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15 years passed since last post :D
I ordered ST7920, but seller sent these instead by mistake. 240x64 resolution. They're on the way, and I'll give them a try once they arrive.
But what I've...

Yes, found some sample code for hardware I2C listed here. Reading thru them slowly....

By the way, as PIC16F886 datasheet says:

Master Synchronous Serial Port (MSSP) Module
supporting 3-wire SPI (all 4 modes) and I2C™
Master and Slave Modes with I2C Address Mask

This means, I...

So only one way to get the speed, is to use SPI, but with MSSP?

Ok, measured I2C CLK speed. it is about 48khz. So I guess, this is the main issue, right?

Well, I don't see anything to be slow at 8mhz, except I2C :D
Had no time today, will measure I2C frequency tomorrow and post back....

The issue is that these boundaries should be changeable, since different chars will have different pixel width.
There are two ways of doing this - all capitals have same width and all non-capital...

Hello.
I'm upgrading my ST7920 "library", so letters can have variable width, for better visual appearance.
For this purpose, I plan to have single, screen-wide bit array, in which I will write the...

Not yet, but will do. Measure what, I2C clock frequency?
Tried modifying code in a way, that only that part of screen is redrawn, which is being updated. For some uses it does helps, but not always.

Good.
So I have to "learn" to use SPI eeprom 1st, and then use MSSP :)
By the way, if I leave current setup as is - using I2C, but use PIC running at say 32mhz (instead of current 8mhz), will this...

Thanks, but that code is missing SSPBUF declaration?

Well I tried software SPI with MAX7219 and was not impressed at all - updating 32x8 pixels led display was quite slow....

Well, just added these square brackets - see no difference in readings.

Big thanks Richard! now it works!

here's the code:


adr=$46
x=0
cnt=%0100011
i2cwrite ldta, lclk, adr, cnt
pause 200

The main difference between us is the sourcing capabilities :)
I'm buying everything from china, so I'm paying about 3 cents for 24C256 and parallel eeprom is somewhere around 40 cents. I guess, I...

Thanks everyone.
So let's answer step by step.
There are no significant delays with ST7920 itself nor SPI should be used for it. I'm looking for best compatibility, and with LCDOUT it works like...

24C256 is 32KB EEPROM.
So I'm using it, because I need that much amount of font/graphics data :)

I'm using 24C256 for a good reason - due to amount of data being used :)
Also, when using program memory, it won't be that easy to form the letters, as I do in the example above.

Hello.
There are LCD modules, based on ST7920 controller, which are pin and command compatible with HD44780 controllers, so they can be used with PBP, by using LCDOUT statement. This saves a lot of...

Thanks!
Tried both, none works, so I guess, I'm missing something else too...

Changed syntax, still getting zeroes, what I'm doing wrong?



ldta var porta.6
lclk var porta.3

x var word
y var byte
z var byte

So by checking the last bit, I can know, whenever variable went into negative world, right?

Well, I tried to use what I already have working for DS3231 :)
Manual is not very clear about I2C....

8 years passed and now I'm giving it 2nd try, but it still does not works (returns 58317 constantly). Here's code:



ldta var porta.6
lclk var porta.3


x var word
adr var byte

Variable value should go to negative, but since we have no negative, it goes into 65xxx range :)