Worked on the meshtastic/firmware repository to implement cross-device touch-to-backlight support for the T-Echo family of devices. Using C++ and embedded systems expertise, generalized the e-ink backlight gating mechanism by replacing device-specific logic with a device-agnostic approach based on the PIN_EINK_EN signal. This change enabled the touch-to-backlight feature on all devices equipped with an e-ink backlight pin, achieving feature parity between T-Echo and T-Echo Plus models. The solution addressed a previously reported limitation, resolved Issue #7630, and reduced ongoing support needs by ensuring consistent firmware behavior across supported hardware. Focus areas included firmware development and hardware abstraction.