diff --git a/notebooks/raymond/test_espNow_send.ino b/notebooks/raymond/test_espNow_send.ino
new file mode 100644
index 0000000000000000000000000000000000000000..f5d56b7a8fc06cc2de4c81614712a84f84f76a3a
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+++ b/notebooks/raymond/test_espNow_send.ino
@@ -0,0 +1,233 @@
+/*********
+ Rui Santos
+ Complete project details at https://RandomNerdTutorials.com/esp-now-one-to-many-esp32-esp8266/
+
+ Permission is hereby granted, free of charge, to any person obtaining a copy
+ of this software and associated documentation files.
+
+ The above copyright notice and this permission notice shall be included in all
+ copies or substantial portions of the Software.
+*********/
+
+#include <esp_now.h>
+#include <WiFi.h>
+
+#define TdsSensorPin 4
+#define VREF 3.3 // analog reference voltage(Volt) of the ADC
+#define SCOUNT 50 // sum of sample point
+
+#define pH_Sensor 5
+float phValue = 0;
+
+#define temp_sensor 6
+
+int tds_buf[SCOUNT]; // store the analog value in the array, read from ADC
+int tds_buf_temp[SCOUNT];
+int tds_buf_idx = 0;
+int copyIndex = 0;
+
+float avg_voltage_tds = 0;
+float tdsValue = 0;
+float temperature = 25; // current temperature for compensation
+
+unsigned long int avgValue; //Store the average value of the sensor feedback
+float b;
+int buf[10],temp;
+
+// REPLACE WITH YOUR ESP RECEIVER'S MAC ADDRESS
+uint8_t broadcastAddress1[] = {0x68, 0xB6, 0xB3, 0x52, 0x81, 0x1C};
+
+typedef struct test_struct {
+ float ph;
+ float tds;
+ float temp;
+} test_struct;
+
+test_struct test;
+
+esp_now_peer_info_t peerInfo;
+
+// callback when data is sent
+void OnDataSent(const uint8_t *mac_addr, esp_now_send_status_t status) {
+ char macStr[18];
+ Serial.print("Packet to: ");
+ // Copies the sender mac address to a string
+ snprintf(macStr, sizeof(macStr), "%02x:%02x:%02x:%02x:%02x:%02x",
+ mac_addr[0], mac_addr[1], mac_addr[2], mac_addr[3], mac_addr[4], mac_addr[5]);
+ Serial.print(macStr);
+ Serial.print(" send status:\t");
+ Serial.println(status == ESP_NOW_SEND_SUCCESS ? "Delivery Success" : "Delivery Fail");
+ Serial.println("");
+}
+
+void setup() {
+ Serial.begin(115200);
+ pinMode(TdsSensorPin,INPUT);
+ pinMode(pH_Sensor,INPUT);
+ pinMode(temp_sensor, INPUT);
+
+ WiFi.mode(WIFI_STA);
+
+ if (esp_now_init() != ESP_OK) {
+ Serial.println("Error initializing ESP-NOW");
+ return;
+ }
+
+ esp_now_register_send_cb(OnDataSent);
+
+ // register peer
+ peerInfo.channel = 0;
+ peerInfo.encrypt = false;
+ // register first peer
+ memcpy(peerInfo.peer_addr, broadcastAddress1, 6);
+ if (esp_now_add_peer(&peerInfo) != ESP_OK){
+ Serial.println("Failed to add peer");
+ return;
+ }
+}
+
+
+unsigned long loop_delay;
+float temp_sum;
+int temp_index = 1;
+float average_temp, temp_val, temp_pot;
+float real_temp, temp_cal;
+int temp_flag = 1;
+float average_tds, tds_analog, real_tds, tds_sum, old_tds;
+int tds_index = 1;
+int tds_flag = 0;
+static float delay_length = 30000;
+
+void loop() {
+
+ delay(10);
+ temp_index = 1;
+ tds_index = 1;
