Hi,

Please could somebody tell me the size of the mounting holes on the VK162 for both PCBs - for the PK162-12 they were different on each

Can't find this information in the user manual, nor in the Autocad drawing.

Thanks

Hi,

is there any advantage in running the display at a lower brightness setting regards the brightness level - i.e is the 10000 hours applicable to normal default brightness or across the entire range of brightness levels?

Also, I'd assume that having periods where nothing is displayed on the ...

Hello,

I have ended up using a TI PCA9306, a dual bidirectional level translator, which also serves to isolate the capacitance of the 3v3 and 5v sides. That is, it's possible to have another 400pF on the 5v side which can only be a good thing.

This successfully translates the ACK pull-down on the ...

Hi Raquel,

Trace as promised. Trace is of 0xc6 0x00 0x05

Thanks

Tony

Hi Raquel,

no progress yet. I'm waiting for the postman to deliver some Phillips buffer and translation chips. Hopefully will have some conclusions close of play Wednesday.

I *will* remember to post the scope traces tomorrow.

Thanks

Tony

Hi Raquel,

sorry, I must have been confused by what you asked.

I transmitted an odd byte onto the bus that wasn't acknowledged since it wasn't recognised by any slave. The waveform for that looked ok, so the master isn't sending strange stuff onto the bus.

I have got some traces in excel ...

Hi Raquel

When transmitting a ODD value onto the bus, the trace looks fine. However,
I did find this message when googling:
For a 5 volt system, a 1k pullup would be too low. In section 16.1 of the i2c spec (page 39), it says the minimum specified sink current is 3 ma.

This gives 5v/3ma = 1.67K ...

Hi Raquel,

The LCD03 interprets 0x00 as the address of a register into which the 0x04 is written. The 0x04 turns off the cursor, the 0x05 (bad trace) turns on an underline cursor. The display does show the cursor being hidden and replaced.

If I write "0x42" 'B' it appears on the display without ...

Hi Raquel,

the board is a prototype put together by a local electronics company. It uses an ST2378E level translator chip http://www.st.com/stonline/books/pdf/docs/9489.pdf .

Yes, the ACK situation is a bit weird. The master should release SDA after it transmits the last bit and the slave is ...

Hi Raquel,

the VIPER SBC is not 5v tolerant unfortunately (well, not for extended periods).

I'll try and get a trace on the 5v side. I wonder if the VIPER 1k pull-ups are too low a resistance for the other devices to pull to zero for the ACK?

Thanks

Tony

Hi

Hope you don't mind, but thought I'd post some more about the problems I'm having.

I

Hi Raquel,

It's definitely something to do with the level shifter. Operations on the 3v3 side of the i2c work OK, can change the conversion rate on the ADT7461 by writing odd/even values to the register.

Operations on the 5v side fail on odd values. Actual failure appears to be no bus acknowledge ...

Hi Raquel,

the problem occurs when I've got the PK162-12 and the ADT7461. I can't remove the ADT7461 as its soldered onto the board. I've not attached the LCD03 and PK162-12 at the same time.

I believe I'm addressing the PK162-12 properly since I can see the characters output to the display; but ...

Hi,

I've got a couple of display modules (a PK162-12 and an LCD03 http://www.robot-electronics.co.uk/htm/Lcd03tech.htm ).

In fact I've got another 13 PK162-12s that I haven't tested yet.

The boards are attached to the i2c bus of a Arcom VIPER SBC (an ARM PXA255). This board has 1k pull-up ...