Whether you are using the revision 01/02 or the newer (in development) revision 03 Node, they are all easily configured via a serial connection.

If you are using the 01/02 Nodes, you will need a UART(TTL) to USB converter to configure it via a serial console. With the 03 Nodes, plugging in the USB will both power it and provide a CDC based serial port which will install automatically in Linux or Windows 8.1/10 as a com port.

To power the Nodes, you will need at least a 3.3V supply @ > 300mA (the 01 node only goes from 3.3-5V whereas the 02/03 Nodes have an input rating of 3.3-20V with reverse battery protection).

You can use any serial console emulator you like with the following serial port configuration:

• Baud Rate – 9600
• Bits – 8
• Parity – None
• Stop Bits – 1
• Flow Control – None

Once connected, you should get the following on boot:

SubPos Node - http://www.subpos.org
fw ver 0.9.9 2015-07-23

eeprom data loaded successfully.

settings loaded successfully.

initialising esp module.

menu:
help - display this menu message.
wizz - guided configuration wizard.
show - show current settings.
hexd - enter pre coded hex data.
dbcn - disable beacons.
ebcn - enable beacons.
norm - set beacon mode normal.
acut - set beacon mode accurate timing.
freq - set beacon mode freq hopping (cyclic).
slat - set latitude.
slng - set longitude.
salt - set altitude.
clre - clear eeprom.
wree - write settings to eeprom.
chan - change beacon channel.

From here it is pretty simple to navigate, just type the command you want to run from the "help" menu and press enter. You can even correct mistakes before executing commands.

When you make changes to settings that need to be written to eeprom to remain persistant on reboot, an asterisk will show in the command area:

*>

To save, just type "wree" to save current settings to eeprom.

The red LED will illuminate when the device is performing critical operations like writing to eeprom. During boot it will stay illuminated until the ESP module initialises. If this stays illuminated for more than 10 seconds, there is an issue communicating with the ESP module. On the 03 firmware, this will automatically try to reinitialise the device, but on older versions, make sure the jumpers are set correctly.

If the red LED continues to stay illuminated on boot, the ESP module may need flashing.