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OWADC1 - 1-wire 8-channel ADC board

Introduction

OWADC1 (w/o) connector J1/J2

OWADC1 is a small, compact board designed by M.Traxler and S.Voltz (GSI/EE) to provide an 8 channel, max. 16bit ADC to be accessed by 1-wire protocol

Documentation

Layout

1-wire ADC

Family code Device and datasheet
20h pdf DS2450 1-Wire Quad A/D Converter

RC time

The inputs of the ADCs have capacities of 100 nF connected to GND ( C15 ... C22 ).
  • Apparently the input resistance of the ADC seems to be around 1010 Ω, therefore the time constant τ is around 1000s, improving noise resilience, but reacting quite slow to rapid changes.
    • NOTE: we deduced those numbers the other way around: having 100nF, we saw a decay time of a 3V input value (~36000 adc counts) to 0 less than 1000, to take more than 10 minutes. Details on purpose.
    • The datasheet says: 1MOhm.
  • To decrease τ smaller capacities should be used.

known 1-wire IDs

Board Number/Name/ID Position ID user
I U1 205607100000001A HADES magnet
U2 ---

new list/new numbers
Board Number/Name/ID Position ID user
       
   
001 U1 20CE0210000000D8  
U2 20D6021000000022
002 U1 20011C10000000BD  
U2 20D62B1000000029
003 U1 20832E100000003E  
U2 20D7021000000015
004 U1 20340710000000B7  
U2 20F81B1000000008
005 U1 207A2E10000000DA  
U2 20792E1000000083
006 U1 20520710000000C6  
U2 20380710000000CA
007 U1 20E814100000003C  
U2 203E071000000078
008 U1 20CD2B100000008A  
U2 20051C1000000061
009 U1 20DC14100000000D  
U2 20D41410000000AC
Board Number/Name/ID Position ID user
010 U1 20C0C30F00000086  
U2 20D2C30F000000B3
011 U1 2058C70F00000089  
U2 20C0C90F0000003B
012 U1 200B9F0F00000055  
U2 2037A70F0000007F
013 U1 20609F0F0000006E  
U2 20ADC30F0000000F
014 U1 201A9F0F00000039  
U2 20679F0F000000EB
015 U1 20BDA60F00000097  
U2 20279E0F00000053
016 U1 20D4A80F00000060  
U2 20FBC00F000000DD
017 U1 202FC90F00000036  
U2 203FA70F000000DE
018 U1 20E8C30F00000091  
U2 202CC90F0000006F
019 U1 20989E0F00000070  
U2 20FFC40F0000001E
Board Number/Name/ID Position ID user
020 U1 20799C0F000000ED  
U2 20DFC10F0000007A
021 U1 2050C50F000000AB  
U2 20149F0F0000002A
022 U1 2062C70F000000AB  
U2 2065C70F0000002E
023 U1 20F4C30F000000B7  
U2 205CC70F00000055
024 U1 20139F0F000000AF  
U2 2046C50F00000042
025 U1 204AC50F0000003F  
U2 20579F0F00000006
026 U1 2056A10F00000017  
U2 20F0A80F0000000A
027 U1 20E8A80F000000F0  
U2 20DCC10F00000023
028 U1 20E5C10F00000058  
U2 20FBC30F00000093
029 U1 20EEC30F00000023  
U2 200C9F0F000000D0

Notes and Remarks

  1. Make sure to have (at least) 1 pull-up resistor of about 3.3kΩ on the data line of the 1-wire bus to the power VDD.
    • Recommended to have it at the master, e.g. at HadCon's connector JDINOUT2.

Future/Extensions/Wish list

  • 10 pin 1-wire connector:
    • pin layout compatible to JDINOUT of HadCon and HadCon2
    • but with a switch/dial (?) to connect internal 1-wire bus to one of the available 6 positions
    • switch for allowing/blocking (default) connection to external VDD of HadCon(2)
    • alternative:
      • 2 pin connector (screws/clamps) connecting only data and ground line
  • RJ-45 connectors
    • 90° bending

Applications


-- PeterZumbruch - 2017-Feb-09
Topic attachments
I Attachment Action Size Date Who Comment
OWADC1.jpgjpg OWADC1.jpg manage 577.2 K 2011-08-04 - 12:43 PeterZumbruch OWADC1 (w/o) connector J1/J2
OWADC1.pdfpdf OWADC1.pdf manage 46.7 K 2011-07-19 - 20:45 MichaelTraxler Schematics of OWADC1
Topic revision: r12 - 2017-02-09, PeterZumbruch
 
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