# Xiaomi LYWSD03MMC ATC, PVVX or BTHome v2(*) firmware
| Model Id | LYWSD03MMC_ATC/PVVX/BTHOME (opens new window) |
|---|---|
| Brand | Xiaomi |
| Model | Compact Temperature sensor |
| Short Description | Temperature and humidity sensor compact and cost effective with ATC or PVVX firmware |
| Communication | BLE broadcast |
| Frequency | 2.4Ghz |
| Power Source | CR2032 |
| Exchanged Data | temperature, humidity, battery, voltage, packet, power, open (depending on which LYWSD03MMC firmware is installed) |
| Encrypted | Yes/No - Optional |
| Image |  |
(*) For the BTHome v2 format to be recognised when using the PVVX TelinkMiFlasher the device name must start with the default prefix of "ATC".