Water Quality Monitoring eith ESP32, pH, and TDS

Projects Programming
1

My code compiles fine but when i try to upload it, i get this error (I haven't started the calibration yet because of this). Does the problem lie in the code or my hardware set-up?

rst:0x7 (TG0WDT_SYS_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
13:50:56.881 -> configsip: 0, SPIWP:0xee
13:50:56.881 -> clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
13:50:56.881 -> mode:DIO, clock div:1
13:50:56.881 -> load:0x3fff0030,len:4916
13:50:56.881 -> load:0xd0012000,len:4109
13:50:56.881 -> ho 0 tail 9 room 7
13:50:56.881 -> load:0x20024340,len:2080833800
13:50:56.881 -> 1150 mmu set 00010000, pos 00010000
13:50:56.915 -> 1150 mmu set 00020000, pos 00020000
13:50:56.915 -> 1150 mmu set 00030000, pos 00030000
13:50:56.915 -> 1150 mmu set 00040000, pos 00040000
13:50:56.950 -> 1150 mmu set 00050000, pos 00050000
13:50:56.950 -> 1150 mmu set 00060000, pos 00060000
13:50:56.950 -> 1150 mmu set 00070000, pos 00070000
13:50:56.993 -> 1150 mmu set 00080000, pos 00080000
13:50:56.993 -> 1150 mmu set 00090000, pos 00090000
13:50:56.993 -> 1150 mmu set 000a0000, pos 000a0000
13:50:57.038 -> 1150 mmu set 000b0000, pos 000b0000
13:50:57.038 -> 1150 mmu set 000c0000, pos 000c0000
13:50:57.038 -> 1150 mmu set 000d0000, pos 000d0000
13:50:57.038 -> 1150 mmu set 000e0000, pos 000e0000
13:50:57.072 -> 1150 mmu set 000f0000, pos 000f0000
13:50:57.072 -> 1150 mmu set 00100000, pos 00100000
13:50:57.072 -> 1150 mmu set 00110000, pos 00110000
13:50:57.120 -> 1150 mmu set 00120000, pos 00120000
13:50:57.120 -> 1150 mmu set 00130000, pos 00130000
13:50:57.120 -> 1150 mmu set 00140000, pos 00140000
13:50:57.120 -> 1150 mmu set 00150000, pos 00150000
13:50:57.158 -> 1150 mmu set 00160000, pos 00160000
13:50:57.158 -> 1150 mmu set 00170000, pos 00170000
13:50:57.158 -> 1150 mmu set 00180000, pos 00180000
13:50:57.191 -> 1150 mmu set 00190000, pos 00190000
13:50:57.191 -> ets Jul 29 2019 12:21:46

Here is my code:

#include <Arduino.h>

// Pin definitions
#define PH_SENSOR_PIN 34    
#define TDS_SENSOR_PIN 35   

// Constants
const float VREF = 3.3;     // ESP32 analog reference voltage (3.3V) 
const int ADC_RESOLUTION = 4095; // dont change 

//y=mx+b
float phSlope = 0.0;      // change during calibration
float phIntercept = 0.0;  // change during calibration

//y=mx+b
float tdsSlope = 0.0;     // Slope (scaling factor)
float tdsIntercept = 0.0; // Intercept (offset)

// Global variables
float phValue = 0.0;        
float tdsValue = 0.0;        

void setup() {
    Serial.begin(115200);  

    // Initialize pins
    pinMode(PH_SENSOR_PIN, INPUT);
    pinMode(TDS_SENSOR_PIN, INPUT);
}

void loop() {
    // Small delay to stabilize ADC readings
    delay(10);
    
    // Read analog values
    int rawPh = analogRead(PH_SENSOR_PIN);
    delay(10);
    int rawTds = analogRead(TDS_SENSOR_PIN);
    
    // Convert to voltage
    float voltagePh = (rawPh / (float)ADC_RESOLUTION) * VREF;
    float voltageTds = (rawTds / (float)ADC_RESOLUTION) * VREF;
    
    // Calculate pH and TDS using linear equation
    phValue = phSlope * voltagePh + phIntercept;
    tdsValue = tdsSlope * voltageTds + tdsIntercept;
     
    phValue = max(phValue, 0.0f);   
    tdsValue = max(tdsValue, 0.0f);   
    
    // Print values
    Serial.print("pH: "); Serial.println(phValue);
    Serial.print("TDS: "); Serial.println(tdsValue);
    
     
    delay(1000);
}
2

try printing the raw values of voltagePh and voltageTds?
do they appear to be reasonable?

EDIT: does a simple program such as blink compile, link and run OK?
which particular ESP32 are you using?

EDIT2: if I run your code of post 1 on an ESP32 the serial monitor displays

pH: 0.00
TDS: 0.00
pH: 0.00
TDS: 0.00
pH: 0.00
TDS: 0.00
pH: 0.00
3

I am using the esp32 development module. My code actually works when I ask my friend with the same sensors to run it, but for this particular esp32 it keeps repeating that error. Would factory resetting solve the problem?

edit: even if i code a simple code to just output raw values, it would still show the same error.

4

which specific module? give a link? or a photo?
could be a faulty module?

5

sorry, this one. the 38 pin nodemcu-32

https://robocraze.com/products/esp32-development-board?

6

no idea what is wrong
try a different USB cable?
does your ESP32 work when plugged into you friend's PC?

7

nope, my code only works on his esp32/ other esp32. i think the problem lies with my esp32