TTL LCD text sending

A

Akat

New Member
i'm sorry if this turn out to be a silly question..
i just bought serial LCD character 20x4 for my project which have 2 type of input can be feed in, one is via RS232 serial and another one is TTL.. i just dont understand which one is the best for me to send a text via serial using serout, exp. serout 0,T4800,("bla bla bla...")

and.. what is TTL interface actually??? when can we use it? the diagram of TTL solution looks like very simple to interface with, i'm interested to try but don't know how to, especially to send a text to the LCD.

btw, the LCD can only be set to 9600 (by default) and 19200 baudrate.. if i'm using 18x, and i overclock the chip to 8MHz instead, am i using the right command for previewing the text? exp. serout 0,T4800,("bla bla bla")... seems like it doesnt wanna show me the right character come out..
 
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I

inglewoodpete

Senior Member
TTL used 0v for a '0' and +5v for '1'. Officially, RS232 uses +12v for '1' and -12v for '0' but there are many variations on this like +5v/-5v and even +5v/0v.

Check 'SerOut' in the latest command manual for serial speeds when clocking up a PICAXE to M8 or M16.
 
K

kevrus

New Member
serout 0,T4800,("bla bla bla")...
Click to expand...
Don't forget to include the LCD commands and the LCD line/position in your 'serout'...i.e serout 0,t4800,(254,128,"write text here")...this will write to line 1 from position 1
254 is the command to write
also bear in mind the way that the 4x20 lines are configured...
128 is the start of line 1
192 is the start of line 2
148 is the start of line 3
212 is the start of line 4
 
E

eclectic

Moderator
Akat.

Download

http://www.rev-ed.co.uk/docs/axe033.pdf

and read
page 8; connecting to the Picaxe, then
page 9, “Control Commands”

Obviously, you need to adjust

Pinout, N or T, and 2400.

e

Added. Please can you post a link to the Datasheet for your LCD.
It may help others give you more advice.
 
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papaof2

Senior Member
From the datasheet: the connection would be to the TTL input pins and the PICAXE data format would be N4800 (at 8MHz) as the serial format is 8N1
The data sheet lists the cursor control and position commands. This display also does autowrap from line to line and has an optional backlight timer setting that turns the backlight off after X seconds - good option for battery powered devices.

John
 
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