Connecting and FTDI Adapter to the UART on MV Cam

OpenMV Products
1

I want to be able to communicate with the MV Cam via serial with an FTDI serial to USB adapter.
I have the FTDI connected to the UART serial pins on the Cam.

The issue is that the Windows Device Manager reports that the MV Cam AND the FTDI are both on the same COM port! Not sure why that is because each should be on different ports??
How is this issue resolved?

Thanks…

2

This should not be the case. Both devices have different usb PIDs and VIDs. Please check what you are doing carefully.

3

We’ll, what else should I check?

The configuration is MV cam connected to pc via USB.
The ftdi adapter connected to a different USB on the pc.

Device manager shows both on Com5.

If I just connect MV cam, it’s on Com5.
If I just connect the ftdi, it’s on Com5.

Both connected show on Com5.

Strange. Any examples showing both the ide and ftdi connected simultaneously, but on different com ports?

4

Windows can’t allocate two devices on the same COM port.

Can you post a screen shot of the device manager list?

5

Here is the Device Manager:
Com Port Issue.png

6

I used a different FTDI Adapter and this one shows up on COM8. I’m not sure why the other adapter wants to show up on the same COM port as the MV Cam??

Anyway, now that the other FTDI adapter is on COM8 I have it connected to the UART pins on the MV CAM.
I have PuTTY Serial terminal running on COM8 at 115200 baud.

Here is the test script that I am running:

import time
from pyb import UART

# Always pass UART 3 for the UART number for your OpenMV Cam.
# The second argument is the UART baud rate. For a more advanced UART control
# example see the BLE-Shield driver.
uart = UART(3, 19200)

while(True):
    uart.write("Hello World!\r")
    time.sleep_ms(1000)

This issue is that there is NO data coming from the MV CAM displaying on PuTTY.
Why is that?

Thanks…

7

I was connected to UART 1 rather than UART 3.
I changed to code to connect to UART 1 instead.
That works!

I guess there was some confusion about which UART to use.

As far as the COM5 issue, I still don’t know why it’s on the same port as the MV Cam, but this other FTDI adapter on COM8 seems to work OK.

Do you think there is a hardware conflict with certain FTDI adapters working with the MV Cam?

Thanks…

8

Please use the UART with 115200 and timeout_char=1000 as arguments.

9

Please use the UART with 115200 and timeout_char=1000 as arguments.

10

Regarding two COM5s… that’s just straight up a serious error in windows on your PC. The OpenMV Cam has a different PID/VID than FTDI.

11

Double check the pin out, and make sure TX->RX and RX->TX and GND->GND

12

What I will do, when I get a chance is connect both the FTDI and the MV Cam to my laptop and see if both show up on the same COM port.

I’ll post here with results.

Thanks…

13

Actually I was replying to the UART issue not sending data, didn’t refresh the post.