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Introducing ISaAC an new add-on adapter for Raspberry PI

03 Aug Posted by in New Educational Capability | Comments Off
Introducing ISaAC an new add-on adapter for Raspberry PI


Welcome to ISaAC, a small form factor programmable 32-bit Experimenter, featured on the front cover of August 2014 Nuts and Volts. All the information you need to install and operate ISaAC ( ISaAC Python Libraries, ISaAC technical manual)  is on this web site

ISaAC is available for purchase from Nuts and Volts store web site.

The ISaAC or, Ideal System and Application Circuit, is used as an add-on board for the Raspberry Pi (Raspi). ISaAC is designed for rapid application development and ease of use. No special programming is required, as the ISaAC comes pre-programmed for the Raspi with an Application Programming Interface (API). The API provides for Raspi power control and external system power +5VDC on/off, an on board EEPROM for read/write of both data, a 100 year Real Time clock calendar (RTCC) with multiple programmable alarm capabilities, 4 analog digital converter (ADC) conversion inputs, a programmable digital analog out (DAC) signal output, 13 digital I/O, and dual pulse width modulation (PWM) outputs for servos and sound.


ISaAC follows an Arduino Interface. All pins are labeled on the silkscreen of the ISaAC board.

  • (9) Digital I/O programmable

–      DO,D1,D2,D8,D9,D10,D11 or 0,1,2,8,9,10.11,12,13

–      D9 and D10 can be configured as PWM

–      API uses pin numbers 00, 01,02,03,04,05,06,07,08,09,10,11,12,13

  • (4) Analog In ( 10 bit resolution) or Digital I/O programmable

–      A0,A1,A2,A3

–      API uses pin numbers 14,15,16,17

  • (1) Analog Out (DAC) ( 10 bit resolution)

–      VOUT (buffered)-recommended, DACOUT (un-buffered)

  • An accessible I2C Bus: pins A4 (data) A5 (clock)

–      Bus contains EEPROM and DAC

Other features:

  • Raspi GPIO pin breakout
  • Micro USB for +5V power
  • Raspi Power Select Jumper for switchable control of power to Raspi
  • Separate external +5V power switch for external circuits.
  • An ICSP ( In Circuit Serial Programmer) interface

–      Custom flash programming and debug

ISaAC uses the Raspi GPIO serial port (19200 8N1) for API communications. API commands are ASCII upper case characters and are echoed back for easy debugging. Command verification from ISaAC is simply ‘A’ (acknowledge) or ‘N’ (not acknowledge). There are 19 unique API commands.

API Commands Function
? query state of digital input pin
A set pin to analog input/read
CR Read RTCC clock
CS Set RTCC clock
D output to DAC
ER single EEPROM read
EW single EEPROM write
H set   output pin high
I Configure pin for digital input
L set output pin low
M Help Menu
O Configure pin for digital output
P set pin to PWM output
Q build script
T Set alarm
U PI power cycle on alarm
X execute script
Z Z – precision pulse