Open Data Acquisition System

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DIGIO32-I2C P1994 720px.jpg

Features

  • This document is the ODAS (Open Data Acquisition System) card design specification
  • ODAS features a powerful combination of Open Hardware and Open Software
    • ODAS form factor is an open form factor which provides an inexpensive and small card size (approx 4" square)
  • Standalone use or control low level hardware interfaces from a Host Computer
  • Mix and match card types

ODAS System Block Diagram

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

The block diagram is:

ODAS Block Diagram.png

Maximum Configuration

  • MCP23017 (16 port I/O expander) uses (1) I2C address in range 0x20-0x27
  • I2C supports up to 8 MCP23017 I2C addresses typically
  • Up to 64 cards can be supported with a single [I2C-RPT-08|8 port I2C repeater]]
  • Up to 8 of 8 port I2C repeaters can be used

Open Hardware

Mechanicals

  • Standardized form factor and mechanicals
  • Two basic form factors
    • 95x95mm
    • 49x49mm
  • Adapter to allow both form factors to be used
    • Solid mounting holea
    • 95x95mm has (4) 6-32 holes
    • 49x49mm has (4) 4-40 holes

95x95mm Form Factor

  • 6-32 screw holes in each corner

ODAS 95mm Mechs.PNG

49x49mm Form Factor

  • 4-40 screw holes in each corner

ODAS 49mm Mechs.PNG

Mixed 95x95mm and 49x49mm cards

P1748-CROPPED-720PX.jpg

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

  • Useful when there are a lot of I2C cards in a system
    • Useful in card test
    • Configure the card once, autodetect later
  • EEPROM I2C base address = 0x50
    • I2C address offset (0x50-0x57) set by jumpers for MCP23008/MCP23017 I2C port expanders
  • 24LC024 EEPROM
    • 256x8
    • 2.5-5.5 V
    • Maximum Clock Frequency: 400 kHz
    • Supply Current - Max: 3 mA
  • Based on Raspberry Pi Hat Spec
struct eep_vals
{
  char signature[4]; // 0-3 - "ODAS" in ASCII
  byte fmt_version;  // 4 - EEPROM data format version (0x00 reserved, 0x01 = first version)
  byte rsvd;         // 5 - set to 0
  short numatoms;    // 6-7 - set to 2
  long eeplen;       // 8-11 - set to 96 dec
  byte uuid[16];     // 12-27 - "0000000000000000" in ASCII
  short pid;         // 28-29 - See PID table
  byte vslen;        // 30 - set to 32 dec
  byte pslen;        // 31 - set to 32 dec
  byte vstr[32];     // 32-63 - Vendor Null terminated String
  byte pstr[32];     // 64-95 - Product Null terminated String
};
  • Addresses 96-255 are user programable
  • Addresses 0-95 can be changed by user (if desired)

Product ID Table

Signature=ODAS
Vendor=land.boards.com

ProductID (in dec)	Product (string)
1			DigIO16-I2C
2			DIGIO-128
3       		DIGIO-128/64
4			OptoIn8-I2C
5			OptoOut8-I2C
6			DIGIO32-I2C
7			PROTO16-I2C
8			ODAS-PSOC5
9			ODAS-RELAY16
127     		NEW CARD

Drivers

Arduino

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

Firmata test screenshot.png

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

RPi-I2C-DIGIO-128-clk-data.png

  • Overall timing - 1 cycle

RPi-I2C-DIGIO-128-overall-read-1cycle.png

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

RPi-I2C-DIGIO-128-overall-rmw-2cycles.png

ESP32 MicroPython Drivers

PyBoard MicroPython Drivers

Cards

  • Various cards
    • Processor cards
    • Digital I/O cards
    • Optoisolator cards
    • FPGA cards

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 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 FPGA Cards

ODAS Opto-Isolated Cards

OptoIn8-I2C-X3-CCA-5456-720px.jpg

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.

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
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