DLP Lightcrafter 4710 I2C write multiple bytes

Pierre Herbelin

Other Parts Discussed in Thread: DLPC3439

Hi,

I'm working on the DLP Lightcrafter 4710 and I want to control the display resolution via I2C commands.
To do that, I send I2C commands via a terminal

i2cset -Y 1 0x1B subaddress value

So I can control a lot of parameters but when I tried to set the screen resolution, but to do so I have to send multiple bytes and I don't know how to do this via the terminal.
Anyone have some clues on how to do this?

Many thanks in advance!

Pierre

over 9 years ago

0 Nadine Estermann over 9 years ago

TI__Genius 10495 points

Hello Pierre,

What terminal are you using ? I might be able to give it a try.

Best regards,

Nadine

0 Pierre Herbelin over 9 years ago in reply to Nadine Estermann

Prodigy 175 points

I'm using a terminal on an android board (odroid C1+ more precisely).
It's an classical linux terminal with I2C commands.

I have successfully set RGB via the terminal so my I2C connection works fine.

Regards,

Pierre

0 Nadine Estermann over 9 years ago in reply to Pierre Herbelin

TI__Genius 10495 points

Hello Pierre,
Unfortunately I am not familiar with this device. Have you tried to get in contact directly with the company who produces the odroid C1+ boards ?
Best regards,
Nadine

0 Pierre Herbelin over 9 years ago in reply to Nadine Estermann

Prodigy 175 points

Hi,

The command isn't linked with the plateform I'm working on, I send this command from a terminal and this is the same command for the raspberry Pi for example or any plateform with an I2C bus based on linux.

In fact, I don't understand what value I have to write in the register 0x12 (for changing display size).

I used the DLPLightcrafter Advanced tool to see the value but it sends 4 bytes in a 8 bits register so I'm confused.

Regards,

0 Nadine Estermann over 9 years ago in reply to Pierre Herbelin

TI__Genius 10495 points

Hello Pierre,

The display size command is 4 bytes long for the DLPC3439.

For example to set the display size to 1920x1080 the command is following:

addr:36, subAddr:12 80 07 38 04

Please also refer to our software programmers guide under following link:

Best regards,

Nadine

0 Pierre Herbelin over 9 years ago in reply to Nadine Estermann

Prodigy 175 points

I know I'm using this datasheet ^^
The thing is, I don't understand how to write 4 bytes in an one byte register (0x12).

Btw, I think the I2c adress is 0x1B instead of 0x36, due to the read/write bit.

Best regards,

Pierre

0 Nadine Estermann over 9 years ago in reply to Pierre Herbelin

TI__Genius 10495 points

Hello Pierre,

I am not sure if I understand your question correctly. You only have to send 5 bytes sequentially to change the display size. The first byte is the sub-address which basically tells our controller in which location he should save the remaining 4 bytes. This virtual register is large enough to hold 4 bytes.

Please take a look at the screenshot below.

The software programmer's guide provides you with the 8 bit I2C address which include the read/write bit. The 7 bit I2C address it 0x1B.

Best regards,

Nadine

0 Pierre Herbelin over 9 years ago in reply to Nadine Estermann

Prodigy 175 points

Ok I understand now :)

That's why I can't modify the screen size using i2cset command (which can send only 2 bytes per commands).
So I think it's not possible to use i2cset to change the display size.

I'll look for another way to send I2C commands!

Thanks for your help!

Pierre

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DLP Lightcrafter 4710 I2C write multiple bytes