wiring_m2560.md

Heltec E-ink Modules

Wiring: ATmega2560

❌ Connecting directly to display will cause damage.

The ATmega2560 operates at 5V. The display operates at 3.3V.
To connect safely, a "level-shifter" is needed.

Display	Arduino
VCC	3.3V
GND	GND
D/C	D2 *
SDI	D51
CS	D4 *
CLK	D52
BUSY	D5 *

* Can be changed. Set in constructor.

Suggested wiring, with level shifting:

Note: The BUSY pin does not require level-shifting, as the ATmega2560 only reads this pin, never outputting 5V.

(Optional) Suggested additional wiring, for power saving

void setup() {
    // Pin 53, PNP transistor
    display.useCustomPowerSwitch(53, PNP);

    //Later, when required:
    display.customPowerOff();
    display.customPowerOn();
}

(Optional) Additional wiring: MicroSD card module

⚠ Connecting directly to MicroSD module may cause damage.

These Arduinos use 5V. MicroSD operates at 3.3V.
Your MicroSD module may have an inbuilt level shifter. Many do not.

This diagram shows possible wiring for MicroSD modules which do not have an inbuilt level-shifter. Your may be able to connect directly.

❗ Take care when combining this wiring and useCustomPowerSwitch().
NPN or ACTIVE_LOW configurations will damage the SD card.

For greater protection, consider a bidirectional level shifter.