# LED indicators

> Source: https://topodrone.com/knowledge/topodrone-slam-100/led-indicators/
> Section: TOPODRONE SLAM 100
> Updated: 2026-10-02

![LED indicators](https://topodrone.com/knowledge/i/354e8cdd2d204e7a.png)

| Indicator | Function | Meaning | Indicator color |
| --- | --- | --- | --- | --- | --- | --- |
| **Red** | **Green** | **Blue** | **Yellow** |
| GNSS | Positioning | Searching for satellites | **Blinking** |   |   |   |
| Single Point Positioning (Q1) | **Solid** |   |   |   |
| Pseudo-Range Positioning |   |   |   | **Blinking** |
| Float-Point Positioning (Q2) |   | **Blinking** |   |   |
| Absolute Point Positioning (Q5) |   | **Solid** |   |   |
| Base station mode |   |   | **Solid** |   |
| Board configured successfully | **Blinking slowly** |   |   |   |
| Bluetooth | Bluetooth | Preparing | **Blinking** |   |   |   |
| Initializing, disconnected | **Solid** |   |   |   |
| Connected |   | **Solid** |   |   |
| 4G | Data transfer | Data not ready | **Blinking** |   |   |   |
| SIM card read successfully |   | **Blinking** |   |   |
| 4G connected |   | **Solid** |   |   |
| Differential data |   | **Blinking fast** |   |   |
| Power | Power | No SD card | **Blinking** |   |   |   |
| USB connected | **Solid** |   |   |   |
| Normal operation |   | **Blinking** |   |   |
| SD card write error |   |   | **Solid** |   |