From f31106a47d7da479cd783737a67b08909b519a01 Mon Sep 17 00:00:00 2001
From: s3lph <s3lph@kabelsalat.ch>
Date: Fri, 27 Dec 2024 23:19:19 +0100
Subject: [PATCH] feat: fetch ntp servers from dhcp via a software dhcp
 implementation

---
 esp/platformio.ini |  3 +-
 esp/src/main.cpp   | 91 ++++++++++++++++++++++++++++++++++------------
 2 files changed, 69 insertions(+), 25 deletions(-)

diff --git a/esp/platformio.ini b/esp/platformio.ini
index 39bbc1a..4293149 100644
--- a/esp/platformio.ini
+++ b/esp/platformio.ini
@@ -16,5 +16,4 @@ upload_protocol = esptool
 lib_deps =
     adafruit/Adafruit NeoPixel@^1.11.0
     sstaub/NTP@^1.6
-;board_build.mcu = esp8266
-;board_build.f_cpu = 80000000L
\ No newline at end of file
+    https://git.kabelsalat.ch/s3lph/Arduino-Library-SoftDhcp.git
diff --git a/esp/src/main.cpp b/esp/src/main.cpp
index 589c7a4..334bda6 100644
--- a/esp/src/main.cpp
+++ b/esp/src/main.cpp
@@ -3,33 +3,75 @@
 #include <WiFiUdp.h>
 #include <NTP.h>
 #include <Adafruit_NeoPixel.h>
+#include <SoftDhcp.h>
+
+#define DHCP_TIME_SERVERS 4
 
 Adafruit_NeoPixel pixels(60, 5, NEO_GRB + NEO_KHZ800);
 
 uint16_t ADC_MAX = 900;
 uint16_t ADC_MIN = 250;
 uint8_t ADC_INVERT = 1;
-uint8_t BRIGHT_MIN = 50;
+uint8_t BRIGHT_MIN = 25;
 uint8_t BRIGHT_MAX = 255;
 
 const char *ssid     = put your ssid here;
 const char *password = put your psk here;
 
+SoftDhcp dhcp;
 WiFiUDP wifiUdp;
 NTP ntp(wifiUdp);
+bool ntpInitialized = false;
+
+IPAddress ntp_server;
+
+void setupNtp() {
+  Serial.print("IP: ");
+  Serial.println(dhcp.localIP());
+  Serial.print("NM: ");
+  Serial.println(dhcp.subnetMask());
+  Serial.print("GW: ");
+  Serial.println(dhcp.gatewayIP());
+  Serial.print("DNS1: ");
+  Serial.println(dhcp.dnsIP(0));
+  Serial.print("DNS2: ");
+  Serial.println(dhcp.dnsIP(1));
+  ntp.stop();
+  uint32_t ip;
+  ntp.ruleDST("CEST", Last, Sun, Mar, 2, 120); // last sunday in march 2:00, timetone +120min (+1 GMT + 1h summertime offset)
+  ntp.ruleSTD("CET", Last, Sun, Oct, 3, 60); // last sunday in october 3:00, timezone +60min (+1 GMT)
+  if (dhcp.getOption(DHCP_TIME_SERVERS, &ip, 4, 0) > 0) {
+    ntp_server = ip;
+    ntp.begin(ntp_server);
+    Serial.print("Starting NTP using ");
+    Serial.println(ntp_server.toString());
+  } else {
+    ntp.begin();
+    Serial.println("Starting NTP");
+  }
+  ntp.update();
+  ntpInitialized = true;
+}
+
+void expired() {
+  //Serial.println("DHCP lease expired, stopping NTP");
+  ntp.stop();
+  ntpInitialized = false;
+}
 
 void setup() {
   Serial.begin(115200);
+  dhcp.onLease(setupNtp);
+  dhcp.onExpire(expired);
+  dhcp.requestOption(DHCP_TIME_SERVERS);
+  dhcp.begin();
   WiFi.begin(ssid, password);
   while (WiFi.status() != WL_CONNECTED) {
     Serial.println("Connecting ...");
     delay(500);
   }
-  Serial.println("Connected");  
-  ntp.ruleDST("CEST", Last, Sun, Mar, 2, 120); // last sunday in march 2:00, timetone +120min (+1 GMT + 1h summertime offset)
-  ntp.ruleSTD("CET", Last, Sun, Oct, 3, 60); // last sunday in october 3:00, timezone +60min (+1 GMT)
-  ntp.begin();
-  Serial.println("start NTP");
+  Serial.println("Connected. Getting DHCP time info");
+  dhcp.update();
   pixels.begin();
 }
 
@@ -45,21 +87,24 @@ void loop() {
     bscale = 255 - bscale;
   }
   bscale = min(max(bscale, BRIGHT_MIN), BRIGHT_MAX);
-  Serial.print(brightness);
-  Serial.print(" -> ");
-  Serial.println(bscale);
-  ntp.update();
-  Serial.println(ntp.formattedTime("%T"));
-  uint8_t h = sixtyToPixel((ntp.hours() % 12) * 5 + (ntp.minutes() / 12));
-  uint8_t hl = sixtyToPixel((ntp.hours() % 12) * 5 + (ntp.minutes() / 12) - 1);
-  uint8_t hr = sixtyToPixel((ntp.hours() % 12) * 5 + (ntp.minutes() / 12) + 1);
-  uint8_t m = sixtyToPixel(ntp.minutes());
-  uint8_t s = sixtyToPixel(ntp.seconds());
-  pixels.clear();
-  pixels.setPixelColor(hl, pixels.getPixelColor(hl) | (bscale << 16));
-  pixels.setPixelColor(h, pixels.getPixelColor(h) | (bscale << 16));
-  pixels.setPixelColor(hr, pixels.getPixelColor(hr) | (bscale << 16));
-  pixels.setPixelColor(m, pixels.getPixelColor(m) | (bscale << 8) | (bscale >> 2));
-  pixels.setPixelColor(s, pixels.getPixelColor(s) | bscale);
-  pixels.show();
+  //Serial.print(brightness);
+  //Serial.print(" -> ");
+  //Serial.println(bscale);
+  dhcp.update();
+  if (ntpInitialized) {
+    ntp.update();
+    Serial.println(ntp.formattedTime("%T"));
+    uint8_t h = sixtyToPixel((ntp.hours() % 12) * 5 + (ntp.minutes() / 12));
+    uint8_t hl = sixtyToPixel((ntp.hours() % 12) * 5 + (ntp.minutes() / 12) - 1);
+    uint8_t hr = sixtyToPixel((ntp.hours() % 12) * 5 + (ntp.minutes() / 12) + 1);
+    uint8_t m = sixtyToPixel(ntp.minutes());
+    uint8_t s = sixtyToPixel(ntp.seconds());
+    pixels.clear();
+    pixels.setPixelColor(hl, pixels.getPixelColor(hl) | (bscale << 16));
+    pixels.setPixelColor(h, pixels.getPixelColor(h) | (bscale << 16));
+    pixels.setPixelColor(hr, pixels.getPixelColor(hr) | (bscale << 16));
+    pixels.setPixelColor(m, pixels.getPixelColor(m) | (bscale << 8) | (bscale >> 2));
+    pixels.setPixelColor(s, pixels.getPixelColor(s) | bscale);
+    pixels.show();
+  }
 }