lora-file-transfer-example - transfer files from mbed-os block device (i.e. SD…

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wayne roberts / Mbed OS lora-file-transfer-example

transfer files from mbed-os block device (i.e. SD card) over LoRa radio.

radio chip selection

Radio chip driver is not included, allowing choice of radio device.
If you're using SX1272 or SX1276, then import sx127x driver into your program.
if you're using SX1261 or SX1262, then import sx126x driver into your program.
if you're using SX1280, then import sx1280 driver into your program.
If you're using NAmote72 or Murata discovery, then you must import only sx127x driver.

This program uses mbed serial terminal at 115200 8N1.
Files (on SD Card) are transferred between two LoRa devices.
Use ? question mark to see available commands on serial terminal.
Send file to other side using send /fs/somefile, then use cmp /fs/somefile to compare the file on the other side of radio link with local file with same name.
Use cmp to test radio link.

rm command to delete files must not include /fs/ directory prefix, filename only.
send and cmp require /fs/ directory.

sx1280 thruput

bytes/sec	sf12	sf11	sf10	sf9	sf8	sf7	sf6	sf5
1600KHz	276	482	1081	1887	3277	5365	6400	12000
800KHz			529	970	1720	2800	4766	6500
400KHz						1465	2265	4033

sx126x thruput

bytes/sec	sf12	sf11	sf10	sf9	sf8	sf7	sf6	sf5
500KHz		207	381	706	1257	2154	3570	5608
250KHz		103	193	344	641	1114	1887	3064
125KHz			97	173	324	547	972	1607

sx127x thruput

sx126x recommended at 500KHz bandwidth.

bytes/sec	sf12	sf11	sf10	sf9	sf8	sf7
500KHz	111	207	385	697	1220	2050
250KHz	48.7	103	192	345	632	1115
125KHz	24.2	44	97	151	313	552
62.5KHz	12.2	22.1	39.4	86	157	276

SD Card

SD card driver must be enabled in mbed_app.json with the line "target.components_add": ["SD"]
Pins for SD card connection can be overridden as shown in mbed_app.json.
The default pin configuration for SD card is found in mbed_lib.json in mbed-os/components/storage/blockdevice/COMPONENT_SD/.
If no pin configuration exists in this mbed_lib.json, or needs to be changed, the included mbed_app.json is example pin declaration for SD card.

FAT filesystem is only used in this project for demonstration purpose; for easily copying files to SD card.
However, for production projects, LittleFileSystem needs to be used instead for reliability and wear leveling.

Platforms such as K64F have SD card slot already.
See all boards with arduino shield connector and SD card here. (arduino connector needed for LoRa radio board)
...but if you want to use nucleo board: /media/uploads/dudmuck/nucleo_sdcardqtr.png