Open Data Acquisition System

Block Diagram

The Open Data Acquisition System consists of a Data Acquisition Processor (DAP) and up to 8 I/O cards.

The block diagram is:

Features

The Open Data Acquisition System features a powerful combination of Open Hardware and Open Software to access low level hardware interfaces from a Host Computer.

Open Hardware

• Support for standard microprocessors such as Arduino, Raspberry Pi, BeagleBone Black
  • STM32F103 "Blue Pill" CPU
  • STMF4XX "Black Pill" CPU"
  • Raspberry Pi Pico CPU
  • Arduino UNO CPU
  • ATMEGA32U4 Arduino Leonardo compatible Processor
• Industry-Standard USB Host Interface
• Industry-Standard I2C Bus Interface to cards
• ODAS card design specification
  • ODAS form factor is an open form factor which provides an inexpensive and small card size (approx 4" square)
  • Mix and match card types

Open Software

• USB Interface runs industry standard Firmata
• Processor card runs Arduino Leonardo compatible software
• Arduino "Wire" Standard I2C bit driver
• Community supported Python, C++, Ruby, LabView, VxWorks drivers

Personality EEPROM

• Based on Raspberry Pi Hat Spec

struct eep_vals
{
  char signature[4]; // "ODAS" in ASCII
  byte fmt_version;  // EEPROM data format version (0x00 reserved, 0x01 = first version)
  byte rsvd;         // set to 0
  short numatoms;    // set to 2
  long eeplen;       // set to 96 dec
  char uuid[16];     // "0000000000000000" in ASCII
  short pid;         // See PID table
  char vslen;        // set to 32 dec
  char pslen;        // set to 32 dec
  char vstr[32];     // Vendor Null terminated String
  char pstr[32];     // Product Null terminated String
};

Product ID Table

Signature=ODAS
Vendor=land.boards.com

ProductID (in hex)	Product (string)
1	DIGIO16-I2C
2	DIGIO128
3	OptoIn8-I2C
4	OptoOut8-I2C
5	DIGIO32-I2C
6	PROTO16-I2C
7	
8	
9	

Drivers

Arduino

• Adafruit MCP23008 driver
• Adafruit MCP23017 driver

Host Software - Firmata

Firmata is a generic protocol for communicating with microcontrollers from software on a host computer. It is intended to work with any host computer software package. Right now there is a matching object in a number of languages. It is easy to add objects for other software to use this protocol. Basically, this firmware establishes a protocol for talking to the Arduino from the host software. The aim is to allow people to completely control the Arduino from software on the host computer.

Firmata has an attractive Test Program User Interface which could be easily extended

Raspberry Pi

• Enabling The I2C Interface On The Raspberry Pi
• MCP230xx GPIO Expander on the Raspberry Pi
• Adafruit library code for Raspberry Pi

lsmod dump with DIGIO-128 card attached

pi@raspi3 ~ $ lsmod | grep i2c_
i2c_dev                 5557  0
i2c_bcm2708             3997  0
pi@raspi3 ~ $ sudo i2cdetect -y 1
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: 20 21 22 23 24 25 26 27 -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: 50 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --

Raspberry Pi Performance with DIGIO-128 card attached

• sudo python Adafruit_MCP230xx.py
• Clock runs at 100 KHz

• Overall timing - 1 cycle

• Overall timing - 2 cycle (Read-modify-write)

ESP32 MicroPython Drivers

• MicroPython Drivers and Libraries for ODAS cards

PyBoard MicroPython Drivers

• MicroPython Drivers and Libraries for ODAS cards

Cards

Opto-Isolated Cards

Optically Isolated cards are necessary to connect together different electrical system without concerns for ground loops, voltage dropes or electrical noise. ODAS offers two optically isolated cards; one for input and one for output.

• OptoIn8-I2C - 8-Channel Optically Isolated Input Card
• OptoOut8-I2C - 8-Channel Optically Isolated Output Card

Digital I/O Cards

Card	Function	Interface type
CARRIER95TO49MM	Adapt ODAS 49mm to 95mm cards	N/A
DCE	RS-232/TTL Converter	TTL
DTE	RS-232/TTL Converter	TTL
DIGIO-128	128-bit Digital I/O Card	I2C
DIGIO32-I2C	32-bit Digital I/O Card	I2C
DigIO16-I2C	16-bit Digital I/O Card	I2C
Front Panel For 8 Bit Computers	Front Panel for 8-bit Microprocessors with I2C interfaces (SMT)	I2C
Front Panel for 8 Bit Computers V2	Front Panel for 8-bit Microprocessors with I2C interfaces (Thru-hole)	I2C
I2CIO16-DB25	16-bit I2C I/O based on the MCP23017	I2C
I2CIO-8X	8-bit I2C I/O based on the MCP23008	I2C
I2CIO-8	8-bit I2C I/O based on the MCP23008	I2C
I2C-TEMP	I2C Temperature Sensor	I2C
I2C-RPT	4-Channel I2C Multiplexer/Repeater	I2C
I2C-RPT-08	8-channel I2C Multiplexer/Repeater	I2C
ODAS-PSOC5	Programmable System On a Chip	I2C, SPI, TTL
ODAS-RELAY-16	16 Channel Relay Card	I2C
PROTO16-I2C	16-bit I/O with prototyping area	I2C
PS2X49	PS/2 keyboard/mouse interface	TTL
SWLEDX8	8 Switches and 8 LEDs	I2C
SWLEDX8-I2C	16 bit I2C connection to SWLEDX8 card	I2C
TinyPS2	PS/2 keyboard or mouse to TTL Level Serial converter	TTL
VGAX49	VGA Digital Connection (2:2:2 or 5:6:5)	TTL/Analog
SD_CARD_X49	SD Card Adapter	TTL

ODAS Processor Cards

No Data Acquistion System is complete without a Processor Card.

• BLUE-PILL-HUB - STM32 "Blue-Pill Board" based system processor
• ODAS-PSOC5 - Cypress Semiconductor Programmable System on a Chip
• NANO-BKOUT - Arduino NANO GVS Breakout card
• GVSDuino - Arduino UNO compatible GVS Processor card
• UNO-DB25 - Arduino Uno with a DB-25 connector
• DAS-32U4 - Data Acquisition System Processor DAS-32U4

ODAS Card Test Station

• ODAS Test Station
• ODAS Tester - Test Software in GitHub repository
• Arduino Nano
• Cables or loopback connector
• Auto-detect card if test has been run before
• Presents card type list for un-programmed EEPROMs

Checking EEPROM for board type...Detected DIGIO-128 board
R=Read EEPROM, W=Write EEPROM, T=Test DIGIOs, L=Loop Test, B=Bounce LEDs