MagicBit

ESP32-based educational board with sensors, display, and expansion - great for IoT learning and STEM kits.

Micro-USB
MagicBit board
ESP32
MCU
240MHz
clock
4MB
flash
520KB
SRAM
26· 16 ADC
GPIO
BLE 4.2+ WiFi
radio
On this page

MagicBit Pinout

26 pins
PinGPIOLabelsStatusCapabilitiesNotes
10A11T1strappingadc · touch
21TXPWMuartuart
32A12T2PWMstrappingadc · touch
43RXPWMuartuart
54A10T0PWMstrappingadc · touch
65SSPWMstrappingspi
712A15T5PWMstrappingadc · touch
813A14T4PWMstrappingadc · touch
914A16T6PWMstrappingadc · touch
1015A13T3PWMstrappingadc · touch
1116GREEN_LEDMOTOR2APWMstrapping-
1217BLUE_LEDMOTOR2BPWMstrapping-
1318SCKYELLOW_LEDMOTOR1BPWMsafespi
1419MISOPWMsafespi
1521SDAPWMsafei2c
1622SCLPWMsafei2c
1723MOSIPWMsafespi
1825A18DAC1BUZZERPWMsafeadc · dac
1926A19DAC2PWMsafeadc · dac
2027A17T7RED_LEDMOTOR1APWMsafeadc · touch
2132A4T9PWMsafeadc · touch
2233A5T8PWMsafeadc · touch
2334A6RIGHT_BUTTONstrappingadc
2435A7LEFT_BUTTONstrappingadc
2536A0LDRstrappingadc
2639A3POTstrappingadc
26 GPIOs broken out 10 free · 16 need care · 0 to avoid

Start with these

10 pins with no boot or system involvement
SCKGPIO18MISOGPIO19SDAGPIO21SCLGPIO22MOSIGPIO23A18GPIO25A19GPIO26A17GPIO27A4GPIO32A5GPIO33

Freely assignable - no strapping, flash, USB or JTAG duties. Ideal first picks for buttons, sensors and LEDs.

Fine - with a little care

16 pins · 14 things to know
A11GPIO0 Bootstrapping pin (enter bootloader when low); internal pull-up. Strapping

Must be HIGH during boot for normal startup; if held LOW on reset, forces flash programming mode.

TXGPIO1 Default UART0 TX pin for USB-serial programming and console. UART

Connected to on-board USB-UART for uploading and logs; drives serial output at boot, so using as GPIO can disrupt programming or console.

A12GPIO2 Bootstrapping pin (must be low or floating at reset); internal pull-down. Strapping

If driven HIGH on reset (while IO0 is LOW), selects an unsupported SDIO boot mode, causing boot failure.

RXGPIO3 Default UART0 RX pin for USB-serial programming (console input). UART

Used for receiving data from USB-UART (programming); also pulled HIGH at boot for console communication, so using as GPIO can disrupt uploads.

A10GPIO4 Bootstrapping pin; internal pull-down; also HSPIHD (flash data line) on modules with internal flash. Strapping

Sampled at reset for boot config; should not be driven at boot (affects boot mode timing).

SSGPIO5 Bootstrapping pin; internal pull-up; VSPI CS0 (default SPI chip-select); acts as FSPIWP (flash write-protect) on internal-flash variants. Strapping

Must be HIGH during boot; if pulled LOW at reset, alters SDIO slave timing and may prevent normal boot.

A15GPIO12 Bootstrapping pin; JTAG TDI; sets flash voltage (VDD_SDIO); also HSPIQ (flash data line). Strapping

Keep LOW during boot (internal PD); pulling HIGH at reset selects 1.8V flash mode, causing flash brownout if 3.3V flash is used.

A14GPIO13 JTAG clock pin (TCK); also ADC2 channel 4 / Touch4 input. JTAG

Used for JTAG debugging (TCK); avoid using as GPIO if JTAG is needed.

A16GPIO14 JTAG mode select pin (TMS); also HSPI CLK and PWM-capable GPIO. JTAG

Used for JTAG debugging (TMS); driving it as GPIO may interfere with JTAG or produce spurious signals at boot.

A13GPIO15 Bootstrapping pin; JTAG TDO; controls UART0 boot log output; also HSPICS0 (secondary SPI CS). Strapping

Keep HIGH during boot (internal PU); if LOW on reset, bootloader log is silenced and boot mode may change.

GREEN_LEDGPIO16BLUE_LEDGPIO17 PSRAM chip select and clock on WROVER-class modules; in-package flash lines on ESP32-U4WDH. Both also carry UART2 PSRAM

Wired to the memory die on PSRAM-equipped modules (WROVER, PICO-V3-02) and on in-package-memory chip variants (U4WDH, D0WDRH2-V3); an ordinary GPIO on a plain WROOM-32.

  • GREEN_LEDPSRAM CS# on WROVER-class modules and on ESP32-D0WDRH2-V3; in-package flash CS# on ESP32-U4WDH. Also UART2 RX.
  • BLUE_LEDPSRAM clock on WROVER-class modules; in-package flash IO1/DO on ESP32-U4WDH. Also UART2 TX.
A6GPIO34 Input-only GPIO (no output driver); ADC1 channel 6. Other

Cannot be used as output (no drive capability); only suitable for analog/digital input.

