TDA4AH-Q1: Auto Exposure tuning for AR0341

Ajay Jose

Part Number: TDA4AH-Q1

Tool/software:

Hi Experts,

I am working on setting up the AR0341 image sensor with the TDA4H hardware platform using the SDK version 09_02_00_05 and HLOS: Linux.

I have created the XML files for the AR0341 sensor using the default DCC tool. Following that, I am attempting to tune the camera's Auto Exposure (AE) using the guidance from the following link:

[FAQ] AM62A7: How to Set the Minimum/Maximum Exposure Time and Analog Gain for 2A Algorithm? - Processors forum - Processors - TI E2E support forums

However, I am encountering an issue where the output image (VISS image) appears very dark (underexposed).

Questions:

1. Is the guidance provided in the linked forum post applicable to tuning the Auto Exposure (AE) for the TDA4H platform with the AR0341 sensor?Specifically, I am trying to adjust the minimum/maximum exposure time and analog gain, but since the AR0341 sensor cannot control the analog gain from the host side, I am adjusting only the exposure time.

2. Regarding exposure time conversion:
I observed that for other sensors, such as the AR0820, there is a specific conversion logic (e.g., in the function `AR0820_SetAeParams()`) before sending the exposure time to the sensor.
Does a similar conversion need to be done for the AR0341? If so, could you provide guidance on the conversion process or the formula used to convert the exposure time into the format expected by the AR0341 sensor?

Example :For AR0820 sensor

filename :iss_sensor_ar0820.c

function name:AR0820_SetAeParams()

Thank you,

Ajay Jose

7 months ago

0 Gang Hua 7 months ago

TI__Guru 60780 points

Hi Ajay,

Ajay Jose said:
since the AR0341 sensor cannot control the analog gain from the host side, I am adjusting only the exposure time.

That looks like a limitation of AR0341.

Ajay Jose said:
However, I am encountering an issue where the output image (VISS image) appears very dark (underexposed).

This is related to the gain in AR0341 (analog and digital).
For other sensor, more gain may be allowed in the sensor.
AR0341 may be special in this case.
In general, you should use as much gain in the sensor as possible to get brighter images.

Another thing you may try in VISS is to change GLBCE settings to make output image as bright as possible.
e.g., turn on/off the forward/reverse perceptual LUT on/off combinations to make output image brighter (one on + off combination gives the brightest output).

Ajay Jose said:
Does a similar conversion need to be done for the AR0341? If so, could you provide guidance on the conversion process or the formula used to convert the exposure time into the format expected by the AR0341 sensor?

Yes, this conversion is needed.

It depends on the sensor and your sensor driver settings and we at TI are not able to support.