Features:

1. 4inch IPS screen, 480×800 hardware resolution.
2. Resistive touch control.
3. Compatible and Direct-connect with any revision of Raspberry Pi (except the Pi 1 Model B or Pi Zero, which requires an HDMI cable).
4. Drivers provided (works with your own Raspbian/Ubuntu/Kali/Retropie).
5. Also works as a computer monitor, in this case, the touch panel is unavailable and an HDMI cable is required.
6. HDMI interface for displaying, no I/Os required (however, the touch panel still needs I/Os).
7. 3.5mm audio jack, supports HDMI audio output.
8. The backlight can be turned off to lower power consumption.

Features:

1. Onboard touch controller, smoother touch experience than solutions that directly use AD pins for touching.
2. SPI interface requires a few pins.
3. Programmable backlight control, power saving.
4. Comes with development resources and a manual (examples for STM32/AVR/PIC).

Note :

1. The Nema17 0.15N-m Stepper motor dimensions and weight may have a ±2% error.
2. Resonances can occur because of improper mounting.
3. Not easy to operate at extremely high speeds.

Features :

1. The input pulse decides the rotation angle of the motor.
2. High accuracy of around 3 to 5% a step.
3. It provides good starting, stopping, and reversing.
4. Control of this motor is less costly because of the exclusion of complex control circuitry.
5. The speed is proportional to the frequency of the input pulses.

Features:

1. Guaranteed leakproof operation in any position except inverted
2. The expected life span of two to three years in float service applications
3. Operation in a broad range of ambient temperatures
4. Recovery capabilities even after deep discharges
5. Compact, quick and simple to install, require low maintenance