From 77ad4e849b58950e674648c0f81e96a6515a8573 Mon Sep 17 00:00:00 2001
From: Kristjan Komlosi <kristjan@piskot.si>
Date: Fri, 6 Feb 2026 00:04:32 +0100
Subject: [PATCH] client: demo sketch

---
 esp-demo/esp-demo.ino | 68 +++++++++++++++++++++++++++++++++----------
 1 file changed, 52 insertions(+), 16 deletions(-)

diff --git a/esp-demo/esp-demo.ino b/esp-demo/esp-demo.ino
index 578ad97..7f4c316 100644
--- a/esp-demo/esp-demo.ino
+++ b/esp-demo/esp-demo.ino
@@ -5,18 +5,18 @@
 #include <Hash.h>
 
 // ---- Configure these ----
-const char *WIFI_SSID = "YOUR_WIFI_SSID";
-const char *WIFI_PASS = "YOUR_WIFI_PASS";
+const char *WIFI_SSID = "seminardemo";
+const char *WIFI_PASS = "seminardemo";
 
-const char *MQTT_HOST = "192.168.1.10"; // broker address (use host running mosquitto)
+const char *MQTT_HOST = "192.168.1.16"; // broker address (use host running mosquitto)
 const uint16_t MQTT_PORT = 1883;
 const char *MQTT_USER = "testuser";     // from test/.env
 const char *MQTT_PASS = "testpass";     // from test/.env
-
+\
 const char *MQTT_TOPIC = "lambdaiot";   // main topic
 
 // GPIO
-const uint8_t ACTOR_PIN = D1; // digital output
+const uint8_t ACTOR_PIN = 14; // digital output
 
 // Publishing interval (ms)
 const unsigned long SENSOR_PUBLISH_INTERVAL = 5000;
@@ -73,18 +73,46 @@ String formatUuid(const uint8_t bytes[16]) {
   return String(buf);
 }
 
+bool parseHexBytes(const String &hex, uint8_t *out, size_t outLen) {
+  if (hex.length() < (int)(outLen * 2)) {
+    return false;
+  }
+  for (size_t i = 0; i < outLen; i++) {
+    char c1 = hex[i * 2];
+    char c2 = hex[i * 2 + 1];
+    auto hexVal = [](char c) -> int {
+      if (c >= '0' && c <= '9') return c - '0';
+      if (c >= 'a' && c <= 'f') return c - 'a' + 10;
+      if (c >= 'A' && c <= 'F') return c - 'A' + 10;
+      return -1;
+    };
+    int v1 = hexVal(c1);
+    int v2 = hexVal(c2);
+    if (v1 < 0 || v2 < 0) {
+      return false;
+    }
+    out[i] = (uint8_t)((v1 << 4) | v2);
+  }
+  return true;
+}
+
 String uuidV5(const uint8_t namespaceBytes[16], const String &name) {
   // SHA1(namespace + name)
-  SHA1Builder sha;
-  sha.begin();
-  sha.add(namespaceBytes, 16);
-  sha.add((const uint8_t *)name.c_str(), name.length());
-  sha.calculate();
-  uint8_t hash[20];
-  sha.getHash(hash);
+  size_t totalLen = 16 + name.length();
+  uint8_t *buf = (uint8_t *)malloc(totalLen);
+  if (!buf) {
+    return String("");
+  }
+  memcpy(buf, namespaceBytes, 16);
+  memcpy(buf + 16, name.c_str(), name.length());
+
+  String hashHex = sha1(buf, totalLen);
+  free(buf);
 
   uint8_t out[16];
-  memcpy(out, hash, 16);
+  if (!parseHexBytes(hashHex, out, sizeof(out))) {
+    return String("");
+  }
 
   // Set version (5) and variant (RFC 4122)
   out[6] = (out[6] & 0x0F) | 0x50;
@@ -96,7 +124,7 @@ String uuidV5(const uint8_t namespaceBytes[16], const String &name) {
 // ---- MQTT messaging ----
 
 void publishDiscovery() {
-  StaticJsonDocument<512> doc;
+  StaticJsonDocument<1024> doc;
   doc["mac_address"] = macAddress;
 
   JsonObject dev = doc.createNestedObject("device");
@@ -120,11 +148,16 @@ void publishDiscovery() {
   a0["type"] = "GPIO";
   a0["data_type_id"] = 1;
 
-  char buf[512];
+  char buf[1024];
   size_t n = serializeJson(doc, buf, sizeof(buf));
+  
+  Serial.println(n);
+  Serial.println(buf);
 
   String topic = String(MQTT_TOPIC) + "/discovery";
-  mqtt.publish(topic.c_str(), buf, n);
+  Serial.println(topic);
+  int result = mqtt.publish(topic.c_str(), buf, n);
+  Serial.println(result);
 }
 
 void publishSensorReading() {
@@ -234,6 +267,7 @@ void ensureMqtt() {
     String clientId = "esp-demo-" + String(ESP.getChipId());
     if (mqtt.connect(clientId.c_str(), MQTT_USER, MQTT_PASS)) {
       mqtt.subscribe(MQTT_TOPIC);
+      delay(1000);
       publishDiscovery();
     } else {
       delay(2000);
@@ -244,6 +278,7 @@ void ensureMqtt() {
 void setup() {
   pinMode(ACTOR_PIN, OUTPUT);
   digitalWrite(ACTOR_PIN, LOW);
+  Serial.begin(9600);
 
   WiFi.mode(WIFI_STA);
   WiFi.begin(WIFI_SSID, WIFI_PASS);
@@ -265,6 +300,7 @@ void setup() {
   sensorId = uuidV5(deviceNs, "sensor-0");
   actorId = uuidV5(deviceNs, "actor-0");
 
+  mqtt.setBufferSize(4096); // Otherwise discovery fails spectacularly
   mqtt.setServer(MQTT_HOST, MQTT_PORT);
   mqtt.setCallback(mqttCallback);