microReticulumTbeam/exercises/302_microReticulum_ble_announce_single

Exercise 302: microReticulum BLE announce + SINGLE destination ping-pong

This exercise is the BLE analogue of Exercise 202.

Exercise 301 proved that microReticulum PLAIN packets can cross the ESP32/T-Beam BLE interface. Exercise 302 adds Reticulum identity discovery: each node creates an identity, announces an inbound SINGLE destination over BLE, learns the peer's announced identity and destination hash, then sends encrypted DATA packets to that learned destination.

BLE GATT connection -> Identity -> SINGLE destination -> announce -> peer learns identity/path -> encrypted DATA packet

For this first BLE SINGLE proof, roles are still explicit:

AMY -> BLE central/client
BOB -> BLE peripheral/server

Build, Upload, And Monitor

Start BOB first so the peripheral is advertising before AMY scans.

In one console:

source /home/jlpoole/rnsenv/bin/activate
cd /usr/local/src/microreticulum/microReticulumTbeam
pio run -d exercises/302_microReticulum_ble_announce_single -e bob -t upload --upload-port /dev/ttytBOB && \
pio device monitor -d exercises/302_microReticulum_ble_announce_single -e bob

In another console:

source /home/jlpoole/rnsenv/bin/activate
cd /usr/local/src/microreticulum/microReticulumTbeam
pio run -d exercises/302_microReticulum_ble_announce_single -e amy -t upload --upload-port /dev/ttytAMY && \
pio device monitor -d exercises/302_microReticulum_ble_announce_single -e amy

The platformio.ini maps each environment to its stable USB symlink:

amy -> /dev/ttytAMY
bob -> /dev/ttytBOB
cy  -> /dev/ttytCY
dan -> /dev/ttytDAN
ed  -> /dev/ttytED

The shorter form should also work once the symlinks exist:

pio run -d exercises/302_microReticulum_ble_announce_single -e bob -t upload
pio device monitor -d exercises/302_microReticulum_ble_announce_single -e bob

Expected Output

After the BLE GATT connection is made, each node prints its local SINGLE destination hash and periodically announces it:

Local SINGLE destination: 2f6c...
TX ANNOUNCE: Amy

After the peer's announce is received, the node prints the learned destination:

RX ANNOUNCE: label=Bob hash=91a4...

Once a peer is known, it sends encrypted DATA packets to that destination:

TX SINGLE BLE: Amy -> Bob iter=0
RX SINGLE BLE: Bob -> Amy iter=0

Notes

• This exercise uses the same ESP32 BLE interface introduced in Exercise 301.
• The BLE fragmentation header matches /usr/local/src/ble-reticulum/BLE_PROTOCOL_v2.2.md: [type:1][sequence:2][total:2][payload...].
• The identity is generated on each boot. The destination hash can change after reset because the identity changes.
• App data in the announce carries the human-readable node label, such as Amy or Bob.
• This is still not a negotiated Reticulum Link; Exercise 303 should use the announced SINGLE destination as the target for a negotiated link over BLE.