Matrix Orbital Corp

I am trying to load startup splash screen for LK404-55. Manual gives format as follows: "254 64 [80 char]" and description says "Loads new startup screen (160 characters)." Note 80 characters is not enough for 160 character display. When I try to use this command, it seems to take the first 80 characters but anything sent after 80 characters shows up on the display as two thin vertical lines (||) in one character position. Right now my startup screen is an asteric at position 1,1 and the rest of screen is filled with these || characters. Also, after sending failed "Load startup screen" command, unit will not respond to further commands until it is power cycled. Any assistance on this would be greatly appreciated.

I responded by email.

Tom, thanks for your help. I just wanted to post solution for the benefit of others...

First, [80 char] is a mistake in LK404-55 User Manual. It should read [160 char].

Second, my problem using the Load Startup Screen command was associated with my use of I2C interface. (For my case, RS232 was not an otpion.) MO said the command was incompatible with I2C but I noticed that the first character for the splash was actually saved correctly and all others were corrupted. I figured that since this command must write to non-volatile memory, it might be a data timing issue. So, I put a delay between each character send and noticed more characters were stored. By the way, MO tells me there's a 96 character input buffer on the unit. Anyway, I ended up increasing the delay to about 33 mS and it works. It may work with less delay but I'm not inclined to fine tune this since I rarely need to use the function anyway.

Hi,

The reason I told you about the compatibilty of the start up screen in I2C is directly related to the timing issues involved. The timing for an alpha numeric is easier to accomplish then our graphic displays. Depending on a customer's application and setup, timing can change from app to app.

Best Regards,

Tom,

I'm not sure I follow. You originally agreed with me that it was a timing issue related to time to write data to EEPROM. That made sense and so I then asked for a value for required time delay between bytes to allow for the EEPROM write cycle. The response was that the load start-up screen was not compatible with I2C and could only be used in RS232 interface. In reality, the only thing required to make this work was adequate time delay to allow for writing each byte to EEPROM. The delay time required is a function of the LCD EEPROM and is not affected by customer's application. I don't see how application can affect how long it takes the LCD to write data to it's EEPROM.

Anyway, Thanks for your help.

Best regards,
Chester

The biggest issue here is how we use the I2C protocol. We have alphanumeric and graphic displays that obviously handle data differently. We are currently in the process at Matrix Orbital to unify our command structure, thus implementing consistancy across our product line. We have noticed slight discrepancies from unit to unit which we are resolving. I2C plays a big part, as some of our modules have memory chips (you can load a start up screen with this) and some don't, therefore limiting our guideline for I2C. If you have any further questions or concerns, feel free to post or you can contact me directly at myero@matrixorbital.ca