====== Test Mode / RF Commands ======

This page documents AT commands used for test mode, RF transmission, and modulation configuration in HaLow firmware 2.x modules.

===== AT+TEST_START – Enter or Exit Test Mode =====

**Query:**  
  <code>AT+TEST_START=?</code>

**Set:**  
  <code>AT+TEST_START=1</code>  *(start test mode)*  
  <code>AT+TEST_START=0</code>  *(stop test mode)*

**Response:**  
  <code>1:+TEST_START:test mode started
0:+TEST_START:test mode stopped
OK</code>

**Notes:**  
  * Test mode allows RF Tx/Rx tests  
  * Settings are not saved after power-off  

===== AT+LO_FREQ – Set Frequency in Test Mode =====

**Query:**  
  <code>AT+LO_FREQ=?</code>

**Set Frequency:**  
  <code>AT+LO_FREQ=924000</code>  *(KHz, 924 MHz)*

**Response:**  
  <code>LO freq = 924000 KHz</code>

**Notes:**  
  * Freq unit = KHz  
  * Not saved after power-off  

===== AT+TX_START – Enter or Exit Tx Mode =====

**Query:**  
  <code>AT+TX_START=?</code>

**Set Tx Mode:**  
  <code>AT+TX_START=1</code>  *(start Tx)*  
  <code>AT+TX_START=0</code>  *(stop Tx)*

**Response:**  
  <code>1:+TX_START:tx test started
0:+TX_START:tx test stopped
OK</code>

**Notes:**  
  * Tx mode is selected while in test mode  
  * Rx mode remains default  
  * Not saved after power-off  

===== AT+TX_MCS – Set Tx MCS =====

**Query:**  
  <code>AT+TX_MCS=?</code>

**Set MCS:**  
  <code>AT+TX_MCS=2</code>

**Response:**  
  <code>+TX_MCS:255
OK</code>

**Notes:**  
  * 255 = automatic MCS adjustment  
  * Range: 0~7, or 10 in 1M mode  
  * Fixed values override auto adjustment  
  * Not saved after power-off  

===== Notes =====

* Test mode commands are useful for RF performance evaluation and calibration.  
* Always ensure the module is in test mode before using frequency or Tx commands.  
* Settings in test mode do not persist after power-off.