      | Column 1 |
+| P5      | Column 2 |
+| P6      | Column 3 |
+| P7      | Column 4 |
+
+---
+
+## Key Mapping
+
+|       | Col 1 | Col 2 | Col 3 | Col 4 |
+| ----- | ----- | ----- | ----- | ----- |
+| Row 1 | 1     | 2     | 3     | A     |
+| Row 2 | 4     | 5     | 6     | B     |
+| Row 3 | 7     | 8     | 9     | C     |
+| Row 4 | *     | 0     | #     | D     |
+
+---
+
+## Public API
+
+```c
+int keypad_init(void);
+
+char keypad_get_key(void);
+```
+
+`keypad_get_key()` returns:
+
+- `0` if no key is available.
+- The ASCII value of the pressed key.
+
+Each key press is reported only once.
+
+---
+
+## Current Features
+
+- Matrix scanning
+- Debounce
+- Single key detection
+- Anti-repeat
+- Modular GPIO Expander interface
+
+---
+
+## Planned Improvements
+
+- Support for the production 2x6 keypad.
+- Configurable key mapping.
+- Optional audible feedback handled by the buzzer module.
+- Unit tests.
@@ -6,5 +6,7 @@ project(OpenParcelBox)

 target_sources(app PRIVATE
    src/main.c
-    src/board.c
+    src/led.c
+    src/gpio_expander.c
+    src/keypad.c
 )
@@ -0,0 +1,11 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * OpenParcelBox
+ *
+ * Development board configuration.
+ */
+
+&i2c1 {
+    status = "okay";
+};
@@ -1,18 +1,52 @@
-# Contraintes application
+# Firmware Constraints

 ## Technologies

- Développement avec Flutter.
- Compatibilité Android prioritaire.
- Compatibilité iOS souhaitée mais non bloquante pour la V1.
+- Development with Zephyr RTOS.
+- Programming language: C17.
+- Target board: Seeed Studio XIAO nRF52840.
+- Build system: CMake + West.
+- All source code comments must be written in English.
+- The firmware must compile without warnings whenever possible.

-## Fonctionnement
+## Architecture

- Utilisation locale prioritaire.
- Interface simple pour les utilisateurs non techniques.
+- Modular architecture.
+- One module per hardware peripheral or functional block.
+- Hardware abstraction must be separated from business logic.
+- All GPIO assignments must be centralized in `board_config.h`.
+- Hardware initialization must be centralized in the board module.

