I am continuing my radio frequency work so that I have the tools and skill to know what I am looking at and why it doesn't work if that is the case. I wanted I2C test system, but I didn't want to completely redesign so I search. One part is here at "Paint Your Dragon" and I am using that to control the tuner to scan frequencies. I was surprised that video has I2C, but I sometimes feel I hardly know anything yet and I study all day, 7 days a week.
As they say on the site, this is not for the clumsy or faint of heart. A scratch monkey is mandatory.
And from this to a ZigBee.
Pin | Name | Function |
---|---|---|
1 | RED | Red video |
2 | GREEN | Green video |
3 | BLUE | Blue video |
4 | n/c | not connected |
5 | GND | Signal ground |
6 | RED_RTN | Red ground |
7 | GREEN_RTN | Green ground |
8 | BLUE_RTN | Blue ground |
9 | VDC | 5 VDC supply (fused) |
10 | GND | Signal ground |
11 | n/c | not connected |
12 | SDA | DDC / I2C data |
13 | HSYNC | Horizontal sync |
14 | VSYNC | Vertical sync |
15 | SCL | DDC / I2C clock |
You would have thought that I would have noticed this before! I guess I spaced the fact because it never existed with the original VGA spec I would guess.
The I2C interface wasn't available on the original VGA connector definition, but has been added by the VESA DDC2 definition.
This was at Maxim, but I was discovering something about a 4 pin SMB temperature sensor LM90 which showed up while doing "sensors".
The I²C bus and the SMBus are popular 2-wire buses that are essentially compatible with each other. Normally devices, both masters and slaves, are freely interchangeable between both buses. Both buses feature addressable slaves (although specific address allocations can vary between the two buses). The buses operate at the same speed, up to 100kHz, but the I²C bus has both 400kHz and 2MHz versions. Obviously, complete compatibility between both buses using all devices is ensured only below 100kHz.
How is a person ever supposed to be up on all this stuff? There is so much hardware that it exceeds human capacity to coordinate. Something has to be slipping between the cracks.
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