Mega + MAX7456 Breakout

Development Boards MicroMod
1

Hi all. I’m horribly stuck with this breakout and wonder if anyone can offer some insight.

I have it hooked up to ports 50-53 and INT0 (D2) and am using the code supplied in the thread http://www.arduino.cc/cgi-bin/yabb2/YaB … 4359/59#59 over at arduino.cc.

As you can see described in that post from myself, I can get video pass-through working fine - I jsut can’t generate any OSD and the module seems to loose sync regularly untill you touch near the GND pin on the connector block.

I dont have any pullups or other hardware - just the breakout going to a breadboard going to the pins on the arduino. From what I could makeout from the Schematics, everything is onboard and I should be able to generate an OSD by now!! :slight_smile:

Any tips or suggestions from anyone that has used this board succesfully would be massively appreciated.

Thanks in advance!

Adrian

2

bump

I’ve tried with a 10k resistor tied between reset and V+ as a suggestion from the arduino.cc forums, but still no luck.

3

Hello, my problem my problem is over here.

i write code for spi interaction http://paste.org/pastebin/view/14078

ic can display OSD in internal sync or video from input in external sync (OSD I think must be present but not)

The problem - i cant read registers - read_reg allways return 0

OSD does not display in ext. sync (may be problem in black level - i must read default value set bit and next reset bit? but i cant read anything)

when video dark i can see grid on it but without any leters

any ideas?

Arduino 0017

Arduino Duemilanove

Self maded max 7456 brakeout

4

hehehe i change ntsc → pal and can see OSD in external sync mode

but steel cant read registers

5

looking at your code i have not found anything glaringly wrong. your spi for loops go backwards, but you correct that with your bit_mask array being reversed. you have the MSB of the address set when reading from the registers, which is good.

the one thing i would suggest is to try and use the spi hardware instead of bit-banging it. take a look at http://www.arduino.cc/en/Tutorial/SPIEEPROM

6

Hi,

I can display OSD.

But, I also can’t read the SPI register. Have you solved this problem?

I really need to read the register.

Thank you.