# Some notes on using VietArduino board

[https://github.com/productmakerlabvn/Vietduino-WiFi-BLE-ESP32/blob/main/README.md](https://github.com/productmakerlabvn/Vietduino-WiFi-BLE-ESP32/blob/main/README.md)

Some Problems on macOS when trying with this board (you only be stupid once!)

## First problem - wrong wiring causing unable to upload software into the board

* ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1750893793412/eb2eb0d0-fd77-4161-9bb4-41e6afef07fd.png align="center")
    
    This was the error
    

```plaintext
Sketch uses 904416 bytes (69%) of program storage space. Maximum is 1310720 bytes.
 Global variables use 45788 bytes (13%) of dynamic memory, leaving 281892 bytes for local variables. 
Maximum is 327680 bytes. esptool.py v4.8.1 
Serial port /dev/cu.usbserial-10 Connecting...................................... 
A fatal error occurred: Failed to connect to ESP32:
 No serial data received. 
For troubleshooting steps visit: https://docs.espressif.com/projects/esptool/en/latest/troubleshooting.html 
Failed uploading: uploading error: exit status 2
```

Fixed by remove all wiring and troubleshoot one-by-one

## Second error - Flashing error after removing wiring

```plaintext
Connecting......
Chip is ESP32-D0WD-V3 (revision v3.0)
Features: WiFi, BT, Dual Core, 240MHz, VRef calibration in efuse, Coding Scheme None
WARNING: Detected crystal freq 41.01MHz is quite different to normalized freq 40MHz. Unsupported crystal in use?
Crystal is 40MHz
MAC: b8:d6:1a:be:a2:40
Uploading stub...
Running stub...
Stub running...
Changing baud rate to 921600
Changed.

A fatal error occurred: Unable to verify flash chip connection (Packet content transfer stopped (received 7 bytes)).
Failed uploading: uploading error: exit status 2
```

Fixed by changing upload speed to **115200**

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1750894040744/d0f02f9b-53c4-4039-b38e-3afc48a22775.png align="center")