VD55G1 Differential Mode

[leonardzhang]

Hi there, I'm trying to figure out how to configure VD55G1 monochrome sensor to differential mode (e.g. disruptive mode, event mode) as branded in user manual. However, after going through https://github.com/STMicroelectronics/stm32-mw-camera, I have no clue. Could you help me with this? Thank you.

[ST-Chad]

Hi,

For the event mode, please refer to Appendix G in the user manual. We call it the auto wake-up mode( AWU).

When the event occurs, the sensor will send a signal via the GPIO to the host. The host can then decide the next step, such as waking up the sensor to take a picture or activating other devices to perform certain actions.

I have also attached the sample register configuration for your reference below.

// -----------------------------------------------------------------
// This script has been automatically generated by GPSDK
// 
// For better compatibility between platforms and V2Wreg
// You can force a transfer limit during generation:
// from gpsdk import config
// config.MAX_TRANSFER_SIZE = 64
// -----------------------------------------------------------------

$SCRIPT


SetBank(0x20);


// Set frequencies
WriteAutoIncrement(0x0220, 0x0, 0x1b, 0xb7, 0x0); // (val=12000000) / UI.SENSOR_SETTINGS.EXT_CLOCK.VALUE
WriteAutoIncrement(0x0224, 0x0, 0x8c, 0x86, 0x47); // (val=1200000000) / UI.SENSOR_SETTINGS.MIPI_DATA_RATE.VALUE
WriteAutoIncrement(0x0300, 0x40, 0x5); // (val=1344) / UI.STREAM_STATICS.LINE_LENGTH.VALUE
WriteAutoIncrement(0x0300, 0x68, 0x4); // (val=1128) / UI.STREAM_STATICS.LINE_LENGTH.VALUE
// => External clock = 12.00 MHz, Csi frequency = 1200.00 Mbps, Line time = 7.52 us

WriteAutoIncrement(0x0370, 0x0, 0x6); // (val=6) / UI.STREAM_STATICS.AWU_DETECTION_THRESHOLD.INTEGER
WriteAutoIncrement(0x036c, 0x42, 0x11, 0x0, 0x0); // (val=4418) / UI.STREAM_STATICS.AWU_CTRL
WriteAutoIncrement(0x0372, 0xbe, 0x1); // (val=446) / UI.STREAM_STATICS.EXPOSURE_USER_MAX_COARSE_INTEGRATION_LINES.VALUE
WriteAutoIncrement(0x036c, 0x42, 0x11, 0xa8, 0x8); // (val=2216) / UI.STREAM_STATICS.AWU_CTRL.FRAME_LENGTH_FOR_CONVERGENCE
WriteAutoIncrement(0x0312, 0x0); // (val=0) / UI.STREAM_STATICS.EXPOSURE_USE_CASES.ENABLE_MULTI_CONTEXT
WriteAutoIncrement(0x03e4, 0x10, 0x11); // (val=0) / UI.STREAM_STATICS.CONTEXT_NEXT_CONTEXT.CTX0
WriteAutoIncrement(0x03e4, 0x10, 0xf1); // (val=255) / UI.STREAM_STATICS.CONTEXT_NEXT_CONTEXT.CTX3
WriteAutoIncrement(0x03dc, 0x0, 0x0); // (val=0) / UI.STREAM_STATICS.CONTEXT_REPEAT_COUNT_CTX0.VALUE
WriteAutoIncrement(0x03e2, 0x0, 0x0); // (val=0) / UI.STREAM_STATICS.CONTEXT_REPEAT_COUNT_CTX3.VALUE
WriteAutoIncrement(0x0500, 0x0); // (val=0) / UI.STREAM_CTX0.EXPOSURE_MODE.MODE
WriteAutoIncrement(0x050c, 0xa8, 0x8, 0x0, 0x0); // (val=2216) / UI.STREAM_CTX0.FRAME_LENGTH.VALUE
WriteAutoIncrement(0x051d, 0x2); // (val=2) / UI.STREAM_CTX0.GPIO_0_CTRL.Mode
WriteAutoIncrement(0x051e, 0x5); // (val=5) / UI.STREAM_CTX0.GPIO_1_CTRL.Mode
WriteByte(0x0537, 0x00); // (val=0) / UI.STREAM_CTX0.MASK_FRAME_CTRL
WriteAutoIncrement(0x05fc, 0xe3, 0x67, 0x0, 0x0); // (val=26595) / UI.STREAM_CTX3.FRAME_LENGTH.VALUE
WriteAutoIncrement(0x060d, 0x2); // (val=2) / UI.STREAM_CTX3.GPIO_0_CTRL.Mode
WriteAutoIncrement(0x060e, 0xd); // (val=13) / UI.STREAM_CTX3.GPIO_1_CTRL.Mode
WriteByte(0x0627, 0x01); // (val=1) / UI.STREAM_CTX3.MASK_FRAME_CTRL

 

[leonardzhang]

I guess I made it ambiguous. This is what I'm looking for.

[ST-Chad]

This is the frame subtraction function, which is also explained in Appendices B and C.

The difference between them is that Appendix B requires the host to process the subtraction, while Appendix C performs it on the sensor side. Both appendices also include sample code for your reference.

I have attached the sample code to enable the subtraction for you. For more details, please check the sample code in the appendices.

 def enable_normal_internal_BG(self, exposure_mode):
 """
 internal back ground subtraction with single context
 """
 if self.m_bRunning:
 iRet = self.m_dtccm.GrabHold(self.m_iDevID)
 if iRet is None:
 print("GrabHold in internal subtraction failed!")
 
 if exposure_mode == 1:
 self.set_exposure_mode(EXPOSURE_MODE_CTX0, 0x00)
 else:
 self.set_exposure_mode(EXPOSURE_MODE_CTX0, 0x02)

 self.I2CWrite(VT_MODE_CTX0, 1) # VT_MODE = 1 : Subtraction on CTX0 , 0 : Normal Mode
 self.I2CWrite_16(VT_SUB_WAIT_EXPOSURE_LINES, 0) # wait exposure lines between 2 sub-frames
 self.I2CWrite_16(VT_SUB_WAIT_PIXELS, 0) # wait pixels between 2 sub-frames
 self.I2CWrite_16(DARKCAL_PEDESTAL_CTX0, 0)
 self.I2CWrite(GPIO_1_CTRL_CTX0, 2) # GPIO_1 = 2 (Strobe MODE)

 if self.m_bRunning:
 iRet = self.m_dtccm.GrabRestartWithSkip(0, 0, self.m_iDevID)
 if iRet is None:
 print("Restart frame in internal subtraction failed!")
 time.sleep(0.5)

 

[Will_Robertson]

Hi @ST-Chad 

Thank you very much for your explanation "The difference between them is that Appendix B requires the host to process the subtraction, while Appendix C performs it on the sensor side. Both appendices also include sample code for your reference."

Will