espfetch

Neofetch-style system info + Python-style logger for ESP32/ESP8266.

What You Get

     ||||||||         espfetch@esp32-D03FE0
  .--+------+--.      ----------------------------
  |            |      Chip      ESP32-D0WD-V3 rev300
  |   ESP-32   |      Cores     2 @ 240 MHz
  |            |      SDK       v5.5.2
  '--+------+--'      Temp      53.3 C
     ||||||||
                      Uptime    0d 1h 23m 45s
                      Reset     Power-on
                      Tasks     13

                      Heap      172 / 323 KB (53% free)
                      MinFree   165 KB
                      MaxBlock  107 KB
                      Flash     4096 KB QIO 80 MHz
                      Sketch    1025 / 4097 KB

                      Mode      STA
                      WiFi      [███░] Hamza -64 dBm ch11
                      IP        192.168.1.101
                      Gateway   192.168.1.1
                      DNS       192.168.1.1
                      MAC       C0:49:EF:D0:3F:E0
                      Hostname  esp32-D03FE0
                      TxPower   19.5 dBm

                      Tunnel    self-hosted
                      URL       https://...

Features

• Full system diagnostics — chip, cores, temp, heap, flash, SPIFFS, LittleFS, PSRAM, WiFi signal bars
• Neofetch-inspired — IC-chip ASCII art with side-by-side info
• ESPLogger — Python/FastAPI-style logging with levels (logger.info(), logger.error(), logger.request())
• Thread-safe — FreeRTOS mutex on ESP32, no-op on ESP8266
• Auto-detects tunnel — shows esp32-tunnel status if linked
• ESP32 + ESP8266 — works on all Espressif boards

Installation

Arduino Library Manager

1. Sketch → Include Library → Manage Libraries
2. Search "espfetch"
3. Install

Manual

Download ZIP → Sketch → Include Library → Add .ZIP Library

Quick Start

#include <espfetch.h>
#include <WiFi.h>

void setup() {
  rtosSerial.begin(115200);
  WiFi.begin("SSID", "PASS");
  while (WiFi.status() != WL_CONNECTED) delay(500);

  logger.info("WiFi connected: %s", WiFi.localIP().toString().c_str());
}

void loop() {
  if (Serial.available()) {
    String cmd = Serial.readStringUntil('\n');
    cmd.trim();
    if (espfetch.check(cmd)) return;
  }
}

Type /espfetch in Serial Monitor → see system info.

ESPLogger

Python-style logging with 5 levels:

logger.debug("x = %d", x);          // DEBUG:    x = 42
logger.info("Server started");       // INFO:     Server started
logger.warning("Low memory: %d", h); // WARNING:  Low memory: 1024
logger.error("Connection failed");   // ERROR:    Connection failed
logger.critical("System halt");      // CRITICAL: System halt

logger.request("1.2.3.4", "GET", "/", 200);
// INFO:     1.2.3.4 - "GET /" 200

logger.setLevel(ESPLogger::LVL_WARNING);  // hide DEBUG + INFO

Thread-safe on ESP32 via FreeRTOS mutex. Default level: LVL_INFO.

API

espfetch

Function	Description
espfetch.check(cmd)	Returns true if cmd was handled (/espfetch, /fetch, /info)
espfetch.print()	Print system info (use print(true) for full details)
espfetch.printJSON()	Print system info as JSON

ESPLogger

Function	Description
logger.debug(fmt, ...)	Debug level message
logger.info(fmt, ...)	Info level message
logger.warning(fmt, ...)	Warning level message
logger.error(fmt, ...)	Error level message
logger.critical(fmt, ...)	Critical level message
logger.request(ip, method, path, status)	FastAPI-style request log
logger.setLevel(level)	Set minimum level (LVL_DEBUG .. LVL_CRITICAL)

Displayed Info

Section	Fields
Chip	Model, revision, cores, frequency, SDK, internal temperature
Runtime	Uptime, reset reason, FreeRTOS task count
Memory	Heap (free/total/%), min free, max block, flash, sketch, PSRAM, SPIFFS, LittleFS
Network	WiFi signal bars, SSID, RSSI, channel, IP, gateway, DNS, MAC, hostname, TX power
Tunnel	Provider, status, URL (auto-detected from esp32-tunnel)

JSON Output

espfetch json (or espfetch.printJSON()) outputs a single JSON object:

Field	Type	Platform	Description
chip	string	both	Chip model and revision
cores	int	both	Number of CPU cores
freq_mhz	int	both	CPU frequency in MHz
sdk	string	both	SDK version
temp_c	float	ESP32	Internal temperature (°C)
chip_id	string	ESP32	eFuse MAC as hex
fw_md5	string	ESP32	Sketch MD5 hash
uptime_s	int	both	Uptime in seconds
reset	string	both	Last reset reason
boot_count	int	ESP32	Total boot count (persisted in NVS)
tasks	int	ESP32	FreeRTOS task count
heap_free	int	both	Free heap bytes
heap_total	int	ESP32	Total heap bytes
heap_min_free	int	ESP32	Minimum free heap ever
heap_max_block	int	ESP32	Largest allocatable block
flash_kb	int	both	Flash size in KB
sketch_kb	int	both	Sketch size in KB
sketch_total_kb	int	both	Total sketch space in KB
psram_free	int	ESP32*	Free PSRAM (*if present)
psram_total	int	ESP32*	Total PSRAM (*if present)
wifi_mode	string	both	STA / AP / AP+STA / OFF
ssid	string	both*	Connected SSID (*if connected)
rssi	int	both*	Signal strength in dBm
channel	int	both*	WiFi channel
ip	string	both*	Local IP address
mac	string	both	MAC address

Integration with esp32-tunnel

espfetch auto-detects esp32-tunnel via C++ weak symbols. If esp32-tunnel is linked, tunnel info (provider, URL, last IP) appears automatically — no configuration needed.

To integrate your own library the same way, define these functions:

String tunnelURL();
const char* tunnelProviderName();
bool tunnelReady();
String tunnelLastIP();

espfetch declares them as __attribute__((weak)) stubs that return empty/false by default. Your strong definitions override them at link time.

Companion Libraries

• esp32-tunnel — expose your ESP32 to the internet
• esp-rtosSerial — thread-safe Serial reads for FreeRTOS

License

MIT

Author

Hamza Yesilmen — @HamzaYslmn