-## Fonctionnalités
+## Hardware

- Gestion des accès.
- Gestion des codes.
- Consultation de l'état de la boîte.
+- Battery-powered operation.
+- Minimize power consumption whenever possible.
+- GPIO assignments must match the hardware documentation.
+- DeviceTree must be used for hardware configuration whenever possible.
+- I²C peripherals must use Zephyr drivers.
+
+## Features
+
+- Matrix keypad management.
+- Electronic lock control.
+- Lock state monitoring.
+- PWM buzzer control.
+- PCF8574 I/O expander support.
+- NFC support.
+- Zigbee communication.
+- Battery level monitoring.
+- LED status management.
+
+## Development Rules
+
+- Develop one hardware module at a time.
+- Each module must compile successfully before starting the next one.
+- Validate each hardware feature on the development board before integration.
+- Avoid unused source files.
+- Keep the project structure clean and scalable.
+
+## Documentation
+
+- Every public function must be documented.
+- Complex algorithms must include explanatory comments in English.
+- Keep the firmware synchronized with the project documentation.
@@ -1,10 +1,7 @@
 CONFIG_GPIO=y
 CONFIG_I2C=y
-CONFIG_PWM=y
-
-CONFIG_SERIAL=y
+CONFIG_I2C_SHELL=y
+CONFIG_SHELL=y
 CONFIG_CONSOLE=y
-
-CONFIG_LOG=y
-CONFIG_LOG_MODE_IMMEDIATE=y
-CONFIG_LOG_DEFAULT_LEVEL=3
+CONFIG_SERIAL=y
+CONFIG_UART_CONSOLE=y
@@ -0,0 +1,26 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * OpenParcelBox
+ * Copyright (c) 2026
+ *
+ * Board pin definitions.
+ */
+
+#ifndef BOARD_PINS_H
+#define BOARD_PINS_H
+
+#include <zephyr/devicetree.h>
+
+/* RGB LED */
+
+#define LED_RED_NODE DT_ALIAS(led0)
+#define LED_GREEN_NODE DT_ALIAS(led1)
+#define LED_BLUE_NODE DT_ALIAS(led2)
+
+/* GPIO Expander */
+
+#define GPIO_EXPANDER_I2C_NODE DT_NODELABEL(i2c1)
+#define GPIO_EXPANDER_ADDRESS 0x20
+
+#endif /* BOARD_PINS_H */
@@ -0,0 +1,99 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * OpenParcelBox
+ * Copyright (c) 2026
+ *
+ * GPIO expander abstraction layer.
+ *
+ * Current implementation:
+ *   PCF8574 connected on I2C.
+ */
+
+#include "gpio_expander.h"
+
+#include "board_pins.h"
+
+#include <zephyr/device.h>
+#include <zephyr/drivers/i2c.h>
+
+#include <stdbool.h>
+#include <stdint.h>
+
+/* --------------------------------------------------------------------------
+ * Static variables
+ * -------------------------------------------------------------------------- */
+
+static const struct device *i2c_dev = DEVICE_DT_GET(GPIO_EXPANDER_I2C_NODE);
+
+/*
+ * Current GPIO output state.
+ *
+ * The PCF8574 uses quasi-bidirectional GPIOs.
+ * Pins intended to be used as inputs must remain HIGH.
+ */
+static uint8_t gpio_state = 0xFF;
+
+/* --------------------------------------------------------------------------
+ * Public API
+ * -------------------------------------------------------------------------- */
+
+int gpio_expander_init(void) {
+  if (!device_is_ready(i2c_dev)) {
+    return -1;
+  }
+
+  gpio_state = 0xFF;
+
+  return gpio_expander_write_port(gpio_state);
+}
+
+int gpio_expander_read_port(uint8_t *value) {
+  if (value == NULL) {
+    return -1;
+  }
+
+  return i2c_read(i2c_dev, value, sizeof(*value), GPIO_EXPANDER_ADDRESS);
+}
+
+int gpio_expander_write_port(uint8_t value) {
+  gpio_state = value;
+
+  return i2c_write(i2c_dev, &gpio_state, sizeof(gpio_state),
+                   GPIO_EXPANDER_ADDRESS);
+}
+
+bool gpio_expander_read_pin(uint8_t pin) {
+  uint8_t value;
+
+  if (pin > 7U) {
+    return false;
+  }
+
+  if (gpio_expander_read_port(&value) != 0) {
+    return false;
+  }
+
+  return (value & (1U << pin)) != 0U;
+}
+
+int gpio_expander_write_pin(uint8_t pin, bool state) {
+  if (pin > 7U) {
+    return -1;
+  }
+
+  if (state) {
+    gpio_state |= (1U << pin);
+  } else {
+    gpio_state &= ~(1U << pin);
+  }
+
+  return gpio_expander_write_port(gpio_state);
+}
+
+int gpio_expander_update_port(uint8_t mask, uint8_t value) {
+  gpio_state &= ~mask;
+  gpio_state |= (value & mask);
+
+  return gpio_expander_write_port(gpio_state);
+}
@@ -0,0 +1,88 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * OpenParcelBox
+ * Copyright (c) 2026
+ *
+ * GPIO expander abstraction layer.
+ */
+
+#ifndef GPIO_EXPANDER_H
+#define GPIO_EXPANDER_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdbool.h>
+#include <stdint.h>
+
+/**
+ * @brief Initialize the GPIO expander.
+ *
