Help with USART

gabriel.moreano.epn · Joined: 03 Sep 2013 Posts: 12

Hello everyone my name is Gabriel, I have a problem with USART communication, I need to connect two atmega and that they have the same temperature value read from a sensor, I can send a character (print chr) and read in the atmega 2 with a inkey () but I need to know if you could send and read numbers with decimals, eg 37.5, the programs I'm using both atmegas is:

ATMEGA2

'1 Configuracion Principal

$regfile = "m164pdef.dat"
$crystal = 8000000
$baud = 9600

'2 Configuracion de Puertos

Ddra = &B00000000
Porta = &B00000000

'3 Configuracion de Perifericos

Config Com1 = 9600 , Synchrone = 0 , Parity = None , Stopbits = 1 , Databits = 8 , Clockpol = 0

Config Lcd = 16 * 2
Config Lcdbus = 4
Config Lcdpin = Pin , Db4 = Portb.0 , Db5 = Portb.1 , Db6 = Portb.2 , Db7 = Portb.3 , E = Portb.4 , Rs = Portb.5
Cls
Cursor Off

Config Adc = Single , Prescaler = Auto
Start Adc

'4 Definicion de Variables

Dim Temp As Word , Temp1 As Word
Dim Temperatura As Single , Temperatura1 As Byte
Dim Tempcabina As Single , Tempcabina1 As Byte
Dim A As Single
A = 100 / 1024

'5 Programa Principal

Do

Temp = Getadc(0)
Waitms 150
Temp1 = Getadc(1)
Waitms 150

Temperatura = Temp * A
Tempcabina = Temp1 * A

Temperatura1 = Temperatura
Tempcabina1 = Tempcabina

Print Chr(temperatura1)
Print Chr(tempcabina1)

Locate 1 , 1
Lcd "temp: " ; Fusing(temperatura , "##.#")
Locate 2 , 1
Lcd "tcabina: " ; Tempcabina1

Loop

ATMEGA 2

'1 Configuracion Principal

$regfile = "m164pdef.dat"
$crystal = 8000000

'2 Configuracion de Puertos

Ddra = &B00000000
Porta = &B00000000

'3 Configuracion de Perifericos

Config Com1 = 9600 , Synchrone = 0 , Parity = None , Stopbits = 1 , Databits = 8 , Clockpol = 0

Config Serialin = Buffered , Size = 4

Enable Interrupts

Config Lcd = 16 * 2
Config Lcdbus = 4
Config Lcdpin = Pin , Db4 = Portb.0 , Db5 = Portb.1 , Db6 = Portb.2 , Db7 = Portb.3 , E = Portb.4 , Rs = Portb.5
Cls
Cursor Off

'4 Definicion de Variables

Dim Temperatura(3) As Byte , Auxtemp As Byte
Dim Tempcabina As Byte , Auxtempcabina As Byte
Dim Aux As Byte , Aux1 As Byte
Dim Oxigeno As Byte
Dim Cardiaco As Byte
Dim Humedad As Byte
Dim Settemp As Byte
Dim Sethumedad As Byte

Oxigeno = 93
Cardiaco = 65
Humedad = 55
Settemp = 37
Sethumedad = 55

'5 Programa Principal

Do

Aux = Ischarwaiting()
If Aux = 1 Then
Temperatura(1) = Inkey()
Temperatura(2) = Inkey()
Temperatura(3) = Inkey()
If Temperatura(1) > 0 Then
Auxtemp = Temperatura(1)
Else
End If
Else
End If

Aux1 = Ischarwaiting()
If Aux1 = 1 Then
Tempcabina = Inkey()
If Tempcabina > 0 Then
Auxtempcabina = Tempcabina
Else
End If
Else
End If

Locate 1 , 1
Lcd "temp: " ; Auxtemp ; " "
Locate 2 , 1
Lcd "tcabina: " ; Auxtempcabina ; " "

Print Auxtemp
Print Auxtempcabina
Print Oxigeno
Print Cardiaco
Print Humedad
Print Settemp
Print Sethumedad

Loop

(BASCOM-AVR version : 2.0.7.7 )

EDC · Joined: 26 Mar 2014 Posts: 702

First -> Made shortcut to Wiki Very Happy

http://wiki.mcselec.com/bavr/BASCOM-AVR_Help

Easier to read than help pdf. Read : PRINT, FUSING, ISCHARWAITING, INPUT, INKEY, WAITKEY and ECHO. All with examples there.

Then You can think... You can print String like

gabriel.moreano.epn · Joined: 03 Sep 2013 Posts: 12

Might you give me a code example of how to read the number with decimals in atmega, the shipping is no problem but reading

JC · Joined: 15 Dec 2007 Posts: 490 Location: Cleveland, OH

I don't know if you are running a simulation, or on real hardware.

Your schematics for the power and ground connections are NOT the same on the two micros.

Note that Vcc AND AVcc must be tied to V+. You have not shown the connection on the second micro.

Note that BOTH grounds on the M164 need to be tied to ground.

You show ARef tied to Vcc on one micro. Do NOT do this. This can damage the micro.
You can connect ARef to a cap to ground.

JC

EDC · Joined: 26 Mar 2014 Posts: 702

Here You have a tested one.