LPC MicrocontrollersのトピックRe: LPC1768 UART recieve problem

LPC1768 UART recieve problem

Alex_2221 — Tue, 21 Sep 2021 18:09:20 GMT

Hello everyone, I'm trying to read two temperatures using LM35 and send them to a phone or computer using HC05 in order to control them. I want to send setpoints to the MCU. I tried to send different numbers ( 2 digit numbers) to the MCU and echo them, however I managed to recieve only the first digit of the numbers I was trying to send. I thought maybe I have problems in sending back the numbers and I tried to use the recieved temperature in my code as a setpoint, but it didn't work.

Here is my code. I also added the C file.

Thanks in advance, Alex

Code:

#include <stdio.h>

#include "lpc17xx_gpio.h"
#include "lpc17xx_pinsel.h"
#include "lpc17XX_uart.h"
#include "lpc17XX_adc.h"

#include "Hardware.h"
#include "Delay_RIT.h"

int main()
{
uint8_t buffstr [20];
uint8_t Temprec [1];
uint8_t temprec;

GPIO_SetDir(2,(1<<2),1);

HW_Init();

while(1)
{
uint16_t temp1 = HW_ADC_Read1();
uint16_t temp2 = HW_ADC_Read2();

uint8_t len= sprintf( (char*)buffstr," %u\n %u\n ",temp1,temp2);
UART_Send(LPC_UART3,buffstr,len,NONE_BLOCKING);

UART_Receive(LPC_UART3,Temprec,1,NONE_BLOCKING);

temprec= Temprec[0];

Delay_RIT_ms(1000);

if(temp1>=(temprec+1))
GPIO_ClearValue(2,(1<<2)) ;

else if ( temp1<=temprec)

GPIO_SetValue(2,(1<<2));
}

}

Re: LPC1768 UART recieve problem

Alex_2221 — Tue, 21 Sep 2021 19:33:34 GMT

I use this code for checking if the MCU can echo the number, but whenever I use UART_RECIEV ( blocking) I can correctly echo back the number, but it only works once and I can't recieve anything else from the MCU like the temperatures of the two sensors and if I use UART_RECIEV ( none-blocking) I can only echo back the first digit of the number, but can recieve the temperature and change the number that I am sending as a setpoint:

UART_Receive(LPC_UART3,Temprec,2,NONE_BLOCKING);

UART_Send(LPC_UART3,Temprec,2,BLOCKING);

Re: LPC1768 UART recieve problem

Alex_2221 — Tue, 21 Sep 2021 19:35:52 GMT

@xiangjun_rong What do you think about this?

Re: LPC1768 UART recieve problem

xiangjun_rong — Wed, 22 Sep 2021 03:16:44 GMT

Hi,

How about using the code:

uint8_t counter;

while(1)
{
uint16_t temp1 = HW_ADC_Read1();
uint16_t temp2 = HW_ADC_Read2();

uint8_t len= sprintf( (char*)buffstr," %u\n %u\n ",temp1,temp2);

counter=len-1;

while(1)

{
UART_Send(LPC_UART3,buffstr[counter],1,BLOCKING);

UART_Receive(LPC_UART3,Temprec,1,BLOCKING);

if(counter==0) break;

counter--;

}

temprec= Temprec[0];

Delay_RIT_ms(1000);

if(temp1>=(temprec+1))
GPIO_ClearValue(2,(1<<2)) ;

else if ( temp1<=temprec)

GPIO_SetValue(2,(1<<2));
}

pls have a try

XiangJun Rong

Re: LPC1768 UART recieve problem

Alex_2221 — Wed, 22 Sep 2021 16:34:45 GMT

Thank you very much. I'll try it and will let you know if it works for me.

Re: LPC1768 UART recieve problem

Alex_2221 — Thu, 23 Sep 2021 18:54:14 GMT

I tested your code. I was able to receive the number that I send via HC05 successfully, but I don't recieve the temperatures of the sensors on my phone continously anymore.