# Reduced Resolution WVGA modes for the MT9V034

**URL:** <https://forums.openmv.io/t/reduced-resolution-wvga-modes-for-the-mt9v034/1382>\
**Category:** OpenMV Boards\
**Created:** [August 14, 2019, 3:01pm UTC](https://forums.openmv.io/t/reduced-resolution-wvga-modes-for-the-mt9v034/1382 "2019-08-14T15:01:33Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![ecdm2](https://avatars.discourse-cdn.com/v4/letter/e/e495f1/32.png) [@ecdm2](https://forums.openmv.io/u/ecdm2)\
**Post date:** [August 14, 2019, 3:01pm UTC](https://forums.openmv.io/t/reduced-resolution-wvga-modes-for-the-mt9v034/1382/1 "2019-08-14T15:01:33Z")

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Hello

I’d like to use the full width of the Global Shutter (MT9V034) sensor at reduced resolution for AprilTag detection but can’t see a QWVGA or QWVGA2 mode.

Is it possible to do this ?

If I need to write to the camera registers can you give me any tips / pointers ?

Ed

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**Author:** ![kwagyeman](https://yyz1.discourse-cdn.com/flex029/user_avatar/forums.openmv.io/kwagyeman/32/4_2.png) [@kwagyeman](https://forums.openmv.io/u/kwagyeman)\
**Post date:** [August 14, 2019, 3:48pm UTC](https://forums.openmv.io/t/reduced-resolution-wvga-modes-for-the-mt9v034/1382/2 "2019-08-14T15:48:32Z")

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Um, you’ve have to edit the firmware to do this. It’s pretty easy to. Once you have the build system setup just add a new resolution mode and a QSTRING for it and you’re done:

[https://github.com/openmv/openmv/blob/master/src/omv/sensor.c#L36](https://github.com/openmv/openmv/blob/master/src/omv/sensor.c#L36)  
[https://github.com/openmv/openmv/blob/master/src/omv/sensor.h#L42](https://github.com/openmv/openmv/blob/master/src/omv/sensor.h#L42)  
[https://github.com/openmv/openmv/blob/master/src/omv/py/py\_sensor.c#L680](https://github.com/openmv/openmv/blob/master/src/omv/py/py_sensor.c#L680)  
[https://github.com/openmv/openmv/blob/master/src/omv/py/qstrdefsomv.h#L195](https://github.com/openmv/openmv/blob/master/src/omv/py/qstrdefsomv.h#L195)

The driver can deal with any resolution you wan to use (make sure the resolution is divisible by 2/4 however otherwise you’ll get weird AHB transfer size minimum issues related to DMA on the H7).

See the github wiki for how to build the firmware.

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<div class="post-metadata">

**Author:** ![ecdm2](https://avatars.discourse-cdn.com/v4/letter/e/e495f1/32.png) [@ecdm2](https://forums.openmv.io/u/ecdm2)\
**Post date:** [August 14, 2019, 5:24pm UTC](https://forums.openmv.io/t/reduced-resolution-wvga-modes-for-the-mt9v034/1382/3 "2019-08-14T17:24:12Z")

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Thanks - that all looks pretty straightforward.

Ed