Bonsoir Mathias,
Attached some pics that should get you going before it arrives. Had to use the phone because someone borrowed my serial interface for the scope.
The first one shows the setup: no pull-ups and long wires. Notice that I connect DOS to the Aref of the arduino.
The second one is some data. It's 4 pics combined because I'm only allowed to upload 4 attachments here.
1. When the sensor is fully exposed to light the levels are not equal, they're one of 2 values. The odd ones are always the same, the even ones are always the same. This is because the chip uses 2 shift registers to push analog data out, these 2 registers are connected to odd or even CCD elements and they're not 100% identical. The minimum voltage is ~1.5V DC, when the sensor is saturated with light
2. This is with the sensor completely covered with a box, minimum light. Max voltage ~3.0V
3. I placed 2 cut pieces of ribbon cable on the sensor. The first one overlaps with S1, the second one is somewhere at 2/3
4. Long exposure over t, I marked the location of S1 (yellow arrow) to show the start. The blue circles show shadow cast by the 3 wires that hang over the sensor. This is with a box with a slit over the setup.
Hope this helps,
Fred