+ tds_sum = 0;
+ loop_delay = millis();
+ temp_sum = 0;
+
+ while(tds_index < 150){
+ tds_analog = analogRead(TdsSensorPin) * 3.3 / 4096;
+ tds_sum += tds_analog;
+ tds_index++;
+ }
+ average_tds = tds_sum / tds_index;
+ float compensationCoefficient = 1.0+0.02*(temperature-25.0);
+ //temperature compensation
+ float compensationVoltage=average_tds/compensationCoefficient;
+ //convert voltage value to tds value
+ tdsValue=(133.42*compensationVoltage*compensationVoltage*compensationVoltage - 255.86*compensationVoltage*compensationVoltage + 857.39*compensationVoltage)*0.5;
+ Serial.print("TDS Value:");
+ Serial.print(tdsValue,0);
+ Serial.println("ppm");
+
+
+ delay(10);
+ // pH value calculation
+ for(int i=0;i<10;i++) //Get 10 sample value from the sensor for smooth the value
+ {
+ buf[i]=analogRead(pH_Sensor);
+ delay(10);
+ }
+ for(int i=0;i<9;i++) //sort the analog from small to large
+ {
+ for(int j=i+1;j<10;j++)
+ {
+ if(buf[i]>buf[j])
+ {
+ temp=buf[i];
+ buf[i]=buf[j];
+ buf[j]=temp;
+ }
+ }
+ }
+ avgValue=0;
+
+ for(int i=2;i<8;i++) //take the average value of 6 center sample
+ avgValue+=buf[i];
+ float phValue=(float)avgValue*3.3/4095/6; //convert the analog into millivolt
+ phValue=3.5*phValue;
+
+
+ delay(10);
+ // Temp code
+ while(temp_index < 150){
+ temp_val = analogRead(temp_sensor) * 4.5 / 4096;
+ // Serial.println(temp_val);
+ temp_sum += temp_val;
+ temp_index++;
+ }
+
+ average_temp = temp_sum / temp_index;
+ if(temp_flag ==1){
+ temp_pot = (average_temp * 5110) / (4.5 - average_temp);
+ temp_cal = temp_pot - 2025;
+ temp_flag = 0;
+ }
+ temp_pot = (average_temp * 5110) / (4.5 - average_temp) - temp_cal;
+ real_temp = (temp_pot - 1718) / 4.167;
+
+
+ Serial.print("Temperature (F): ");
+ Serial.println(real_temp);
+
+ //TDS output
+
+
+ //pH output
+ Serial.print("pH Value:");
+ Serial.println(phValue);
+
+
+ // tdsValue = 1100;
+ test.ph = phValue;
+ test.tds = tdsValue;
+ test.temp = real_temp;
+
+ esp_err_t result = esp_now_send(0, (uint8_t *) &test, sizeof(test_struct));
+
+ if (result == ESP_OK) {
+ Serial.println("Sent with success");
+ }
+ else {
+ Serial.println("Error sending the data");
+ }
+
+
+
+
+ if (phValue < 7.2) {
+ Serial.println("pH Low, dispensing basic chemical");
+ }
+
+ if (phValue > 7.8) {
+ Serial.println("pH High, dispensing acidic chemical");
+ }
+
+ if (tds_flag == 1) {
+ if (old_tds > tdsValue+25) {
+ tds_flag = 0;
+ Serial.println("Chlorine helped lower TDS value.");
+ } else {
+ Serial.println("Chlorine did not change TDS value. Please filter your water.");
+ tds_flag = 0;
+ }
+ } else if (tdsValue > 1000) {
+ Serial.println("TDS High, dispensing chlorine.");
+
+ old_tds = tdsValue;
+ tds_flag = 1;
+ } else {
+ tds_flag = 0;
+ }
+
+ if (72 < real_temp && real_temp < 76) {
+ Serial.println("Temperature is within the correct range.");
+ } else {
+ Serial.println("Temperature is not within the correct range.");
+ }
+ while(millis() - loop_delay < delay_length){
+
+ }
+}
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