Serial help

[andywpg]

I have acquired one of THESE (https://www.sparkfun.com/products/11441) for a project. I was out of I/O lines, and need a 4-digit display. This seemed like a great idea, since I only need the SEROUT2 command and one pin (I'm using the hardware TX and RX for comms to another device).

The datasheet shows the following commands:

Example: Display 12Ab
To display 12Ab, any of the following 4-byte patterns would be acceptable:
[0x01][0x02][0x0A][0x0B] (Actual binary values 1, 2, 10 and 11)
[0x31][0x32][0x41][0x42] (ASCII-code for '1', '2', 'a', 'b')

Or any combination of binary and ASCII values could be used.

Sample Arduino Snippet (Serial mode):

// ... after initializing Serial at the correct baud rate...
Serial.write(0x01); // Hex value for 1, will display '1'
Serial.write('2'); // ASCII value for '2', will display '2'
Serial.write(0x0A); // Hex value for 10, will display 'A'
Serial.write('B'); // ASCII value for 'B', will display 'b'


It also mentions that CLEAR SCREEN is $76 (HEX 76).

I have never used serial on a PIC before, so I know I'm doing something wrong. When I use the following command:


SEROUT2 PORTB.3,84,[HEX 76]

Nothing happens. When I make a variable equal to HEX 76 and send that, still nothing, When I make two variables equal to 118 decimal ($76) and another variable equal to 7, I get '1187' in the display. I have tried IHEX as well, and still no joy. Anyone got any ideas what I'm doing wrong?

Thanks for any help

Andy

[HenrikOlsson]

Hi,
Never used one of those and I don't quite understand what "nothing happens" actually means. Are you saying that you have data on the screen but when executing the Clear Screen command the screen does not clear?

Anyway, the PBP equivalent of the following Arduino code


Serial.write(0x76); // Clear display command, resets cursor
Serial.write(0x01); // Hex value for 1, will display '1'
Serial.write('2'); // ASCII value for '2', will display '2'
Serial.write(0x0A); // Hex value for 10, will display 'A'
Serial.write('B'); // ASCII value for 'B', will display 'b'


would be something like:


SEROUT2 PortB.3, 84, [$76] 'Clear the display
SEROUT2 PortB.3, 84, [$01, "2", $0A, "B"] ' Display 12AB


What if you try:


For i = 0 to 1000
SEROUT2 PortB.3, 84, [$76, DEC4 i]
PAUSE 1000
NEXT


/Henrik.

[andywpg]

Thanks Henrik. I looked over what I wrote, and I was tired at the time. Yes, what I meant was that clear screen did not work, but if I sent decimal numbers, they showed up in the display. I am at work and will try your suggestions tonight.

Thanks
Andy

[andywpg]

Thank you so much Henrik. Your knowledge has once again saved me and I understand it now.

Works great!