14400 Baud 8N1

[e.chain]

Looking for some source code to send and receive hex files through RS232, with this settings 14400 Baud Rate, 8 Data, Parity none, 1 Stop bit, Thanks.

 

[ericgibbs]

hi,
This should help with the baud rate calculations.

Which type of MCU and programming language ?

 

[e.chain]

Thanks for your quick reply, assembler is what I understand better. It could be 16F628A or 12F series.

 

[Nigel Goodwin]

Check my tutorials, they give assembler for both software and hardware UART's, actually at 9600 baud, but it's trivial to chnage to 14400 baud.

 

[e.chain]

Thanks Nigel, already found your tutorials, I am working on one of them right now.

 

[e.chain]

Hi Nigel, I am working on your 7.1 Tutorial, do you think this will be accurate for 14400 Baud Rate. Sorry I am a beginner.

Start_Delay MOVLW   0x06
            MOVWF   Delay_Count
Start_Wait  NOP
            DECFSZ  Delay_Count , f
            GOTO    Start_Wait
            RETURN

Bit_Delay   MOVLW   0x0C
            MOVWF   Delay_Count
Bit_Wait    NOP
            DECFSZ  Delay_Count , f
            GOTO    Bit_Wait
            RETURN

 

[blueroomelectronics]

If you use a 16F628A there is a hardware USART that does most of the work for you. Just set it and go. Another member here MikeK8LH wrote a baud rate calculator.
**broken link removed**

 

[e.chain]

If you use a 16F628A there is a hardware USART that does most of the work for you. Just set it and go. Another member here MikeK8LH wrote a baud rate calculator.
**broken link removed**

Thanks, but I will have to try with the original formula that is located in the Microchip Document because this program doesn't calculate 14400 Baud Rate.

 

[blueroomelectronics]

What clock frequency are you using? 4MHz?

 

[e.chain]

What clock frequency are you using? 4MHz?

Yes I plan to use the internal 4Mhz of the 16F628A.

 

[e.chain]

I think the correct calculation for the SPRBG is 16.36 using BRGH=1.

 

[ericgibbs]

I think the correct calculation for the SPRBG is 16.36 using BRGH=1.

Another way to give an approximation would be to look at the Baud table on the datasheet [brgh=1]
for the 7.16MHz xtal, 57600 baud is 4 times 14400 and it specifies a figure of 7.

So for 14400 it would be 28.

So 4MHZ/7.16MHz * 25 = 15.6 , nearest integer value is 16.
I didnt calculate the error.

Ideally you want a 7.16MHz xtal

Does this help?

 

[e.chain]

Another way to give an approximation would be to look at the Baud table on the datasheet [brgh=1]
for the 7.16MHz xtal, 57600 baud is 4 times 14400 and it specifies a figure of 7.

So for 14400 it would be 28.

So 4MHZ/7.16MHz * 25 = 15.6 , nearest integer value is 16.
I didnt calculate the error.

Ideally you want a 7.16MHz xtal

Does this help?

Yes, Thank you.