Hi tony,

You said when transmitting an ODD value onto the bus, the trace looks fine..
Is the data on the 9th clock (ACK bit) high? It should be.

The slave ACKs the 0xC6 address and the 0x00 register byte; the ACK for the 0x05 data is the same (low). If it is hardware, I wonder why the slave has no ...

Hi tony,

The ACK for all the data you send is all low (ACK of course). So just like how the slave ACKs the address 0xC6, the register 0x00, and the even data, it should ACK the same to the odd data, because obviously, it accepts the data and action is performed accordingly.

It must be then, the ...

Hi tony,

When you write to the LCD with 0x00 and 0x04 data (the good trace), how do you know that the data gets written? Deos the cursor on the LCD03 turn off?

Hi tony,

It is a good idea to play with the pull up resistors, since you are playing with quite a different situation than normal for your I2C (you have level shifting). But then when you send the address 0xC6, followed by 0x00, the LCD was able to ACK properly...

Can you please tell more about ...

Hi tony,

Does the waveform on the 5V side look the same as the 3V side? It would have been nice if you showed it as well. From the waveforms you sent, I can tell that you are sending 0xC6, then 0x00, then 0x04 for the good one, and for the bad one 0xC6, 0x00, 0x05 but then can't pull the signal low ...

Hello Wayne,
It'll be great if you will share your basic PIC code. If you please email tech support tlam@matrixorbital.ca, he can post your code in our application note section.
Thank you very much.

Hi Wayne,

Thank you for your post.

If you will be connecting the LK162-12 straight to the 16F877, then yes, you need to get the module to the TTL mode, which entails desoldering the RS232 connecttions, and soldering the TTL connections.

The unit worked before (receive only) because of a (probably ...

Hi tony,

It sounds like the problem is on the Linux source code end. The PK162-12 is doing what it is told; it does not decipher the data it is sent, so it does not know the difference between 'B' and 'A'. Since it does display at least one 'A', this hints that it is not the module that causes the ...

Hello tony,

Thank you for your post.

This problem that you encounter happens when both the PK162-12 and LCD03 are connected to your host controller? How about when only one at a time is connected?

With I2C, bit 0 is the read/write bit, this is the only thing I can think of that can be associated ...

Hello N@boleo,

Thank you for your post. Unfortunately we are only looking at getting displays with European character set right now. It is most likely that what you have only has Japanese character set.

If you need displays with European characters, you can custom order for that, as I was told by ...

Hello ehrnam45,
Thank you for your post.
I wonder about plain characters, if you send in any text, where do they appear? Please send the characters many times until the display wraps and scrolls.

Hello kfaria,
Too bad. But another option that I can think of is connecting a fet at the output of the GPO, the logic will be different but then it can definitely handle the requirements for your beeper. If you want to explore that option, I can help you with that.
Good luck.

Hello kfaria,

Thanks for your post.

First of all, the VK204-25 modules do not have open drain GPOs. The GPOs on the VK204-25 can only source or sink 20mA at 5V. We offer open drain GPOs (called advanced GPOs) on our USB modules. And these open drain GPOs are limited to 12V, 1A, which is ...

Hello kalbanowski,

I wonder about the cable that you use to power and communicate with the Xboard.

Hi dannysauer,

I was going to say query the display until I read the last part of your post. Yes, the best thing to do is to query the display. Say for example, send cmd 254 55 and it should reply its module type which is 0x0F for the VK204-25 that you have. This of course is an indication that it ...