+ * Initializes the external GPIO expander used by the firmware.
+ *
+ * @retval 0 Success.
+ * @retval <0 Initialization failed.
+ */
+int gpio_expander_init(void);
+
+/**
+ * @brief Read the complete GPIO port.
+ *
+ * @param[out] value Pointer receiving the GPIO state.
+ *
+ * @retval 0 Success.
+ * @retval <0 Read failed.
+ */
+int gpio_expander_read_port(uint8_t *value);
+
+/**
+ * @brief Write the complete GPIO port.
+ *
+ * @param value GPIO output state.
+ *
+ * @retval 0 Success.
+ * @retval <0 Write failed.
+ */
+int gpio_expander_write_port(uint8_t value);
+
+/**
+ * @brief Read a single GPIO pin.
+ *
+ * @param pin GPIO pin number.
+ *
+ * @retval true Pin is HIGH.
+ * @retval false Pin is LOW or an error occurred.
+ */
+bool gpio_expander_read_pin(uint8_t pin);
+
+/**
+ * @brief Write a single GPIO pin.
+ *
+ * @param pin GPIO pin number.
+ * @param state Desired pin state.
+ *
+ * @retval 0 Success.
+ * @retval <0 Write failed.
+ */
+int gpio_expander_write_pin(uint8_t pin, bool state);
+
+/**
+ * @brief Update selected GPIO pins.
+ *
+ * Only the bits specified by the mask are modified.
+ *
+ * @param mask GPIO selection mask.
+ * @param value New value for selected pins.
+ *
+ * @retval 0 Success.
+ * @retval <0 Write failed.
+ */
+int gpio_expander_update_port(uint8_t mask, uint8_t value);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GPIO_EXPANDER_H */
@@ -0,0 +1,120 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * OpenParcelBox
+ * Copyright (c) 2026
+ *
+ * Module:
+ *   Keypad driver
+ *
+ * Description:
+ *   Driver for the 4x4 matrix keypad used during development.
+ *
+ * Development hardware:
+ *   - Freenove 4x4 Matrix Keypad
+ *   - PCF8574 I2C GPIO Expander
+ *   - I2C address: 0x20
+ *
+ * Wiring:
+ *
+ *             Columns
+ *          C1  C2  C3  C4
+ * PCF8574  P4  P5  P6  P7
+ *
+ * Rows
+ * P0
+ * P1
+ * P2
+ * P3
+ *
+ * Future:
+ *   The production OpenParcelBox keypad (2x6) will reuse this driver.
+ *   Only the row/column mapping and key table will change.
+ */
+
+#include "keypad.h"
+
+#include "gpio_expander.h"
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#include <zephyr/kernel.h>
+
+#define KEYPAD_ROW_COUNT 4
+#define KEYPAD_COLUMN_COUNT 4
+
+#define KEYPAD_DEBOUNCE_MS 20
+
+static const uint8_t row_pins[KEYPAD_ROW_COUNT] = {0, 1, 2, 3};
+
+static const uint8_t column_pins[KEYPAD_COLUMN_COUNT] = {4, 5, 6, 7};
+
+static const char keymap[KEYPAD_ROW_COUNT][KEYPAD_COLUMN_COUNT] = {
+    {'1', '2', '3', 'A'},
+    {'4', '5', '6', 'B'},
+    {'7', '8', '9', 'C'},
+    {'*', '0', '#', 'D'}};
+
+static char last_key = 0;
+
+/**
+ * @brief Scan the keypad matrix.
+ *
+ * @return Detected ASCII key or 0.
+ */
+static char keypad_scan(void) {
+  uint8_t value;
+
+  for (uint8_t row = 0; row < KEYPAD_ROW_COUNT; row++) {
+
+    gpio_expander_write_port(0xFF);
+
+    gpio_expander_write_pin(row_pins[row], false);
+
+    if (gpio_expander_read_port(&value) != 0) {
+      continue;
+    }
+
+    for (uint8_t column = 0; column < KEYPAD_COLUMN_COUNT; column++) {
+
+      if ((value & (1U << column_pins[column])) == 0U) {
+
+        return keymap[row][column];
+      }
+    }
+  }
+
+  return 0;
+}
+
+int keypad_init(void) {
+  last_key = 0;
+
+  return gpio_expander_init();
+}
+
+char keypad_get_key(void) {
+  char key;
+
+  key = keypad_scan();
+
+  if (key == 0) {
+    last_key = 0;
+    return 0;
+  }
+
+  k_msleep(KEYPAD_DEBOUNCE_MS);
+
+  if (key != keypad_scan()) {
+    return 0;
+  }
+
+  if (key == last_key) {
+    return 0;
+  }
+
+  last_key = key;
+
+  return key;
+}
@@ -0,0 +1,40 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * OpenParcelBox
+ * Copyright (c) 2026
+ */
+
+#ifndef KEYPAD_H
+#define KEYPAD_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief Initialize the keypad driver.
+ *
+ * Initializes the GPIO expander and prepares the keypad driver.
+ *
+ * @retval 0 Success.
+ * @retval <0 Initialization failed.
+ */
+int keypad_init(void);
+
+/**
+ * @brief Read a key from the keypad.
+ *
+ * Performs a keypad scan and returns a single key press.
+ * The same key is returned only once until it is released.
+ *
+ * @return ASCII character corresponding to the pressed key.
+ * @return 0 if no key is available.
+ */
+char keypad_get_key(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* KEYPAD_H */
@@ -0,0 +1,82 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * OpenParcelBox
