Fishino Architecture & Theory
Fishino IoT boards combine standard AVR microcontrollers (ATmega328P on UNO/Guppy, ATmega2560 on MEGA) with an onboard ESP8266 WiFi chip, a microSD card slot, and a dedicated RTC (Real-Time Clock) module to create all-in-one IoT prototyping platforms. Because these components are integrated directly on-board, they share unified SPI and I2C buses, eliminating the need for complex, messy stacking shields and manual wire jumpers.
Tip: Standard Fishino boards run on 5V logic for AVR pins, but the onboard ESP8266 WiFi module uses 3.3V. The boards include level shifters, but any external 3.3V sensors wired to the GPIO headers still require appropriate level shifting.
About This Reference Guide
Your direct lookup path for Fishino UNO, MEGA, and compact Guppy IoT boards.
This reference index consolidates pin configurations, expansion header maps, and line assignments for the complete Fishino ecosystem.
Finding accurate pin layouts is essential for firmware developers, IoT engineers, and electronics makers. Precise pin alignments prevent hardware conflicts, communication dropouts, and permanent board damage from short-circuits.
Always verify operating voltages (5V vs 3.3V) before constructing custom connections. Correct connection paths preserve performance and safety.
AVR ControllersATmega328P and ATmega2560 compatible hardware bases.
Wireless FocusOnboard ESP8266 modules for complete WiFi integration.
Storage OptionsIntegrated microSD card slots for data-logging applications.
Circuit ProtectionOnboard level shifting to protect the 3.3V WiFi processor.
Frequently Asked Questions
1. What makes Fishino boards different from standard Arduinos?
Fishino boards integrate essential IoT components—including a WiFi module (ESP8266), a microSD card reader, and a real-time clock (RTC)—directly onto the main board, eliminating the need for stacking shields.
2. How does the SPI bus work with multiple onboard devices?
The AVR microcontroller uses Chip Select (CS) pins to choose which device to communicate with. Pin 10 is reserved for the SD card, pin 4 for the Ethernet (on supported modules), and pin 11 for the WiFi module.
3. Can I use standard Arduino shields on Fishino boards?
Yes. Fishino UNO and MEGA share the same pin layouts and form factors as standard Arduino UNO and MEGA boards, making them fully compatible with standard shields.
4. What is the logic level of the GPIO pins?
All standard GPIO pins run on 5V logic. Onboard level shifters protect the 3.3V ESP8266 chip and microSD slot, but external 3.3V sensors still require level translation.
5. What is the Fishino Guppy?
The Fishino Guppy is a compact, breadboard-friendly version of the Fishino UNO. It retains the ATmega328P controller, microSD slot, and ESP8266 WiFi, but packages them into a small Nano-sized form factor.
6. How do I update the onboard ESP8266 firmware?
Fishino boards include a dedicated serial pass-through mode. By uploading a standard serial-bridge sketch to the main AVR processor, you can flash firmware updates directly to the ESP8266 via USB.