Everything about the E1, E2, and E3 extension boards:
All extension boards have common attributes, to make them interchangeable, and easy-to use. The unused Raspberry Pi pins are connected to a prototyping area for easier connectivity.
/Ratherboard is compatible with the RPi. Raspberry Pi is a trademark of the Raspberry Pi Foundation/
The huge prototyping area of the extension boards offers place for a vast number of through-hole components making the prototyping possibilities endless. In the middle of the prototyping area a small breakout area is placed which features footprints for parts with a small-outline case, extending the range of selectable components even further.
The protected nominal 12 Volt supply connected to the input of the Ratherboard is fed to the expansion board via a 10-pin header connector making it possible to use 12 Volt sensors or drive outputs directly from the expansion board.
The E1 extension board offers a general IO solution for 12 pins of the Raspberry Pi. On the dark side there are pre-soldered transient suppressor diodes and series resistors, while the red side has numerous SMD footprints that can be populated with pullup or pulldown resistors, RC filters or resistor dividing networks as the user requires.
The E2 expansion board contains 5 optocoupled outputs and another 5 optocoupled inputs built in with all the required resistors on the dark side of the card. The optocoupled ports when used correctly, protect the sensitive circuit inside the device from extreme conditions like high voltages or signals with a floating reference. Of course, general design guidelines should always be followed.
The E3 extension board contains an “LTC1687” 8 channel analog to digital converter with 16 bit resolution, serial communication and internal voltage-reference. All ADC channels have two input amplifier stages which can amplify or attenuate the input signal to the desired level to ensure maximum accuracy. The user-selectable resistors are on the red side of the PCB for convenience. Not only the amplifier gain for each channel but also the supply voltage of the amplifiers can be adjusted.
Optional resistors on the input make the board compatible with sensors using a 4 to 20 mA current loop output, frequently used in industrial applications.
On the dark side two additional “MCP4725” 12-bit digital to analog converters are placed to generate analog outputs for example to control other devices. Again, the output amplifier supply voltage is selectable from 3.3 Volt, 5 Volt and 12 Volt.
All-in-all the E3 expansion board is a complex, highly customisable, yet straightforward analog to digital extension to the Ratherboard.
12 other extension board types will arrive when reaching the related stretch goals of our Indiegogo campaign!