Modifying 120deg Viewing Angle Infrared Rear View Camera
by bbarenz in Circuits > Sensors
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Modifying 120deg Viewing Angle Infrared Rear View Camera
These cameras can be purchased from ebay for a little as $15. They are great for security cameras as they have a wide viewing angle and clear image however out of the box the camera comes with a trapezoidal grid superimposed on the video signal and the video image mirrored. These instructions will show how to disable the superimposed image and reverse the video signal.
Disable superimposed image:
First step is to expose the circuit board and locate the SOIC-8 EEPROM (Microchip 24C04A) IC as shown in figure 1. Note that this may look different for each camera. (I had 2 identical model cameras with different circuit boards)
Pin-5 is the serial data connection (SDA) which programs the trapezoidal image on startup. Use a solder iron to pull up this pin as shown in figure 1. Note, if the image is ever desired one could place a switch on these connections however the distance would be limited due to I2C standards.
At this point power the unit up to verify the superimposed image has been removed. If the image is still present check for a small bridge between the pin and the pad or try removing the pin entirely.
Reversing Video signal:
The PC1030D image sensor is actually a very feature rich sensor. The manufacturer has a built in image reversing feature by placing logic 0 or 1 on a data pin. Depending on the circuit board this pin may be accessible from the back of the board however in my case I had one that was and one that was not. The green wire in figure 1 is connected to the reversing pin and 3.3V. Some models also have an external wire for this so check the instructions before completing this step.
If you model does not already have a wire for this or it does not look exactly like the image in figure 1 you will need to access the pin directly from the PC1030D image sensor. Remove the 2 small screws that retain the lens housing. DO NOT TOUCH THE SENSOR. Oils from your skin will smear the image and attempts to clean it will result in scratches. Figure 2 shows the front of the image sensor.
Unfortunately, no discernible markings to indicate a “pin1” (which is in the middle of the chip) could be found, however the image sensor itself does help indicate pin position. Rotate the camera until the image sensor looks the same as figure 2. The orange distance measure indicates the sensor is slightly more to the right. Also, note the difference in the gold wires from the orange and green circles. Use these as road marks to orient your sensor. Once it is in the same orientation as figure 2, the pin you want is the third in from the left as indicated by the meter probe. You have two choices from this point; either carefully solder a small wire to the pin or try to locate this pin on the other side of the board using a continuity meter. If you solder to the pin, make sure to cut a very small notch out of the lens housing to make room for the wire. A fraction of a millimeter will cause the camera to be out of focus when reassembled. If the image is blurry after completion this is the likely cause. Solder the other end of the wire to the 3.3V pin.
Reassemble the lens housing using very little torque on the screws as they strip easily. Now, power the camera up and confirm operation. If the image is not reversed check the connections and make sure there are no solder bridges between the adjacent pins on the image sensor.
Additional Note:
If the camera will be hard wired and the composite connectors removed it is important to know the 3.3V voltage regulator is located in the wire as shown in figure 3.
It is disguised as a ferrite connection but inside is a linear 3.3V regulator. This may not be true for all models however take precaution before removing.
Disable superimposed image:
First step is to expose the circuit board and locate the SOIC-8 EEPROM (Microchip 24C04A) IC as shown in figure 1. Note that this may look different for each camera. (I had 2 identical model cameras with different circuit boards)
Pin-5 is the serial data connection (SDA) which programs the trapezoidal image on startup. Use a solder iron to pull up this pin as shown in figure 1. Note, if the image is ever desired one could place a switch on these connections however the distance would be limited due to I2C standards.
At this point power the unit up to verify the superimposed image has been removed. If the image is still present check for a small bridge between the pin and the pad or try removing the pin entirely.
Reversing Video signal:
The PC1030D image sensor is actually a very feature rich sensor. The manufacturer has a built in image reversing feature by placing logic 0 or 1 on a data pin. Depending on the circuit board this pin may be accessible from the back of the board however in my case I had one that was and one that was not. The green wire in figure 1 is connected to the reversing pin and 3.3V. Some models also have an external wire for this so check the instructions before completing this step.
If you model does not already have a wire for this or it does not look exactly like the image in figure 1 you will need to access the pin directly from the PC1030D image sensor. Remove the 2 small screws that retain the lens housing. DO NOT TOUCH THE SENSOR. Oils from your skin will smear the image and attempts to clean it will result in scratches. Figure 2 shows the front of the image sensor.
Unfortunately, no discernible markings to indicate a “pin1” (which is in the middle of the chip) could be found, however the image sensor itself does help indicate pin position. Rotate the camera until the image sensor looks the same as figure 2. The orange distance measure indicates the sensor is slightly more to the right. Also, note the difference in the gold wires from the orange and green circles. Use these as road marks to orient your sensor. Once it is in the same orientation as figure 2, the pin you want is the third in from the left as indicated by the meter probe. You have two choices from this point; either carefully solder a small wire to the pin or try to locate this pin on the other side of the board using a continuity meter. If you solder to the pin, make sure to cut a very small notch out of the lens housing to make room for the wire. A fraction of a millimeter will cause the camera to be out of focus when reassembled. If the image is blurry after completion this is the likely cause. Solder the other end of the wire to the 3.3V pin.
Reassemble the lens housing using very little torque on the screws as they strip easily. Now, power the camera up and confirm operation. If the image is not reversed check the connections and make sure there are no solder bridges between the adjacent pins on the image sensor.
Additional Note:
If the camera will be hard wired and the composite connectors removed it is important to know the 3.3V voltage regulator is located in the wire as shown in figure 3.
It is disguised as a ferrite connection but inside is a linear 3.3V regulator. This may not be true for all models however take precaution before removing.