zhou-peter/tuya-iotos-embeded-demo-ble-segment-lcd-driver

Tuya IoTOS Embedded Bluetooth LE Segment LCD Driver

Tuya IoTOS Embedded Bluetooth LE Segment LCD Driver

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Introduction

In this demo, we will show you how to implement a 3-digit 7-segment LCD driver and make a segment LCD IoT-enabled. Based on the Tuya IoT Platform, we use Tuya's Bluetooth LE module, SDK, and the Tuya Smart app to connect the LCD to the cloud so that you can feed contents to the LCD using a mobile app. This demo provides segment LCD interfaces to help you quickly implement pin configuration, display content (numerals, strings, characters, and custom characters), screen on/off, blinking effects (blinking times, full-screen blinking, and portion blinking), and the blinking callback.

Get started

Set up development environment

• Install the integrated development environment (IDE) as per your chip platform.

• Find the download URL of the Tuya Bluetooth LE SDK Demo Project from the following table. Refer to the README.md file under each branch to import the project.

  Chip platform	Model	Download URL
  Nordic	nrf52832	tuya_ble_sdk_Demo_Project_nrf52832.git
  Realtek	RTL8762C	tuya_ble_sdk_Demo_Project_rtl8762c.git
  Telink	TLSR825x	tuya_ble_sdk_Demo_Project_tlsr8253.git
  Silicon Labs	BG21	Coming soon.
  Beken	BK3431Q	tuya_ble_sdk_demo_project_bk3431q.git
  Beken	BK3432	tuya_ble_sdk_Demo_Project_bk3432.git
  Cypress	Psoc63	tuya_ble_sdk_Demo_Project_PSoC63.git

Compile and flash

• Edit code

  1. In tuya_ble_app_demo.h, specify the PID of the product you have created on the Tuya IoT Platform.

     #define APP_PRODUCT_ID     "xxxxxxxx"
     

     Change xxxxxxxx to the PID.

  2. In tuya_ble_app_demo.c, specify the authkey and UUID.

     static const char auth_key_test[] = "yyyyyyyy";
     static const char device_id_test[] = "zzzzzzzz";
     

     Change yyyyyyyy to your authkey and zzzzzzzz to your UUID.

• Compile code

  Compile the edited code, download the code to the hardware, and run it. You may need to download the stack and bootloader depending on your chip models. Check the logs and use the third-party Bluetooth debugging app (such as LightBlue for iOS) to verify the Bluetooth broadcast.

File introduction

├── src         /* Source code files */
|    ├── sdk
|    |    └── tuya_uart_common_handler.c        /* Code for UART communication */
|    ├── driver
|    |    └── tuya_seg_lcd.c                    /* Segment LCD driver */
|    ├── platform
|    |    ├── tuya_gpio.c                       /* GPIO driver */
|    |    └── tuya_timer.c                      /* Timer driver */
|    ├── tuya_ble_app_demo.c                    /* Entry file of application layer */
|    └── tuya_demo_seg_lcd_driver.c             /* Sample code */
|
└── include     /* Header files */
     ├── common
     |    └── tuya_common.h                     /* Common types and macros */
     ├── sdk
     |    ├── custom_app_uart_common_handler.h  /* Code for UART communication */
     |    ├── custom_app_product_test.h         /* Implementation of custom production test items */
     |    └── custom_tuya_ble_config.h          /* Application configuration file */
     ├── driver
     |    └── tuya_seg_lcd.h                    /* Segment LCD driver */
     ├── platform
     |    ├── tuya_gpio.h                       /* GPIO driver */
     |    └── tuya_timer.h                      /* Timer driver */
     ├── tuya_ble_app_demo.h                    /* Entry file of application layer */
     └── tuya_demo_seg_lcd_driver.h             /* Sample code */

Entry to application

Entry file: /tuya_ble_app/tuya_ble_app_demo.c

• void tuya_ble_app_init(void) is executed to initialize Tuya IoTOS Embedded Bluetooth LE SDK. This function is executed only once.
• void app_exe() is used to execute the application code. It is executed in a loop.

Data point (DP)

Function	tuya_ble_dp_data_report
Function prototype	tuya_ble_status_t tuya_ble_dp_data_report(uint8_t *p_data,uint32_t len);
Feature overview	Reports DP data.
Parameters	p_data [in]: DP data. len[in]: data length. It cannot exceed TUYA_BLE_REPORT_MAX_DP_DATA_LEN.
Return value	TUYA_BLE_SUCCESS: sent successfully. TUYA_BLE_ERR_INVALID_PARAM: invalid parameter. TUYA_BLE_ERR_INVALID_STATE: failed to send data due to the current Bluetooth connection, such as Bluetooth disconnected. TUYA_BLE_ERR_NO_MEM: failed to request memory allocation. TUYA_BLE_ERR_INVALID_LENGTH: data length error. TUYA_BLE_ERR_NO_EVENT: other errors.
Notes	application calls this function to send DP data to the mobile app.

Parameter description:

The Tuya IoT Platform manages data through DPs. The data generated by any device is abstracted into a DP. DP data consists of four parts, as described below.

• Dp_id: the DP ID of a data point defined on the Tuya IoT platform. It is one byte.

• Dp_type: the data type. It is one byte.

  #define DT_RAW 0 raw type.

  #define DT_BOOL 1 Boolean type.

  #define DT_VALUE 2 value type. The value range is specified when a DP of value type is created on the Tuya IoT Platform.

  #define DT_STRING 3 string type.

  #define DT_ENUM 4 enum type.

  #define DT_BITMAP 5 bitmap type.

• Dp_len: It can be one byte or two bytes. Currently, Bluetooth only supports one byte, so the data of a single DP can be up to 255 bytes.

• Dp_data: the DP data, with dp_len byte(s).

The data that the parameter p_data points to must be packaged in the following format for reporting.

DP 1 data				—	DP n data
1	2	3	4	—	n	n+1	n+2	n+3
Dp_id	Dp_type	Dp_len	Dp_data	—	Dp_id	Dp_type	Dp_len	Dp_data

When this function is called, the maximum data length is TUYA_BLE_REPORT_MAX_DP_DATA_LEN, which is 255+3 currently.

Pin configuration

Peripherals	I/O	Peripherals	I/O
Segment LCD-COM1	PA1	Segment LCD-SEG1	PA0
Segment LCD-COM2	PC2	Segment LCD-SEG2	PC0
Segment LCD-COM3	PC3	Segment LCD-SEG3	PD3
Segment LCD-COM4	PB4	Segment LCD-SEG4	PC1
		Segment LCD-SEG5	PC4
		Segment LCD-SEG6	PB5

Reference

• BLE SDK Guide
• BLE SDK Demo Overview
• Tuya Project Hub

Technical support

You can get support from Tuya with the following methods:

• Tuya Developer Platform
• Help Center
• Service & Support