Imported from GitHub: VioletEternity/BeagleBoneLoRaAdapter · commit 867ef41 · license CERN-OHL-P-2.0

Description

Dual LoRa module adapter for BeagleBone

README

Dual LoRa module adapter for BeagleBone

This PCBA connects widely available LoRa modules based on Semtech SX127x RFIC, such as this module (archive) sold on Aliexpress for less than $3, to the Texas Instruments BeagleBone family of single board computers.

Requirements

The module must have a size of 16 by 16 mm, and have 16 castellated pads with 2 mm spacing; for details, see the Kicad footprint. The module pinout must match the following, viewed from the top:

Pin 1?
ANT		GND
GND		DIO5
DIO3		nRESET
DIO4		nCS
3V3		SCK
DIO0		MOSI
DIO1		MISO
DIO2		GND

These modules do not have a clearly marked pin 1, so the actual pinout may be rotated 180° compared to the above.

See also the bill of materials.

Usage

BeagleBone pinout

The following table lists the BeagleBone pins and their connections:

Radio#	Function	BB pin	CPU pin
radio0	nRESET	P9_15	gpio1[16]
radio0	IRQ	P9_16	gpio1[19]
radio0	nCS	P9_17	gpio0[5]
radio0	SCK	P9_22	gpio0[2]
radio0	MOSI	P9_18	gpio0[4]
radio0	MISO	P9_21	gpio0[3]
radio1	nRESET	P9_25	gpio3[21]
radio1	IRQ	P9_27	gpio3[19]
radio1	nCS	P9_28	gpio3[17]
radio1	SCK	P9_31	gpio3[14]
radio1	MOSI	P9_30	gpio3[16]
radio1	MISO	P9_29	gpio3[15]

Radio 0 is connected to CS0 of SPI0, radio 1 is connected to CS0 of SPI1.

BeagleBone pin mux configuration

To configure BeagleBone pins, run the following commands:

sudo modprobe spidev
sudo chown $USER /dev/spidev*

config-pin P9_15 gpio_pu
config-pin P9_16 gpio_pu
config-pin P9_17 spi_cs
config-pin P9_22 spi_sclk
config-pin P9_18 spi
config-pin P9_21 spi

config-pin P9_25 gpio_pu
config-pin P9_27 gpio_pu
config-pin P9_28 spi_cs
config-pin P9_31 spi_sclk
config-pin P9_30 spi
config-pin P9_29 spi

These commands were tested on Debian 12 (bookworm).

Basic functional test

To perform a basic test of module functionality, install spi-tools and run the following commands:

echo '0: 4200' | xxd -r | spi-pipe -b 2 -d /dev/spidev0.0 | xxd
echo '0: 4200' | xxd -r | spi-pipe -b 2 -d /dev/spidev1.0 | xxd

Both commands should return the following output:

00000000: 0012                                     ..

The number 12 is the module ASIC revision.

Full functional test

Steps for performing a full test of module functionality, including radio transmission and reception, will be provided later.

Revision history

A1 : Initial revision

Terms of distribution

The adapter is covered by the CERN-OHL-P (permissive) license. See LICENSE.txt for details.