1Wire serial EEPROM, DS28EC20 and similar, any experience?

[HenrikOlsson]

1) Are there any PIC chips with 4KB of EEPROM available?

I don't know, haven't checked but I did not say EEPROM, I said FLASH. You can store things in the program memory, after all that's how the program is held in there right.

2) I tried, can't make it work.

Allright, post your code and we might be able to help.

3) Also does not work.

Allright, post your code and we might be able to help.

4) Running on PIC16F887, code is already tight

Use something slightly more modern then. 18F46K42 has 64k of FLASH and 4k of RAM, 18F47K42 doubles that again and they are both cheaper than the old 16F887.

5) No open source hardware/software in my projects ever

OK, yet you're scouring the forum for code to use - strange.

6) Actually they do work fine.

Well, there you go - in that case use it.

And regarding the DS28EC20, if you noted, topic reads "DS28EC20 and similar" This means, that in case of need, say, DS2505 can be used, which has 64k.

As far as I can see the DS2505 is 16kbit, not 64kbit. It can talk to the uC at 16.3kbit / second - that's insanely slow even compared to I2C (if speed doesn't matter then fine, no problem). And it's an "add-only" memory meaning you can program it over the 1-wire bus but one time only, there's no way to erase it.

/Henrik.

[CuriousOne]

I'm getting 16F887 for about 30 cents Ones you mentioned cost 10-20 times more

For the I2C/SPI EEPROM I already had separate topics open with code posted, but nothing happened

And 1 wire has it's own advantages - it needs 1 wire to work My current project uses TQFP-44 PIC16F887
and there is LCD screen, DS3231, TM1639, keypad, USB PD trigger and whole bunch of various hardware
attached to it, so in search for available pins, I have to do tricky things, like using piezo buzzer for alarm, and combining
that pin with LCD enable pin

Similarily, I have no issues with OTP ROM - all it has to do is contain static text strings and font data - no need to update
it ever

Oh by the way, I've implemented famous Casio VL-1 "Da da da" beeper rhythm playback with PBP, after I polish the code, will post it for public

[mpgmike]

Similarily, I have no issues with OTP ROM - all it has to do is contain static text strings and font data - no need to update
it ever

If you create Constant (CON) strings, you can store them categorically within a CALL/GOSUB routine. Using a Line variable (Line VAR BYTE) just set that to the text line needed.

Line VAR BYTE
Language VAR BYTE
String VAR BYTE[16] 'String buffer to hold ASCII text

Main:
Line = 1 'Welcome
IF Language = 1 THEN 'English
 GOSUB Get_English
ELSEIF Language = 2 THEN 'Spanish
 GOSUB Get_Spanish
ELSEIF Language = 3 THEN 'German
 GOSUB Get_German
ENDIF

Get_English:
 SELECT CASE Line
  CASE = 1 : String = "Welcome"
  CASE = 2 : String = "Select Language"
  CASE = 3 : String = ...etc
 END SELECT
RETURN

Get_Spanish:
 SELECT CASE Line
  CASE = 1 : String = "Bienvenidos"
  CASE = 2 : String = "sel idioma"
  CASE = 3 : String = ...etc
 END SELECT
RETURN

Get_German:
 SELECT CASE Line
  CASE = 1 : String = "Willkommen"
  CASE = 2 : String = "Sprache auswählen"
  CASE = 3 : String = ...etc

This should give you the idea.