basic state machine for app logic

CMakeLists.txt

     src/lcd.c
     src/text.c
     src/image.c
+    src/state.c
 
     ${CMAKE_CURRENT_BINARY_DIR}/fatfs/ff.c
     ${CMAKE_CURRENT_BINARY_DIR}/fatfs/ffunicode.c

include/ble.h

 };
 
 void ble_init(void);
+bool ble_is_ready(void);
 void ble_scan(enum ble_scan_mode mode);
 int ble_get_scan_results(struct ble_scan_result *buf, uint len);
 

include/state.h

+/*
+ * state.h
+ *
+ * Copyright (c) 2023 Thomas Buck (thomas@xythobuz.de)
+ *
+ * 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.
+ *
+ * See <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __STATE_H__
+#define __STATE_H__
+
+enum system_state {
+    STATE_INIT = 0,
+    STATE_SCAN,
+};
+
+void state_switch(enum system_state next);
+void state_run(void);
+
+#endif // __STATE_H__

src/ble.c

 }
 
 void ble_init(void) {
+    cyw43_thread_enter();
+
     for (uint i = 0; i < BLE_MAX_SCAN_RESULTS; i++) {
         scans[i].set = false;
     }
+    state = TC_OFF;
+
+    cyw43_thread_exit();
 
     l2cap_init();
     sm_init();
     hci_power_control(HCI_POWER_ON);
 }
 
+bool ble_is_ready(void) {
+    cyw43_thread_enter();
+
+    bool v = (state != TC_OFF);
+
+    cyw43_thread_exit();
+    return v;
+}
+
 void ble_scan(enum ble_scan_mode mode) {
     cyw43_thread_enter();
 
     switch (mode) {
     case BLE_SCAN_OFF:
         debug("stopping BLE scan");
-        state = TC_IDLE;
         gap_stop_scan();
+        state = TC_IDLE;
         break;
 
     case BLE_SCAN_ON:

src/main.c

 #include "lcd.h"
 #include "text.h"
 #include "image.h"
+#include "state.h"
 
 int main(void) {
     // required for debug console
     debug("init done");
     lcd_set_backlight(0x8000);
 
+    // wait for BLE stack to be ready before using it
+    while (!ble_is_ready()) {
+        sleep_ms(10);
+    }
+
+    debug("starting app");
+    state_switch(STATE_SCAN);
+
     while (1) {
         watchdog_update();
 

src/state.c

+/*
+ * state.c
+ *
+ * Copyright (c) 2022 - 2023 Thomas Buck (thomas@xythobuz.de)
+ *
+ * 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.
+ *
+ * See <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdio.h>
+
+#include "config.h"
+#include "log.h"
+#include "buttons.h"
+#include "ble.h"
+#include "lcd.h"
+#include "text.h"
+#include "state.h"
+
+static enum system_state state = STATE_INIT;
+
+void state_switch(enum system_state next) {
+    if (state == next) {
+        return;
+    }
+
+    // clean up old state when leaving it
+    switch (state) {
+    case STATE_SCAN:
+        debug("leaving STATE_SCAN");
+        ble_scan(BLE_SCAN_OFF);
+        break;
+
+    default:
+        break;
+    }
+
+    // prepare new state on entering
+    switch (next) {
+    case STATE_SCAN:
+        debug("entering STATE_SCAN");
+        ble_scan(BLE_SCAN_ON);
+        break;
+
+    default:
+        break;
+    }
+
+    state = next;
+}
+
+void state_run(void) {
+    static struct text_font font = {
+        .fontname = "fixed_10x20",
+        .font = NULL,
+    };
+    if (font.font == NULL) {
+        text_prepare_font(&font);
+    }
+
+    struct text_conf text = {
+        .text = "",
+        .x = 0,
+        .y = 50,
+        .justify = false,
+        .alignment = MF_ALIGN_CENTER,
+        .width = 240,
+        .height = 240 - 80,
+        .margin = 2,
+        .fg = RGB_565(0xFF, 0xFF, 0xFF),
+        .bg = RGB_565(0x00, 0x00, 0x00),
+        .font = &font,
+    };
+
+    switch (state) {
+    case STATE_SCAN: {
+        struct ble_scan_result results[BLE_MAX_SCAN_RESULTS] = {0};
+        int n = ble_get_scan_results(results, BLE_MAX_SCAN_RESULTS);
+        if (n <= 0) {
+            text.text = "N\nO\nN\nE";
+            text_draw(&text);
+        } else {
+            char buff[1024] = {0};
+            uint pos = 0;
+
+            for (int i = 0; i < n; i++) {
+                pos += snprintf(buff + pos, sizeof(buff) - pos, "%s\n", results[i].name);
+            }
+
+            text.text = buff;
+            text_draw(&text);
+        }
+        break;
+    }
+
+    default:
+        debug("invalid main state %d", state);
+        state_switch(STATE_SCAN);
+        break;
+    }
+}