POS Terminal Library

POS Device Communication Library via RS232 for STM32, other microcontrollers, and C programs

Release

Version: 1.0.0

• Type: Software/Embedded Software.

• Support :

           - STM32 series  
           - Arduino
           - C/C++ Programs  
  

• Program Language: C

• Requirement Libraries: [HAL Driver for STM32]

• Properties:

           - Support STM32, Arduino and other C/C++ Programs  
           - Easily communicate with the POS device
           - Get complete transaction information
           - Adapt your program to various payment statuses
           - Callback and Non-blocking Mode Support
  

• Changelog:

           -   
  

Overview

Types:

• enum POS_TransactionResultTypeDef: Result of Transaction, Params:

    - TRANSACTION_SUCCESS
    - TRANSACTION_CANCEL
    - TRANSACTION_WRONG_PASSWORD
    - TRANSACTION_POS_TIMEOUT
    - TRANSACTION_NETWORK_ERROR
    - TRANSACTION_INSUFFICIENT_FUNDS
    - TRANSACTION_TIMEOUT
    - TRANSACTION_WRONG_RESULT
    - TRANSACTION_PACKET_ERROR

• enum POS_StatusTypeDef: Status of POS Operation, Params:

    - POS_ERROR
    - POS_OK

• struct POS_TransactionInfoTypeDef: Transaction Parameters, Params:

    /* ...... Transaction Date ..... */
    uint16_t Year;
    uint8_t  Month;
    uint8_t  Day;
    
    /* ...... Transaction Time ..... */
    uint8_t  Hour;
    uint8_t  Minute;
    uint8_t  Second;
    
    /* ............................. */
    uint32_t Fee;
    
    char CardNumber[];
    char ReferenceNumber[];
    char TrackingNumber[];
    char MerchantID[];
    char TerminalID[];

• struct POS_TypeDef: POS Handle Type

Macros:

- None 

Initialization and de-initialization functions:

- None 

Operation functions:

/* ..................... POS - Transaction ..................... */
POS_StatusTypeDef POS_SendTransaction(POS_TypeDef *POS, char *TotalFee, uint32_t Timeout);

/* ..................... POS - ISR Handler ..................... */
void POS_UART_ISRHandler(POS_TypeDef *POS, uint8_t uData);
void POS_TimingHandler(POS_TypeDef *POS);

/* ...................... POS - Callback ....................... */
void POS_TransactionCallback(POS_TransactionResultTypeDef TransactionResult, POS_TransactionInfoTypeDef TransactionInfo);

Guide

This library can be used as follows:

1. Add pos_terminal.h and pos_terminal_conf.h header

2. Add required headers in pos_terminal_conf.h header, for example:

#include "main.h"
#include "usart.h"

3. Define the POS_TypeDef object in global section of your C Code, for example:

POS_TypeDef MainPOS;

4. Add the POS_UART_ISRHandler function in UART Rx ISR, for example:

void UART_RxISR(uint8_t ReceivedValue)
{
    POS_UART_ISRHandler(&MainPOS, ReceivedValue);
}

5. Add the TransactionCallback function in your C Code, for example:

void POS_TransactionCallback(POS_TransactionResultTypeDef TransactionResult, POS_TransactionInfoTypeDef TransactionInfo)
{
  // Some code to get transaction status and parameters
}

6. Add the POS_TimingHandler function in Loop or TimerISR, for example:

int main()
{
  while (1)
  {
    POS_TimingHandler(&MainPOS);
  }
}

7. Start transaction with POS_SendTransaction function, for example:

int main()
{
  while (1)
  {
    POS_SendTransaction(&MainPOS, Fee, 30000);
    POS_TimingHandler(&MainPOS);
  }
}

Examples

Example 1: Transaction via STM32

#include "main.h"
#include "usart.h"
#include "gpio.h"

#include <stdio.h>
#include "pos_terminal.h"

/* ----------------- Global Variable ------------------- */
uint8_t uartData = 0;
char Fee[] = "50000";
char msg[300] = { 0 };

