The latest firmware for Ailunce HA2 has upgraded APRS Message functionality. Upgrade the radio firmware to version V1.00.06.004. 

If you want to send message from the bluetooth APP on android and ios phone. here need to upgrade the radio bluetooth version to V1.2.16. Please follow the operation below: 

How to Update RETEVIS Ailunce HA2 Firmware with Phone: Bluetooth OTA Update Guide

The firmware download link: https://www.ailunce.com/Supports/HA2/Software

Basic settings must be completed before use (messages cannot be sent without these settings)

I. Basic parameter configuration

1. Frequency and Basic Parameter Settings：

1. Adjust the Band A/B VFO or channel frequency to the local standard APRS frequency.
2. Disable the CTCSS sub-tone and DCS digital mute on the current channel (the sub-tone will intercept APRS digital data packets, resulting in the inability to receive and decode);
3.  Appropriately lower the squelch threshold to ensure that weak APRS signals can be demodulated and received normally.

2. Set your local call sign + SSID
Find APRS → Mycallsign in the menu.

- For handheld radios, enter XXXXXX-7 (-7 represents a handheld device)

APRS SMS messages cannot be sent or received without a call sign and SSID.

3. The APRS Message transmit frequency is the same as the working band frequency. 

4. Setting the forwarding Path
The APRS DIGI path is normally filled in as WIDE1-1,WIDE1-2 to ensure messages are forwarded by relays along the route, allowing long-distance recipients to receive them. 

Sending APRS MESSAGE: Step-by-Step Operation (Two Sending Methods)

 Method 1: Directly Enter the Recipient's Callsign and SSID and Create a New Message to Send to a Specific Person (point to point)

1. Enter the APRS menu on your device and select [New Message]

2. Enter the recipient's complete callsign (including SSID, e.g., BA1AAA-7), Switch the channal knob, you can select the saved contacts. Use the [MENU] key to move the cursor to the text message content box, (maximum 67 characters per message).

3. You can create some message contacts in advance on the 【Message Contacts】menu. And choose one of the message through the channel knob.

4. Press the send button to send the data packet.

5. After the recipient receives the message, the walkie-talkie will emit a "beep" sound, and the message status will be displayed as "ack" in the recipient's inbox list. This represents the automatic response confirmation mechanism of point-to-point SMS.

6. If the transmitter does not receive an ACK response from the target, the Status of the corresponding SMS message in the transmitter's outbox list will be displayed as Sent, and it will resend the message every 20 seconds when idle.

7. If three consecutive resend attempts fail (no ack is received from the target), the message will be displayed as Sent (no ack) in the sent list, and resending will stop. This usually indicates that the recipient is offline.

8. If an ACK is received from the target during the retransmission process, the Status of the corresponding SMS details page in the transmitter's outbox will change from Sent to Delivered, indicating that the SMS has been successfully delivered. Delivered SMS messages will be removed from the retransmission queue and their status will be updated. Retransmission will not increase the number of SMS messages in the transmitter's outbox.

9. Additionally, if the device is turned off during the retransmission process, it will continue to retransmit using the remaining number of attempts after being turned on again. For example, if two retransmissions have been completed when the device is turned on, it will only retransmit once more after being turned off and restarted, instead of retransmitting three times.

Quick Message

Pre-save Frequently Used Shortcut Text for quick message

The APRS quick message can store 10 fixed short phrases, each with a maximum of 60 characters:

Customizable: Arrived, Traffic Jam Ahead, Meeting in Half an Hour, Request for Assistance, All As Usual.

Eliminates the need for repetitive typing during hikes and convoy trips.   

Method 2: Reply a message to a beacon 

When you receive a APRS beacon, you can directly send a new message or quick message. Messages sent via Beacon will be saved in the receiver's inbox.

APRS Message upgrades a radio from a voice-only device to an offline collaboration tool with messaging and status reporting capabilities, and it is particularly valuable for outdoor activities and emergency scenarios.