RAK4270 Breakout Board UART Problem

LPWAN Modules / EVBs
1

Hi,
i have a RAK 4270 Board connected via UART to a Raspberry Pi 3B+.

I can recieve Data from the Board but i can not send.

On RAK Board i use RX2, TX2
On Raspberry UART on Pin 8+10 (GPIO 14,15) . In Raspbian it is ttyS0 on miniUART.
Port setup in miniport is: 115200 8N1, no Hardware Flow Control
Bluetooth is disabled and serial console as well.

When i connect 3.3V to the board i recieve some data from the board:

LoRa (R) is a registered trademark or service mark of Semtech Corporation or its affiliates. LoRaWAN (R) is a licensed mark.

RAK4270 version:3.3.0.14
UART1 work mode: RUI_UART_NORMAL, 115200, N81
UART2 work mode: RUI_UART_NORMAL, 115200, N81
Current work_mode:LoRaWAN, join_mode:OTAA, MulticastEnable: false, Class: A
Initialization OK
This Output is only on power up from UART2.

But no echo from my keystrokes when i want send AT Commands
Connection from the Pi to other devices works.
On my scope i can see the keystrokes on TX Line.

Where is my mistake?

3

Welcome to RAK forum @sebastian :slight_smile:

When you send at+version there is no reply? Can you try to update the firmware using this guide Quick Start Guide | RAKwireless Documentation Center

4

Thanks carlowan!
I see no reply of my keystrokes.
Normaly i should see the Echo.

Amazon is on the way with a TTL-USB Adapter. On Friday i can update the firmware.
Thats why i started with the pi…

5

Ok sebastian, once you got the TTL-USB Adapter, it won’t hurt if you will update your firmware :slight_smile:

6

Hi @sebastian
Two things you can try/check:

  1. Try UART1 instead of UART2.
  2. Make sure AT commands sent to the RAK4270 are ending with “\r\n”.
7

Thanks Bernd!
I tried both UART.
At UART2 i get this Boot Message.
On UART1 nothing.

I think the Board can not recieve my output.

8

Solved.
The Linux Minicom Tool not send \r\n correctly.
On Windows with putty or RAK Tool it works well.

Thanks for your Support!

9

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