how to program a 1602a-i2c for arduino with a picaxe chip

dennis shubert

New Member
I have an Orbital i2c lcd works great with picaxe. But I got a 1602a-i2c for arduino a few $ Ebay. I would like to know how to program with a 082m2 picaxe chip. I tried a lot of code I only get a backlight and screen on. no data sent. Does any one have a snippet or some code that will work. I have pins correct c.1 to scl and c.2 to sda and +- Thanks for your time.
 

Technical

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AllyCat

Senior Member
Hi,

I think you need more than a "Code Snippet" because the Orbital LCD looks to be an "intelligent" LCD (at $40 ?), whilst the "few $ 1602a for Arduino" is probably a very "dumb" LCD, dependent on a complex library for the Arduino. It is possible to drive such displays with a PICaxe, but there are a number of different aspects to understand, so I'm not aware of any single block of code to do it all.

Firstly, the I2C probably uses a dumb "expander" chip, which gives 4 data lines and 4 control lines (including one to the Backlight). Thus the LCD controller needs to be "initialised" and then operated in its 2 cycles of 4-bit wide data mode. That is well-described by Inglewoodpete HERE. But instead of sending the signals to pins, you would build up a sequence of bytes to send via the I2C Bus.

Then you will probably need to write subroutines to convert the data/control strings that you may have used with the Orbital LCD (or any other intelligent serial display) to simple sequences of control/data bytes (perhaps using the LOOKUP command). But maybe somebody has a better recall of a PICaxe "Finished (and documented) Project" than I do. ;)

EDIT: There are other threads on the topic, but finding them is hindered because the Search engine considers the terms I2C and LCD to be "Too short or too common" to search for them. :( However, I did find THIS THREAD with a similar OP question.

Cheers, Alan.
 
Last edited:

Flenser

Senior Member
There are other threads on the topic, but finding them is hindered because the Search engine considers the terms I2C and LCD to be "Too short or too common" to search for them.
Alan, The forum posts are indexed by google so you can search for short terms on the picaxeforum site using a google search term like this:
Code:
site:picaxeforum.co.uk 1602 arduino i2c lcd
The first link returned by this search for me was this thread Picaxe 18M2+ and I2C LCD 16x2 display that has some code by Hippy in post #9 and a link to another thread in post #14
 

dennis shubert

New Member
Hi,

I think you need more than a "Code Snippet" because the Orbital LCD looks to be an "intelligent" LCD (at $40 ?), whilst the "few $ 1602a for Arduino" is probably a very "dumb" LCD, dependent on a complex library for the Arduino. It is possible to drive such displays with a PICaxe, but there are a number of different aspects to understand, so I'm not aware of any single block of code to do it all.

Firstly, the I2C probably uses a dumb "expander" chip, which gives 4 data lines and 4 control lines (including one to the Backlight). Thus the LCD controller needs to be "initialised" and then operated in its 2 cycles of 4-bit wide data mode. That is well-described by Inglewoodpete HERE. But instead of sending the signals to pins, you would build up a sequence of bytes to send via the I2C Bus.

Then you will probably need to write subroutines to convert the data/control strings that you may have used with the Orbital LCD (or any other intelligent serial display) to simple sequences of control/data bytes (perhaps using the LOOKUP command). But maybe somebody has a better recall of a PICaxe "Finished (and documented) Project" than I do. ;)

EDIT: There are other threads on the topic, but finding them is hindered because the Search engine considers the terms I2C and LCD to be "Too short or too common" to search for them. :( However, I did find THIS THREAD with a similar OP question.

Cheers, Alan.
Think I will get an arduino and lib may work then Thanks for your time. DCS
 
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