I tried the 4.7K pull up resistors, but that didn't work.
There is another document on the Melexis site, I'll post the address later, it has "preliminary" stamped all over it, but it does look hopeful.
I'm going to have another go at it when I get my Tektronics storage CRO home, I think I'll have more luck.
On thing to bare in mind is SparkFun has an evaluation board for the MLX90614http://www.sparkfun.com/products/9813
If you have a look at the schematichttp://www.sparkfun.com/datasheets/Sensors/Temperature/ir_eval-v14.pdf
They have just hooked the sensor up to the I2C port, no pull ups!
Unfortunately the link on github is broken, so I've not been able to download their source.
Has anyone found out why using the i2cmaster library prevents the UART working?
As a few people have pointed out, even a simple "Hello World" no longer works on the serial monitor!
The PWM output is going to be a "chicken and egg" problem, you'll have to make it work over I2C to set it up!
As I'm going to use this sensor in my "tricorder" thing, I was going to mount it in a "wand", along with some gas sensors.
My idea is to use a separate ATMEGA in the wand and communicate back to the main unit via serial link.
I already have 10 devices on my I2C bus, an HMC6352 digital compass, a DS1307 RTC and 8 24LC256 EEPROMS, I'll also have a temperature and humidity sensor when it arrives, that'll make 11, 12 if I put my uM-FPU V3 on the I2C bus, but I think I'll keep that on the SPI bus along with my MPL115A.
From what I've read SMB and I2C devices are going to be "difficult" to have on the same bus.
So a dedicated controller in the "wand" seems like a good idea.
I've already ordered a few ATmega328's pre-programmed with the Arduino bootloader, I've found the keypad library a bit "twitchy" when you have a lot of stuff going on.
So I was going give my keypad it's own controller to scan the keys, make the key press "beep" and do some other stuff.
This project is taking on a life of it's own!
I'll have to start documenting it now it has the beginnings of a case.
And before you ask, yes, my Mega still has a few port pins I'm not using, yet.