In this project, we will be integrating the onboard thermistor with the AnyCloud TCP Client project in the Modus Toolbox. We will be using thermistor libraries and their respective APIs to work with the onboard thermistor.
PSoC 6 Wi-Fi BT Prototyping Kit (CY8CPROTO-062-4343W)
The thermistor is connected to PSoC 6 pin 10.1 and 10.2, as shown on the board.
After successfully adding the library, we need to include the library in the project i.e. #include “mtb_thermistor_ntc_gpio.h”.
The project contains three major source files -
In tcp_client.h we are adding few marcros, which are:
#define THERM_GND P10_0
#define THERM_VDD P10_3
#define THERM_OUT P10_2
NOTE: For CY8CPROTO-62-4343W Kit, we need to swap the GND and VCC pin macros as there is a slight error in the hardware. Hence, the macros for the PROTO kit would look like:
#define THERM_GND P10_3
#define THERM_VDD P10_0
#define THERM_OUT P10_2
In tcp_client.c we are adding the following code:
The thermistor used in this kit is NCP18XH103F03RB. It follows negative temperature coefficient (NTC) characteristics i.e. the resistance decreases with an increase in temperature.
The software flow is as follows:
1. After adding the include files, we need to create few structures for the thermistor as:
/* Refer thermistor datasheet for the values */
.b_const = (float)(3380), // Refers to beta constant
.r_infinity = (float)(0.1192855), //Refers to resistance at infinity
/**Resistance of the thermistor is 10K at 25 degrees C (from datasheet). Therefore R0 = 10000 Ohm, and T0 = 298.15 Kelvin, which gives R_INFINITY = R0 e^(-B_CONSTANT / T0) = 0.1192855 **/
.r_ref = (float)(10000) // Refers to reference resistance
All the above structures will be used in the thermistor APIs for temperature calculations. Ideally, we initialize them as global.
2. Next, we will initialize the thermistor using the pre-defined APIs as:
result = cyhal_adc_init (&adc_obj, THERM_OUT, NULL);
result = mtb_thermistor_ntc_gpio_init (&mtb_thermistor_obj, &adc_obj, THERM_GND,
THERM_VDD, THERM_OUT, &therm_gpio_cfg);
We need to first initialize ADC, and for that, we are using the HAL API of the ADC i.e. cyhal_adc_init () as shown. It takes three arguments, reference to ADC structure, ADC pin (THERM_OUT), and clock. Three GPIO pins of the PSoC are being used here, which are:
As shown on the board, this is an analog pin 10.1 or 10.2, where the thermistor is connected
This is a GPIO pin which will be pulled high acting as VDD for thermistor.
This is a GPIO pin which will be pulled low acting as ground for thermistor.
All these GPIO initialization are done in terms of MACROS in tcp_client.h file.
After ADC initialization, we initialize thermistor GPIO i.e. mtb_thermistor_ntc_gpio_init (). It takes six arguments, reference to thermistor structure, reference to ADC structure, VDD pin, GND pin, Output/ADC pin, and reference to thermistor configuration structure.
3. We are done with the initialization and we shall use the temperature API, which accepts the readings got from ADC and converts them into temperature (degree centigrade).
value = mtb_thermistor_ntc_gpio_get_temp(&mtb_thermistor_obj);
The above API takes one argument as reference to thermistor object and the API returns the floating-point value which is the actual measured temperature in degree centigrade.
4. After getting the values, we simply pass the values into the tcp_client_recv_handler() function, which will simply print the values on UART (i.e. TCP Client) w.r.t. the command received from the TCP Server.
5. If in TCP server, the command sent is “1” then the TCP Client will print the value of thermistor on UART and will acknowledge the TCP Server by sending the same value to it and simultaneously will turn the LED and ADC On. Similarly, if the command is “0”, TCP Client will not send the readings and will turn the LED and ADC OFF as shown in the below figures.
Figure: TCP Client (UART)
Figure: TCP Server (Python)
Note: Please update the WIFI_SSID, WIFI_PASSWORD, and TCP_SERVER_IP_ADDRESS macros in tcp_client.h.
Hope you all like it.
Here is the thing you can try –
Try porting the code in PSoC 6 WiFi BT Pioneer kit (CY8CKIT-062-WiFi BT) using EPD libraries.
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