# UART between OpenMV and Arduino Uno

**URL:** <https://forums.openmv.io/t/uart-between-openmv-and-arduino-uno/6500>\
**Category:** OpenMV Boards\
**Created:** [November 2, 2021, 1:57am UTC](https://forums.openmv.io/t/uart-between-openmv-and-arduino-uno/6500 "2021-11-02T01:57:50Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![tnkumar](https://avatars.discourse-cdn.com/v4/letter/t/278dde/32.png) [@tnkumar](https://forums.openmv.io/u/tnkumar)\
**Post date:** [November 2, 2021, 1:57am UTC](https://forums.openmv.io/t/uart-between-openmv-and-arduino-uno/6500/1 "2021-11-02T01:57:50Z")

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In the OpenMV IDE, under Files-\> Examples-\>OpenMV-\>Arduino-\>arduino\_uart.py, I see the below

```auto
# Basic UART communications between OpenMV and Arduino Uno.

# 1) Wire up your OpenMV Cam to your Arduino Uno like this:
#
# OpenMV Cam Ground Pin ----> Arduino Ground
# OpenMV Cam UART3_TX(P4) ----> Arduino Uno UART_RX(0)
# OpenMV Cam UART3_RX(P5) ----> Arduino Uno UART_TX(1)

# 2) Uncomment and upload the following sketch to Arduino:
#

```

My Arduino is powered 5V and I plan to power my OpenMV with 3.7V Lipo

Question  
Can I directly connect the pins as specified in the comments or do I need to level shift?

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**Author:** ![tnkumar](https://avatars.discourse-cdn.com/v4/letter/t/278dde/32.png) [@tnkumar](https://forums.openmv.io/u/tnkumar)\
**Post date:** [November 3, 2021, 6:02pm UTC](https://forums.openmv.io/t/uart-between-openmv-and-arduino-uno/6500/2 "2021-11-03T18:02:24Z")

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Any feedback on this question?

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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:** [November 4, 2021, 3:00pm UTC](https://forums.openmv.io/t/uart-between-openmv-and-arduino-uno/6500/3 "2021-11-04T15:00:19Z")

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You don’t need to level shift. Please read the documentation and notice that all I/O pins are 5V tolerant.

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<div class="post-metadata">

**Author:** ![tnkumar](https://avatars.discourse-cdn.com/v4/letter/t/278dde/32.png) [@tnkumar](https://forums.openmv.io/u/tnkumar)\
**Post date:** [November 4, 2021, 3:29pm UTC](https://forums.openmv.io/t/uart-between-openmv-and-arduino-uno/6500/4 "2021-11-04T15:29:14Z")

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Thanks @kwagyeman - Are the pins 5V tolerant even when the OpenMV Cam is powered by 3.7V LiPo battery? I am concerned not to damage the expensive OpenMV Cam

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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:** [November 4, 2021, 4:02pm UTC](https://forums.openmv.io/t/uart-between-openmv-and-arduino-uno/6500/5 "2021-11-04T16:02:28Z")

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Yes, the camera is at 3.3V normally.

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<div class="post-metadata">

**Author:** ![tnkumar](https://avatars.discourse-cdn.com/v4/letter/t/278dde/32.png) [@tnkumar](https://forums.openmv.io/u/tnkumar)\
**Post date:** [November 4, 2021, 6:01pm UTC](https://forums.openmv.io/t/uart-between-openmv-and-arduino-uno/6500/6 "2021-11-04T18:01:58Z")

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Thanks @kwagyeman