Help with LCD117

#1
Hi
I am assembling a small project from parts I have in my storage bin. This project is using an LCD display. I have difficulties displaying anything but the cursor and some "X's". I am using an NOS 14M chip along with a LCD117 driver chip, ordered long time ago from PH.Anderson (RIP) Here is my short test code for the display:
Code:
High 0 ' Be sure Tx Pin is idle for some time
Pause 5000 ' wait for PICAXE LCD to boot
SerOut 0, T2400, ("?G216") ' configure LCD as 2 X 16
main:
SerOut 0, T2400, ("?f") ' clear the LCD and home the cursor
Pause 100
SerOut 0, T2400, ("PICAXE LCD117") ' send text only, first line is automatic
SerOut 0, T2400, ("?i?iPicaxe&LCD?n")
Pause 2000 ' pause to admire
SerOut 0, T2400, ("?f")
SerOut 0, T2400, ("?0?1?2?3?4?5?6?7?n") ' display special characters
SerOut 0, T2400, ("That's It")
Pause 5000 ' pause to admire
Goto main
I am using pretty common 2 x 16 LCD display QC1602. Datasheet here: https://www.mpja.com/download/QC1602a.pdf
The LCD117 driver chip label says: LCD #117 9600 baud, my code is using 2400 baud. Is that the problem?
 

RNovember

Well-known member
#2
The LCD117 driver chip label says: LCD #117 9600 baud, my code is using 2400 baud. Is that the problem?
The driver chip probably won't read the information right if it expects 9600 baud, and is getting 2400.

I have never tried those drivers, or any LCD project ever, but that seems logical to me.

Does your code need to run at 2400 baud? If not, why not bump it up, and see if it works.
 
#3
I have one of the Anderson serial-to-parallel LCD driver chips. Mine definitely works at 2400 baud. However, if yours is marked 9600, then try feeding it data at the higher rate. You can't do any damage.
 

Pongo

Senior Member
#4
Later versions of the LCD117 were (are?) available in 2400, 4800, 9600 and 19,200 baud. If it's marked LCD117 9600 then it will only work at 9600 baud.
 
#5
Will the 14M support 9600 baud? I taught 2400 baud is max?
Update: the editor won't let me use 9600 baud, so the 14M doesn't support it.
I have a bunch of these old picaxe chips and wanted to use them up in some simple projects.
Oh well, I'll try to re-programm the driver chip with 2400 baud code
 
Last edited:

hippy

Technical Support
Staff member
#6
Will the 14M support 9600 baud? I taught 2400 baud is max?
Update: the editor won't let me use 9600 baud, so the 14M doesn't support it.
With the 14M2 running at 8MHz it should work. Add a SETFREQ command, double the length of all your PAUSE commands, change all T2400 to T9600_8 ...
Rich (BB code):
#Picaxe 14M
SetFreq M8
High 0
Pause 10000
SerOut 0, T9600_8, ("?G216")
etc
 

julianE

Senior Member
#8
the code for LCD117 is in public domain,

lcd117

has anyone tried programming a raw pic chip with the software?
I have a PICkit 3 but I'm not sure what else is needed.

In the instruction,
phanderson

it mentions "In order to compile and burn the firmware source code to a chip you will need a copy of CCS's PIC-C Compiler. (BBR)"

Is that compiler available free?

Thanks in advance.
 

julianE

Senior Member
#10
I would use Microchip's MPLAB-X (free IDE) but that's because I use it regularly.
I remembered that the zipped file has .hex files so it's all ready for programming. I do have the mplab-x ide loaded. Now, I just have to wait until I have enough items for ordering from Mouser in order to offset the shipping costs. The chip that PHAnderson used is 16F1827.
 
#12
16F1826 is similar, with less memory. You can do a parametric search on the Microchip website. The only criteria would probably be 18-pins, EUSART, 16-bit Timer0 and sufficient memory (flash and RAM) but please do your own research to ensure your substitute is suitable. You could also use a larger chip (20 or 28 pins) but you might have to rearrange the pin functions.
 
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