+ * Copyright (c) 2026
+ *
+ * RGB LED driver.
+ */
+
+#include "led.h"
+
+#include "board_pins.h"
+
+#include <stdbool.h>
+
+#include <zephyr/drivers/gpio.h>
+
+static const struct gpio_dt_spec led_red_gpio =
+    GPIO_DT_SPEC_GET(LED_RED_NODE, gpios);
+
+static const struct gpio_dt_spec led_green_gpio =
+    GPIO_DT_SPEC_GET(LED_GREEN_NODE, gpios);
+
+static const struct gpio_dt_spec led_blue_gpio =
+    GPIO_DT_SPEC_GET(LED_BLUE_NODE, gpios);
+
+/**
+ * @brief Set the RGB LED state.
+ *
+ * @param red   Red LED state.
+ * @param green Green LED state.
+ * @param blue  Blue LED state.
+ */
+static void led_set_rgb(bool red, bool green, bool blue) {
+  gpio_pin_set_dt(&led_red_gpio, red);
+  gpio_pin_set_dt(&led_green_gpio, green);
+  gpio_pin_set_dt(&led_blue_gpio, blue);
+}
+
+int led_init(void) {
+  int ret;
+
+  if (!gpio_is_ready_dt(&led_red_gpio) || !gpio_is_ready_dt(&led_green_gpio) ||
+      !gpio_is_ready_dt(&led_blue_gpio)) {
+    return -1;
+  }
+
+  ret = gpio_pin_configure_dt(&led_red_gpio, GPIO_OUTPUT_INACTIVE);
+  if (ret < 0) {
+    return ret;
+  }
+
+  ret = gpio_pin_configure_dt(&led_green_gpio, GPIO_OUTPUT_INACTIVE);
+  if (ret < 0) {
+    return ret;
+  }
+
+  ret = gpio_pin_configure_dt(&led_blue_gpio, GPIO_OUTPUT_INACTIVE);
+  if (ret < 0) {
+    return ret;
+  }
+
+  led_off();
+
+  return 0;
+}
+
+void led_off(void) { led_set_rgb(false, false, false); }
+
+void led_set_red(void) { led_set_rgb(true, false, false); }
+
+void led_set_green(void) { led_set_rgb(false, true, false); }
+
+void led_set_blue(void) { led_set_rgb(false, false, true); }
+
+void led_set_yellow(void) { led_set_rgb(true, true, false); }
+
+void led_set_cyan(void) { led_set_rgb(false, true, true); }
+
+void led_set_magenta(void) { led_set_rgb(true, false, true); }
+
+void led_set_white(void) { led_set_rgb(true, true, true); }
@@ -0,0 +1,71 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * OpenParcelBox
+ * Copyright (c) 2026
+ *
+ * RGB LED driver.
+ */
+
+#ifndef LED_H
+#define LED_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief Initialize the RGB LED driver.
+ *
+ * Configures the three onboard RGB LED GPIOs.
+ *
+ * @retval 0 Success.
+ * @retval <0 Initialization failed.
+ */
+int led_init(void);
+
+/**
+ * @brief Turn off the RGB LED.
+ */
+void led_off(void);
+
+/**
+ * @brief Turn the RGB LED red.
+ */
+void led_set_red(void);
+
+/**
+ * @brief Turn the RGB LED green.
+ */
+void led_set_green(void);
+
+/**
+ * @brief Turn the RGB LED blue.
+ */
+void led_set_blue(void);
+
+/**
+ * @brief Turn the RGB LED yellow.
+ */
+void led_set_yellow(void);
+
+/**
+ * @brief Turn the RGB LED cyan.
+ */
+void led_set_cyan(void);
+
+/**
+ * @brief Turn the RGB LED magenta.
+ */
+void led_set_magenta(void);
+
+/**
+ * @brief Turn the RGB LED white.
+ */
+void led_set_white(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* LED_H */
@@ -0,0 +1,80 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * OpenParcelBox
+ * Copyright (c) 2026
+ *
+ * Main firmware entry point.
+ *
+ * Current test:
+ *   - RGB LED
+ *   - GPIO Expander
+ *   - 4x4 Keypad
+ */
+
+#include "keypad.h"
+#include "led.h"
+
+#include <zephyr/kernel.h>
+
+#include <stdio.h>
+
+/* --------------------------------------------------------------------------
+ * Defines
+ * -------------------------------------------------------------------------- */
+
+#define MAIN_LOOP_DELAY_MS 20
+#define KEY_PRESS_LED_MS 100
+
+/* --------------------------------------------------------------------------
+ * Public API
+ * -------------------------------------------------------------------------- */
+
+int main(void) {
+  char key;
+
+  if (led_init() < 0) {
+    return 0;
+  }
+
+  led_set_red();
+  k_msleep(1000);
+
+  if (keypad_init() < 0) {
+    led_set_magenta();
+
+    while (1) {
+      k_msleep(1000);
+    }
+  }
+
+  led_set_green();
+
+  printf("\n");
+  printf("========================================\n");
+  printf("OpenParcelBox Firmware\n");
+  printf("Hardware Test: RGB LED + Keypad\n");
+  printf("========================================\n");
+
+  led_set_green();
+
+  while (1) {
+
+    key = keypad_get_key();
+
+    if (key != 0) {
+
+      printf("Key pressed: %c\n", key);
+
+      led_set_blue();
+
+      k_msleep(KEY_PRESS_LED_MS);
+
+      led_set_green();
+    }
+
+    k_msleep(MAIN_LOOP_DELAY_MS);
+  }
+
+  return 0;
+}