# OpenMV H7 Plus : problem with CAN Bus

**URL:** https://forums.openmv.io/t/openmv-h7-plus-problem-with-can-bus/5573
**Category:** OpenMV Boards
**Created:** [March 18, 2021, 5:15pm UTC](https://forums.openmv.io/t/openmv-h7-plus-problem-with-can-bus/5573 "2021-03-18T17:15:01Z")
**Posts on this page:** 6
**Page:** 1

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### Author: ![pal53](https://avatars.discourse-cdn.com/v4/letter/p/6f9a4e/32.png) [@pal53](https://forums.openmv.io/u/pal53)
#### Post date: [March 18, 2021, 5:15pm UTC](https://forums.openmv.io/t/openmv-h7-plus-problem-with-can-bus/5573/1 "2021-03-18T17:15:01Z")

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Dear All,  
I have a simple code sending a CAN Frame, the example one.  
It works fine with CAM H7 and OpenMV CAN shield but not with H7 Plus.  
the source code is the same and I can not see where is the problem.  
The camera H7 Plus is powered with USB and other example are OK.  
Best Regards,  
Patrick from France.

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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: [March 18, 2021, 5:28pm UTC](https://forums.openmv.io/t/openmv-h7-plus-problem-with-can-bus/5573/2 "2021-03-18T17:28:13Z")

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Hi, are you running the latest firmware? The there is no difference between these boards in CAN code.

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### Author: ![pal53](https://avatars.discourse-cdn.com/v4/letter/p/6f9a4e/32.png) [@pal53](https://forums.openmv.io/u/pal53)
#### Post date: [March 18, 2021, 5:42pm UTC](https://forums.openmv.io/t/openmv-h7-plus-problem-with-can-bus/5573/3 "2021-03-18T17:42:07Z")

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Hi,  
Apparently yes, Micropython v1.13-r69 and HAL V1.9.0 for both camera

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### Author: ![iabdalkader](https://yyz1.discourse-cdn.com/flex029/user_avatar/forums.openmv.io/iabdalkader/32/1169_2.png) [@iabdalkader](https://forums.openmv.io/u/iabdalkader)
#### Post date: [March 18, 2021, 6:08pm UTC](https://forums.openmv.io/t/openmv-h7-plus-problem-with-can-bus/5573/4 "2021-03-18T18:08:34Z")

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It could be the different clock…Do you set the same baudrate and sampling point ? What’s on the receiving end ?

```auto
CAN(2, CAN.NORMAL, baudrate=125_000, sampling_point=75)

```

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<div class="post-metadata">

### Author: ![pal53](https://avatars.discourse-cdn.com/v4/letter/p/6f9a4e/32.png) [@pal53](https://forums.openmv.io/u/pal53)
#### Post date: [March 19, 2021, 8:39am UTC](https://forums.openmv.io/t/openmv-h7-plus-problem-with-can-bus/5573/5 "2021-03-19T08:39:21Z")

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It is exactly the same code with  
can = CAN(2, CAN.NORMAL, baudrate=500\_000, sampling\_point=75)  
CPU freq is the same (480, 240, 120, 120)  
I suspect an Hardware problem, either in the camera itself or when I welded the connector to plug the shield but it seems OK.  
Does anyone test the CAN bus with H7 Plus and or without the CAN shield ?

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### Author: ![pal53](https://avatars.discourse-cdn.com/v4/letter/p/6f9a4e/32.png) [@pal53](https://forums.openmv.io/u/pal53)
#### Post date: [March 19, 2021, 9:06am UTC](https://forums.openmv.io/t/openmv-h7-plus-problem-with-can-bus/5573/6 "2021-03-19T09:06:08Z")

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This morning I changed the receiver and it works both for H7 and H7 plus  
I have to understand why it does not with the other receiver,  
but the problem should not come from the H7 Plus.