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

[CuriousOne]

Hello.
Unfortunately, I was not able to read or write any I2C or SPI eeproms with PBP, so as last chance, I'm now looking into 1wire devices.
I have worked with DS18B20 and it poses no issues, but what about EEPROM? any code examples? can't find any....

[Charlie]

Hello.
Unfortunately, I was not able to read or write any I2C or SPI eeproms with PBP, so as last chance, I'm now looking into 1wire devices.
I have worked with DS18B20 and it poses no issues, but what about EEPROM? any code examples? can't find any....

Why can't you use I2C? I have a couple designs that use 24LC512 family with PBP, and no issues. What part number is the 1-wire device you are looking at?

[CuriousOne]

I tried all sample codes and circuits for eeproms posted here
none seems to work for me.
for 1 wire device, haven't bought any yet, just deciding
For experiments i have DS2501-U chip at hands.

[Ioannis]

The I2C works just fine. Used many times the I2CREAD and I2CWRITE commands.

When there was a problem, was always my mistake in address, wrong use of commands (variable vs constant).

Complete diagram along with your misbehaving code would help.

Ioannis

[CuriousOne]

I have posted all that here already.
And this topic is about 1wire eeprom

[Charlie]

I have posted all that here already.
And this topic is about 1wire eeprom

Perhaps you should provide a link to where you have posted it. Not everybody reads every thread posted everywhere. The 1-wire devices tend to be about the same level of complexity as I2C with a few extra limitations, but are only available in a couple sizes and from a single vendor. If you only need 1K or so to identify a board you should be able to get it going easily. We are trying to steer you towards I2C because they are far more popular and if your project needs change, you won't have a lot of options. Not to mention your next project. I2C is easy and works well in PBP, but hey it's your project. You are less likely to find a code example if you need one for 1-wire, that's all.

[richard]

Perhaps you should provide a link to where you have posted it.

here is one
http://www.picbasic.co.uk/forum/showthread.php?t=587
felt like i was like pulling teeth

[CuriousOne]

DS28EC20 has 20KB of EEPROM, and already available from Chinese vendors, for around $1 per IC
I actually need 2KB for font and 256 bytes for each language text (have 8 languages so far) so even 4KB would be ok

[HenrikOlsson]

I would:
1) Use a PIC with enough FLASH to store what needs to be stored (if possible).
2) Use a FLASH-chip with SPI-interface (easier and faster than I2C IMHO)
3) Use a FLASH/EEPROM with I2C interface
4) Wind my own core-memory.
5) Write down the information on paper, have a RaspberryPi with a camera and OCR software and then interface that to the PIC via CAN-bus.
6) Use a fake/clone 1-wire device from China costing less than 1/3 of the original, able to store just half of what I need*, only to find it doesn't work at all.

But hey, that's me :-)

* The DS28EC20 is 20kbit, not kbyte so your 4kbyte of data won't fit - in case you got that mixed up.

/Henrik.

[CuriousOne]

1) Are there any PIC chips with 4KB of EEPROM available?
2) I tried, can't make it work.
3) Also does not work.
4) Running on PIC16F887, code is already tight
5) No open source hardware/software in my projects ever
6) Actually they do work fine.

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.

[richard]

2) I tried, can't make it work.
3) Also does not work.

maybe one day you could post a complete compliable example of what you have tried along with a sketch, schematic or photograph
of how everything is connected instead of useless and inaccurate snippets and zippo data on how anything is really wired
did you even try anything from this thread or am i completely wasting effort on you

[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.