Ramps are short for RepRap Arduino Mega Pololu shield, it is mainly designed for the purpose of using the pololu stepper driven board (similar to 4988 driven board). Ramps can only work when connected to its motherboard Mega 2560 and 4988/DRV8825. Owning to its stability in operation and great compatibility with most 3Dprinter (all RepRap-model such as purse i2 and i3). The combination of Ramps1.4+MEGA2560+A4988/DRV8825 is becoming a mainstream of DIY 3D printer control board.RAMPS Shield 3D Printer
The IOIO-OTG (pronounced “yo-yo-O-T-G”; the OTG stands for On-The-Go) is a development board specially designed to allow developers to add advanced hardware I/O capabilities to their Android or PC application. It features a PIC microcontroller, which acts as a bridge that connects an app to your PC or Android device to low-level peripherals like GPIO, PWM, ADC, I2C, SPI, and UART. An app-level library helps you write control code for these low-level peripherals in the same way you’d write any other Java app!