[Design real time temperature monitoring]

On 4/13/2020 at 3:11 PM, electrical211 said:

Hello everyone

I am new here for the guidance from experts. Actually, I am making a project that will take input from heat sensor and pass to the PIC micro-controller. I am using TFT display MLT028Q40-5 with controller through driver and this is working perfectly. I need help with the data to import from temperature sensor NTC. can any expert help me to solve the problem. I can provide more details if required. 

Looking forward for valuable Answers. Thank you so much.  

Continued to the previous question. can you please also help me to find best way of PCB design? Thank you again. 

ADC_GetConversion(adc_channel_t channel): This routine is used to select desired channel for conversion and to get the analog to digital converted value.

 

CODE:

----------------------------------------------------

 

#include "mcc_generated_files/mcc.h"
#include "lcd.h"
#include "stdio.h"

/*
                         Main application
 */

// This function creates seconds delay. 
// The argument specifies the delay time in seconds
void Delay_Seconds(unsigned char z)
{
    unsigned char x,y;
    for (y = 0; y < z; y++)
    {
        for (x = 0; x < 100; x++)__delay_ms(10);
    }
}

//**************Declare Global Variables**************************************
uint16_t convertedValue = 0;
float  voltage ;
char Buffer[20];

void main(void)
{
    // Initialize the device
    SYSTEM_Initialize();
    // initialize the LCD
    LCD_Initialize();

      
     LCDPutCmd(LCD_CURSOR_OFF);  //LCD Cursor off
     LCDPutStr("ADC with MCC");  //Display String "ADC with MCC"
     LCDGoto(0,1);               //Go to second line
     LCDPutStr("Turn POT on AN0");  //Display String "Turn Potentiometer on AN0"
     Delay_Seconds(2);    // 2 seconds delay
     DisplayClr();        // Clear the display
     
          
    while (1)
    {
        convertedValue = 0;
     
      ADC_StartConversion(channel_AN0);
      while(!ADC_IsConversionDone());
        convertedValue = ADC_GetConversionResult(); 
       
       voltage = (convertedValue * 5.0)/1023; // convert ADC count into voltage
       LCDPutStr("Voltage = "); //Display "Voltage" on the screen
       sprintf(Buffer, " %.3g", voltage ); // Convert voltage to string, rounded to 3 decimal points number
       LCDPutStr(Buffer); //Display the Voltage on the screen
       LCDPutStr("     "); // Clear after comma 
       LCDGoto(0,0);               //Go to first line
     
     }
}
/**
 End of File
*/

 

--------------------------------------------------

Comment:

Instead of 

voltage = (convertedValue * 5.0)/1023; 

you can add your conversion equation of NTC sensor.

such as

temperature=B/(ln(convertedValue/r¤))

Here the convertedValue is the measured resistance of NTC.

B is the Beta value - need to be calculated.

ln is the natural logarithm.

r¤ is the reference resistance at a certain K temperature.

[Realtek Ameba RTL8195 - Smart Curtain System]

On 4/14/2020 at 4:00 PM, Michael Zhang said:

The focus of this project is to demonstrates how easy it is for Ameba Wi-Fi Dev. board to communicate with our smart phone via MQTT protocol. Phone to microcontroller communication used to be very difficult as they use totally different hardware interface and phone get its data mainly through the network. Now with a Wi-Fi enabled microcontroller like Ameba RTL8195AM, communication with our phone becomes a bliss. 

Of course, in this video, only a mini window is used for demonstration purpose, but controlling a real  window should not be a problem if you simply replace the servo motor with a bigger DC step motor and change the source code accordingly. 

With this smart curtain system, you may,
1. Remotely control your curtain to open or close instantaneously
2. Check your curtain status according to the MQTT message received 
3. Link with the previous weather station project and automate your room from there

 

 

GitHub page
https://github.com/Realtek-AmebaApp/Ameba_Examples/tree/master/RTL8195AM/005_SMART_CURTAIN

Official pages
https://www.amebaiot.com.cn/en/
https://www.amebaiot.com/en/

Facebook pages
https://www.facebook.com/groups/AmebaIoT/

BiliBili channel
https://space.bilibili.com/45777743

 

Cool

[Voltage drop: Circuit to control fans and leds]

On 7/24/2020 at 11:10 PM, Danirov said:

Hi everyone. Can you help me with this circuit I am working on, please?. (Image 1)

It consists of a TP4056 charger/controller connected to a 3.7v/1.4Ah Li-Ion battery to supply a low battery indicator and a load (3 leds + 2 fans) through a MT3608 Step Up to raise voltage from 3.7v to 9v. When the TP4056 is charging the battery through the USB port, the load is disconnected by the P-Mosfet.

PROBLEM: Voltage drops significantly when the load is connected.

Test1: Circuit without Debouncing/Load connected:
Voltage drops from 3.68v to 3.46v (image 2).
Low Battery Indicator: Blinks.

Test2: Circuit with Debouncing/Load connected:
1) Debouncing Circuit: The voltage drops to 2.19v at the output of the Smichtt Trigger, therefore it isn't possible to energize the Step Up and the rest of the circuit.
2) Low Battery Indicator: Blinks when switch is pressed.

Test3: Circuit with Debouncing/Load disconnected:
1) Debouncing Circuit: Works fine (image 3).
2) Low Battery Indicator: Doesn't blink when the switch is turned ON/OFF.

Is there something that I am forgetting to put in the circuit so the voltage is dropping?
I would suppose that the problem is at the DC/DC conversion of the Step Up, but everything is meeting its requirements (Vin:2v-24v/Imax: 2A).

My system details:
Power consumption: 1.702W
Low Bat Indicator: (0.037W, 3.7v/0.01A)
Load: 2 Fans (1.44W, 9v/0.16A), 3 Leds (0.059W, 2.92v/0.02A).
Debouncing Circuit based on a Schmitt Trigger 74HC14 (Vin:2-6v/Vout:2-VCC, VCC and GND connected to battery line).

Wow, for the fans you need to draw more power externally or as mentioned above , build in a power enhancer (easiest way to implement a power transistor).