A7GPIO35A3GPIO39 Input-only GPIOs with ADC1 channels - no output driver Other

Cannot be used as output; only suitable for input.

  • A7Input-only GPIO (no output driver); ADC1 channel 7.
  • A3Input-only GPIO (no output); ADC1 channel 3, Hall sensor VN.
A0GPIO36 Input-only GPIO (no output); ADC1 channel 0, Hall sensor VP. Other

Cannot be used as output; only suitable for input (e.g., analog read).

These are recommendations, not hard rules - with the right pull-ups, timing and boot-state awareness most pins can be made to work. When in doubt, start green.

The MagicBit pinout brings out 26 GPIO pins - every one of them usable in your project.

For peripherals, I²C is mapped to SDA on GPIO21 and SCL on GPIO22; the SPI bus (MOSI, MISO, SCK, SS) is broken out in full; TX/RX on GPIO1 and GPIO3 cover serial logging and flashing.

On the analog side there are 16 ADC-capable pins for sensors and battery monitoring, 10 capacitive-touch inputs and 2 true DAC outputs.

If you want zero surprises, SCK, MISO, SDA, SCL and 6 more are free of any such role - the safest first picks. 16 of the exposed pins carry boot-time or system duties on the ESP32 (A11, TX, A12 and 13 more).

Getting started

flash your first firmware in ~2 minutes
Tool:
1
Connect over USB
Uses a CH340 bridge - install the CH340 driver if no port appears. Not detected? Hold BOOT while plugging in.
2
Match & flash
Set the Tools options shown, then click Upload.
3
Verify it runs
GPIO18 toggles - wire an LED and resistor to it, or change the pin to your board's own LED.
Set these in Tools · leave everything else at default
Arduino IDE 2.x - Tools Copy
Board: "ESP32 Dev Module"
Flash Size: "4MB (32Mb)"
Flash Mode: "DIO"
Partition Scheme: "Default 4MB with spiffs (1.2MB APP/1.5MB SPIFFS)" (default)
Upload Speed: "921600"
▸ every other Tools option - leave at default
Board: ESP32 Dev Module
Flash Size: 4MB (32Mb)
Flash Mode: DIO
Partition Scheme: Default 4MB with spiffs (1.2MB APP/1.5MB SPIFFS)
Upload Speed: 921600
Find it: Tools ▸ Board ▸ ESP32 Arduino ▸ ESP32 Dev Module
blink.ino Copy
// toggle GPIO18 - wire an LED and resistor to it
void setup() {
  pinMode(18, OUTPUT);
}
void loop() {
  digitalWrite(18, HIGH); delay(500);
  digitalWrite(18, LOW);  delay(500);
}
board to selectesp32dev⧉ copy
platformio.ini Copy
[env:magicbit]
platform = espressif32
board = esp32dev
framework = arduino
monitor_speed = 115200
upload_speed = 921600
Find it: PlatformIO Home ▸ Boards, search esp32dev - or type it after board =.
board to selectesp32dev⧉ copy
device.yaml Copy
esp32:
  board: esp32dev
  variant: esp32
  framework:
    type: esp-idf

# blink - GPIO18
output:
  - platform: gpio
    pin: 18
    id: led_out
light:
  - platform: binary
    name: "LED"
    output: led_out
Find it: search ESPHome's board list for esp32dev (same ids as PlatformIO).
esptool doesn't pick board settings - a prebuilt .bin already has them baked in. This is just the raw flash command.
terminal Copy
esptool.py --chip esp32 --port /dev/ttyACM0 \
  --baud 921600 write_flash 0x1000 firmware.bin
--port = your /dev/tty* (macOS/Linux) or COMx (Windows).
Build details: sketch space 1310720 B · data 327680 B · DIO

Specifications

ESP32 · vs other ESP32 chips →
Compute
MCU
ESP32
Clock
240 MHz
SRAM · Flash
520 KB · 4MB
Radio
Wi-Fi
802.11 b/g/n
Bluetooth
4.2 LE
Antenna
PCB
I/O
GPIO · ADC
26 · 16
UART · I²C · SPI
3 · 2 · 2
PWM
16 channels
Power
USB
Micro-USB
Serial
CH340
Boot address
0x1000
Electrical
Input
5V USB · 3.7V LiPo
Consumption
-
Regulator
-
Display
Screen
OLED · 0.96" · 128x64
Driver
SSD1306
Touch
No
Flashing
Upload · OTA
esptool_py · esp_ota
Flash · Boot mode
DIO · DIO
Sketch · Data
1.25 MB · 320 KB
The MagicBit uses esptool_py for firmware uploads, esp_ota for over-the-air (OTA) updates. Flash mode is DIO with DIO boot mode. The maximum sketch size is 1.25 MB with 320 KB available for data.

About this board

At its core is the ESP32 - a dual-core Xtensa with both Bluetooth Classic and BLE.

Onboard you'll find an OLED 0.96" 128x64 display, a buzzer, an ambient-light sensor, battery charging, status LEDs (Red, Yellow, Green, Blue) and Left/Right buttons.

Resources

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