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This lesson talks about the working conditions of the camera

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First look at some of the main English signs of the camera circuit

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If you want to find the camera circuit, you can generally search for CAM

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Common English codes for rear cameras are RCM, MCAM, WCAM and TCAM

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The English codes of the front camera are SCAM and FCAM

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By searching these English words, you can quickly find the camera circuit

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Next, let's look at the working conditions of the camera circuit

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The first is the power supply

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Generally there are 3-6 ways of power supplies

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Early camera circuits generally have three power supplies, usually output by the power chip,

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or by the LDO small chip, or by the camera power supply

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The clock signal of the camera, the code identification is generally MCLK

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CLK is the abbreviation of the clock signal, which is output by the CPU to the camera

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It is described in the drawings that the CPU is provided with the camera connector,

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but in fact it is provided with the camera

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Above is the clock signal

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The English code name of reset is generally RESET or RST,

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which is also output to the camera by the CPU

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Control signal, I2C bus, mainly for detection and control of the camera, output to the camera by the CPU

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The I2C bus for all circuits has two wires

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In Android phones, it is generally ISP bar SDA or ISP bar SCL,

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and some also use I2C bar SDA or SCL to indicate

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Generally, the I2C bus has a pull-up circuit

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When repairing, pay special attention to the measurement of the pull-up circuit

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The I2C bus has a voltage of 1.8 volts,

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and the reset voltage also has a voltage of 1.8 volts

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If the voltage of the clock signal is measured to judge the fault, it is not particularly accurate

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But it also has a 0.5 volts to 0.9 volts voltage on it

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Then look at next working condition, the bus

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After the camera captures the image, the image signal is sent to the CPU through the bus

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In Android phones, CSI is usually used instead of MIPI bus

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These are the working conditions of the camera circuit,

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if any of them fails, the camera will not turn on

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That's all for this lesson