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Understanding VL-GM2-8CAM-RPI22 Adaptor with Jetson Orin Nano

Overview

This article mainly describes the status of the VL-GM2-8CAM-RPI22 adaptor and how to use the additional 20-pin connector.

LEDs

The VL-GM2-8CAM-RPI22 adaptor has three LED indicators, as shown in picture below. The blue LED on the right is the power indicator, and the two green LEDs on the left are the lock indicators for the upper and lower Deserializer, respectively.

Power Selector

The VL-GM2-8CAM-RPI22 adaptor can support multiple input power, accepting 12V from the DC jack or 5V from the additional pin connector.

Switching the power input is achieved via J15. By default, J15 is connected to 1-2 with a 12V input power supply. To make the input power supply 5V, J15 needs to be connected to 2-3.

warning

The 5V input power supply only supports a maximum current of 2A. If you want to connect multiple or eight VLS-GM2 cameras, we still recommend using a 12V input power supply.

12V

5V

Additional 20 Pin Connector

When using TechNexion VL-GM2-8CAM-RPI22 adaptor, it has an additional 20 pin connector that can be connected to the 40 pin connector of the Jetson Orin Nano.

How to connect Orin Nano

Adaptor [Pin Num]Orin Nano [Pin Num]
5V [2]5V [2]
5V [4]5V [4]
GND [6]GND [6]
PDB1 [7]GPIO09 [7]
GND [9]GND [9]
INTB2 [11]UART1_RTS [11]
INTB1 [12]I2S0_SCLK [12]
PDB2 [13]SPI1_SCK [13]
GND [14]GND [14]
EXT_SYNC_IN [19]GPIO12(PWM) [15]
GND [20]GND [20]

In the adaptor, PDB1/2 are the power down pins of the Deserializer, which should be high normally. INTB1/2 are the error pins of the Deserializer, which will be high when an error occurs. EXT_SYNC_IN is the deserializer's external frame sync signal pin, which can be used with the fsync-external device tree. Users can input a PWM signal to synchronize the two deserializers.

tip

If you don't connect any pins from Jetson Orin Nano 40 pin connector to adaptor additional 20 pin connector, the deserializer will still work. The difference is that PWDN is always high, you need to manually cycle power to the adapter when the Jetson Orin Nano restarts.

External Frame Sync Singal

The pin number 15 is PWM0 on the 40 pin connector of the Jetson Orin Nano.
You can use the following shell script to set PWM0 to a 30Hz signal with a 50% duty cycle.

echo 0 > /sys/class/pwm/pwmchip0/export
sleep 0.1
echo 33333333 > /sys/class/pwm/pwmchip0/pwm0/period
echo 16666666 > /sys/class/pwm/pwmchip0/pwm0/duty_cycle
sleep 0.1
echo 1 > /sys/class/pwm/pwmchip0/pwm0/enable

Troubleshooting

  • Host MIPI CSI2 can't get image from GMSL2

    You can use I2C commands to reset the serializer MIPI channel data to ensure MIPI data alignment. The example is as follows.

    I2CBUS_0=9
    SER_0=0x31
    SER_1=0x32
    SER_2=0x33
    SER_3=0x34

    echo '[ INFO ] Reset serializer index 0 to 3 mipi rx'
    i2ctransfer -f -y $I2CBUS_0 w3@$SER_0 0x03 0x30 0x48
    i2ctransfer -f -y $I2CBUS_0 w3@$SER_1 0x03 0x30 0x48
    i2ctransfer -f -y $I2CBUS_0 w3@$SER_2 0x03 0x30 0x48
    i2ctransfer -f -y $I2CBUS_0 w3@$SER_3 0x03 0x30 0x48
    i2ctransfer -f -y $I2CBUS_0 w3@$SER_0 0x03 0x30 0x40
    i2ctransfer -f -y $I2CBUS_0 w3@$SER_1 0x03 0x30 0x40
    i2ctransfer -f -y $I2CBUS_0 w3@$SER_2 0x03 0x30 0x40
    i2ctransfer -f -y $I2CBUS_0 w3@$SER_3 0x03 0x30 0x40

    I2CBUS_1=10
    SER_4=0x41
    SER_5=0x42
    SER_6=0x43
    SER_7=0x44

    echo '[ INFO ] Reset serializer index 4 to 7 mipi rx'
    i2ctransfer -f -y $I2CBUS_1 w3@$SER_4 0x03 0x30 0x48
    i2ctransfer -f -y $I2CBUS_1 w3@$SER_5 0x03 0x30 0x48
    i2ctransfer -f -y $I2CBUS_1 w3@$SER_6 0x03 0x30 0x48
    i2ctransfer -f -y $I2CBUS_1 w3@$SER_7 0x03 0x30 0x48
    i2ctransfer -f -y $I2CBUS_1 w3@$SER_4 0x03 0x30 0x40
    i2ctransfer -f -y $I2CBUS_1 w3@$SER_5 0x03 0x30 0x40
    i2ctransfer -f -y $I2CBUS_1 w3@$SER_6 0x03 0x30 0x40
    i2ctransfer -f -y $I2CBUS_1 w3@$SER_7 0x03 0x30 0x40