POS_TypeDef MainPOS;

/* ----------------- USART Interrupt ------------------- */
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
	HAL_UART_Receive_IT(&huart2, &uartData, 1);
	POS_UART_ISRHandler(&MainPOS, uartData);
}

/* ------------------- POS Callback -------------------- */
void POS_TransactionCallback(POS_TransactionResultTypeDef TransactionResult, POS_TransactionInfoTypeDef TransactionInfo)
{
	
	switch (TransactionResult)
	{
		case TRANSACTION_SUCCESS:
		{
			sprintf(msg, "Transaction Success:\nFee:%lu\nDate:%d:%d:%d\nTime:%d:%d:%d\nCard Number:%s\nReference Number:%s\nTracking Number:%s\nTerminal:%s\n", TransactionInfo.Fee, TransactionInfo.Year, TransactionInfo.Month, TransactionInfo.Day, TransactionInfo.Hour, TransactionInfo.Minute, TransactionInfo.Second, TransactionInfo.CardNumber, TransactionInfo.ReferenceNumber, TransactionInfo.TrackingNumber, TransactionInfo.TerminalID);
			HAL_UART_Transmit(&huart1, (uint8_t*)msg, strlen(msg), 100);
		}
		break;

		case TRANSACTION_CANCEL:
		{
			HAL_UART_Transmit(&huart1, (uint8_t*)"Transaction Cancel\n", strlen("Transaction Cancel\n"), 100);
		}
		break;

		case TRANSACTION_WRONG_PASSWORD:
		{
			HAL_UART_Transmit(&huart1, (uint8_t*)"Wrong Password\n", strlen("Wrong Password\n"), 100);
		}
		break;

		case TRANSACTION_NETWORK_ERROR:
		{
			HAL_UART_Transmit(&huart1, (uint8_t*)"Network Error\n", strlen("Network Error\n"), 100);
		}
		break;
		
		case TRANSACTION_INSUFFICIENT_FUNDS:
		{
			HAL_UART_Transmit(&huart1, (uint8_t*)"Insufficient Funds\n", strlen("Insufficient Funds\n"), 100);
		}
		break;

		case TRANSACTION_POS_TIMEOUT:
		{
			HAL_UART_Transmit(&huart1, (uint8_t*)"POS Timeout\n", strlen("POS Timeout\n"), 100);
		}
		break;

		case TRANSACTION_TIMEOUT:
		{
			HAL_UART_Transmit(&huart1, (uint8_t*)"Transaction Timeout\n", strlen("Transaction Timeout\n"), 100);
		}
		break;

		case TRANSACTION_WRONG_RESULT:
		{
			HAL_UART_Transmit(&huart1, (uint8_t*)"Transaction Wrong Error\n", strlen("Transaction Wrong Error\n"), 100);
		}
		break;

		case TRANSACTION_PACKET_ERROR:
		{
			HAL_UART_Transmit(&huart1, (uint8_t*)"Packet Error\n", strlen("Packet Error\n"), 100);
		}
		break;
		
		default:
		break;
	}
	
}

/* ----------------------------------------------------- */
int main(void)
{
	/* Initialize SPI, GPIO, and requirement hardware */
	SystemClock_Config();
	MX_GPIO_Init();
	MX_USART1_UART_Init();
	MX_USART2_UART_Init();
  
	/* ---------------------------------------------- */
	MainPOS.UARTx = &huart2;

	HAL_UART_Receive_IT(&huart2, &data, 1);

	HAL_UART_Transmit(&huart1, (uint8_t *)"Hello, <Push Key to send transaction>\n", strlen("Hello, <Push Key to send transaction>\n"), 100);
	
	while (1)
	{
		if (HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_0) == 0)
		{
			POS_SendTransaction(&MainPOS, Fee, 30000);
		}

		POS_TimingHandler(&MainPOS);
	}
}

Test Performed:

• STM32F1
• Arduino
• AVR

Developer: Majid Derhambakhsh