RAK11720 Schematic

LPWAN Modules / EVBs
1

Hello,
We recently bought a bunch of modules as samples for new projects, intended to be used mostly as a LoRa point to point radios with a custom firmware, but in the case of the RAK11720, I cant find the internal schematic anywhere to start the development of a low level firmware. Would it be possible to get it?. Thanks.

2

Welcome to the forum @lfw

Are you writing your firmware with the Ambiq SDK directly?

Did you look into our RUI3 API to create custom firmware for the RAK11720? It includes the complete LoRa drivers and LoRaWAN stack which makes it easy to write a custom firmware. In addition it has an AT command interface that makes setup of a device easy.

The schematics of our WisDuo modules are proprietary, but I can give you the pin assignments for the connection between the Apollo3 and the SX1262:

SX1262 Signal Apollo3 IO
SPI CLK M1SCL_M1SCK_NCE8_SCCCLK_TX1_GP8
SPI MISO M1SDA_M1MISO_NCE9_SCCIO_RX1_GP9
SPI MOSI TX1_M1MOSI_NCE10_PDMC_RTS1_GP10
SPI NSS ADCSE2_NCE11_CT31_SINT_CTS1_RX0_PDMD_GP11
DIO1 ADC1N_NCE15_RX1_PDMD_EXXT_SWDIO_SWO_GP15
BUSY ADCSE0_NCE16_TRG0_SCCRST_CMPI0_TX0_RTS1_GP16
RESET CMPR1_NCE17_TRG1_SCCCLK_RX0_CTS1_GP17
Antenna power CMPI1_NCE18_CT4_RTS0_ATST2_TX1_SCCIO_GP18

For the SX1262 settings:
DIO3 is the TCXO voltage supply
DIO2 is controlling the antenna switch direction
SX1262 is setup for DC/DC usage

3

Thanks, I was asking for the schematics because they were available for all the other WisDuo modules we bought in the doc site, but the pin assignment should be enough.

Yeah, probably we will be writing the firmware directly to the MCU using Ambiq SDK. I did look into the RUI3 API, and would definitely use it if we were provided with binaries and headers to use within our code/compiler, but as far as I could see its all Arduino extensions based, which is not ideal for the scope of our work. Nothing is set yet though.

4

We have released the schematics for some of our older WisDuo modules which are EOL. But for the latest modules like the RAK3172 and RAK11720 they are not available.

For RUI3, we are using Arduino as an easy to use “IDE”, and we added Arduino API calls as an easy way to create code that can be compiled for any of our WisDuo modules with RUI3 firmware.

But I understand that it is not suitable for all uses.
Personally I am writing RUI3 code on Visual Studio Code, using the Arduino-CLI to compile and flash.

5

Hi @beegee ,
i am a vscode cmd person as well . can you share your setup as well?
i want to know how do you use the arduino BSP and compile arduino sketches using cli

6

Welcome to the forum @rdre

The installation guide for VSC is in our documentation center.
For easier access to the compiled files, I add a path for the output in the arduino.json file (this file is created by the Arduino Extension when you open a project).
Here is an example:

{
    "configuration": "debug=l0,supportat=1",
    "board": "rak_rui:stm32:WisDuoRAK3172EvaluationBoard",
    "port": "COM33",
    "sketch": "RUI3-LowPower-Example.ino",
    "output": "build"
}