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OWADC1 - 1-wire 8-channel ADC board


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



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 seem 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

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

-- PeterZumbruch - 09 Mar 2012
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
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Topic revision: r9 - 2012-03-09, PeterZumbruch
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