axe033 message programming i2c

[dorfusf]

Good day to all.

Can you please help me?
I got a Axe033 connected to a 20x2 in i2c mode and I would like to know how I can program the 8 messages on the axe033 via i2c and display them. I can program the time and display the time and other messages from the 20x2. I'm fairly new to i2c so any help would be appreciated.

Thanks

 

[westaust55]

Firstly, welcome to the PICAXE forum.

In i2c mode, the AXE033 acts very much like a “dumb” display/device.
Believe that pre-defined messages can only be set up in serial mode.

 

[dorfusf]

Thanks Westaust55 for your welcome and reply.

One more Q can you display pre-programmed messages via i2c if you have pre-programmed them via serial?

 

[hippy]

I don't know if it's possible to use I2C to show messages pre-programmed by serial, I suspect not. As you have an AXE033, perhaps the expedient thing is to try it and see what happens, which is what I'd guess any other forum reader would have to do to give you a definitive answer.

 

[westaust55]

As mentioned in previous post, the i2c mode is relatively “dumb”.

Untried, but I believe there is no mechanism to create or display a pre defined message in i2c mode.

Section 2 of the datasheet covers i2c comms but there is no mention of pre-defined messages, whereas Section 3 covers serial mode and does detail creation and display of pre-defined messages.

i2c mode enables you to read the time from the DS1307 RTC when fitted but you do lose other features.

 

[BeanieBots]

I concur with westaust.
To the best of my knowledge, when using I2C, it is up to you to send everything required to the LCD. Only serial has the extra 'functions' available.

For what it's worth, my approach has always been to use the display in serial mode and fit the RTC on the PICAXE board using the I2C commands. A sort of 'best of both worlds'.

 

[Erik van Gerven]

Serial and I2C simultaniously

Th I2C bus and serial connections are separate on the AXE033. No problem to send data to the LCD using serial mode and using the RTC on the I2C bus at the same time where the RTC is fitted on the axe033.

 

[westaust55]

Eric have you actually done this - using i2c and serial concurrently on an AXE033?

I tried some tests myself tonight. Admittedly I was only testing the LCD side and not trying to concurrently read the RTC.

If you try in i2c mode with a line like:
writei2c 0, (253,2,255)
in the vain hope that the 253 might bring up the special comamnds and the 2 produce pre-defined message 2 all I get is the divide symbol (char 253).

There is a mode link (J2) to select between i2c and serial mode.

with the AXE033 set up in i2c mode and sending a SEROUT command via the serial line to print text does nothing.

removing the mode link (J2) on the fly does not drop the AXE033 into serial mode. Had to turn power off and back on again for Serial mode to be established.

Thus in conclusion:

1. i2c mode will not permit use of the pre-defined messages. i2c is relatively "dumb" as the datasheet indicates.

2. the mode (i2c or serial) is established at power up and even changing the mode link (J2) will not permit changing to the second mode "on the fly"

 

[dorfusf]

Thank you for all the replies.

Westaust55 I tried the same and got the same results. Bummer. I'll just stick with writing everything in the 20x2 then putting it out on i2c as I do need it to read the RTC. The good thing is that it has got lots of memory.

Thanks again.

 

[Erik van Gerven]

I mentioned only the use of I2C for the clock-option (RTC) concurently with the LCD display in serial mode.
The jumper must be in serial-mode and so the LCD will not respond to I2C commands while the RTC still does, just as any other I2C device connected.

I did quit a bit using I2C devices on picaxe but like the Axe33 connected for easy output.
Since the serial mode is more convenient, I used that several times.

 

[westaust55]

Thanks for the clarification Eric.

Good to know that the method you describe will work as you say.
Certainly not explained in the AXE033 datasheet for concurrent use with RTC via i2c and LCD via serial.