16F913 setup

[PulsarProFX]

Hi Mr. E and all others!

I am new to the LCD "modules" in the 16F913 chip. I'm trying to get a basic breadboard going here using the minimum setup required to just send 2 digits to 2 displays. From there I can figure out everything else the chip needs to do. It's these damn module parameters that is screwing with my head. Specific pins to displays can be any arrangement for now.

The App Note AN1070 and chip data leaves me confused when it comes to using PBP (v2.60) since data references are all in Assembler. Has anyone worked with this chip to arrive at a simple setup to map the pins, and how to setup the "mapping"? Do you need to create a lookup table to output the digits you want. The more I read the more I'm either missing the boat or reading too much into the minimums required to talk to the displays.

Mega thanks, Frank

[bogdan]

...digits to 2 displays...????

post the schematic please (...or lcd model # ... ext osc ?)

[mark_s]

Here is some code I wrote for a 4 digit display and a PIC16F914. There
is no cut and paste solution using these on chip LCD modules. Each LCD
has different number of segments, commons and duty. The best way
to get going is the worksheet located in the LCD section of the data
sheet. Using the LCD data sheet you assign each segment to an LCD register. I can probably help some if you supply the LCD data sheet.

[mark_s]

Code did not attach the first try

[PulsarProFX]

Here is some code I wrote for a 4 digit display and a PIC16F914. There
is no cut and paste solution using these on chip LCD modules. Each LCD
has different number of segments, commons and duty. The best way
to get going is the worksheet located in the LCD section of the data
sheet. Using the LCD data sheet you assign each segment to an LCD register. I can probably help some if you supply the LCD data sheet.

Using the Data Sheet's pin addressing to function names, here's what I've come up with and verified "ok".

COM-0 LCD FUNCTION ADDRESS LCD SEGMENT IC Pin
SEG0 LCDDATA 0,0 Segment "C" 21
SEG1 LCDDATA 0,1 Segment "D" 22
SEG5 LCDDATA 0,5 Segment "E" 7
SEG6 LCDDATA 0,6 Segment "DP" 14
SEG8 LCDDATA 1,0 Segment "F" 18
SEG9 LCDDATA 1,1 Segment "A" 17
SEG10 LCDDATA 1,2 Segment "B" 16
SEG11 LCDDATA 1,3 Segment "G" 15

COM-1 LCD FUNCTION ADDRESS LCD SEGMENT IC Pin
SEG2 LCDDATA 3,2 Segment "G" 23
SEG3 LCDDATA 3,3 Segment "B" 24
SEG4 LCDDATA 3,4 Segment "DP" 6
SEG7 LCDDATA 3,7 Segment "D" 3
SEG12 LCDDATA 4,4 Segment "E" 2
SEG13 LCDDATA 4,5 Segment "A" 28
SEG14 LCDDATA 4,6 Segment "F" 27
SEG15 LCDDATA 4,7 Segment "C" 5

Thanks, Frank

[mark_s]

Hi Frank,
I would need to see a schematic and have the LCD dat sheet to say for
sure if its correct. It looks like you got the idea.

Try blinking a segment

Loop:
LCDDATA0.6 = 1 'Turn on DP
Pause 1000
LCDDATA0.6 = 0 'Turn off DP
Pause 1000
Goto Loop

[PulsarProFX]

Most PIC's have a "weak pull up" for the MCLR pin. On the 16F913, I don't see this is an option in any register, however, on page 220 "Configuration Bits" [CONFIG1] there is a reference to MCLR. To tie it to VDD they say to enter "0" for this binary string. Wouldn't this mean that because you'd use a "0", if not entering CONFIG1 at all, it would automatically default to "0" and apply a weak-pull up on MCLR?

Otherwise, I would have to have a resistor/cap tied to MCLR which I really don't have the room to do if it's not absolutely necessary.

Frank

[mackrackit]

Not sure I understand what you are after but have you
_MCLRE_OFF
and made the pin an input?