An ESP32-Based Packet Monitor

Alasdair Allan
2 min readFeb 21, 2018


The Espressif Systems ESP8266 and the ESP32 modules have become my favorite “go to” boards for hacking out projects, and I’m not alone.

The original Packet Monitor board put together by Stefan Kremser was based around the ESP8266 and allowed you to monitor the wireless space around you. However with the arrival of the ESP32, it was due for an upgrade.

The new PacketMonitor32. (📷: Stefan Kremser)

Built around the ESP32-Wrover module, which has 4MB Flash and 4MB PSRAM, with the new higher specification hardware the PacketMonitor32 board comes with SD card support which can be used to save the captured traffic into a PCAP file.

The PacketMonitor32 also has a 1.3-inch OLED, and a battery charging circuit that includes both over-charging and over-discharging protection, enabling the board to run entirely from a LiPo battery.

The board is available in two different versions, one with an external antenna, and one with a PCB antenna, and comes pre-flashed with the open source packet monitoring software.

The PacketMonitor32 with PCB antenna (left) and IPEX antenna (right). (📷: Travis Lin)

The PacketMonitor32 board is now on Tindie, or on AliExpress, with a price tag of $19 plus shipping. The version with the external antenna costs an additional $1 for a 2dBi antenna, or an additional $2 for a 8dBi antenna. Although if you want to log packets, you’ll also need to pick up an SD card.