 | | Re: Pull Up Resistor
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| (...) The sensor connectors on the HB already have pullup resistors on the signal inputs (as I recall they were 47K), so you shouldn't need to add an additional pullup. If you want to make sure, just check the signal connection with a voltmeter to (...) (26 years ago, 5-Aug-98, to lugnet.robotics.handyboard)
| | | | | Pull Up Resistor
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| Hi, The polaroid documentation mentions that a 4.7K resistor should be placed between ECHO and Vcc. Should this be done when interfacing to the HB? Thanks, Sheridan (26 years ago, 5-Aug-98, to lugnet.robotics.handyboard)
| | | | | Re: Pull Up Resistor
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| I checked the ECHO signal and found it to be at 2.0V when plugged into TIC3 on the HB. I also applied a pull-up resitor which did send ECHO to 5V when not pinging. However, in both cases, I still had seemingly random positive and negative values (...) (26 years ago, 6-Aug-98, to lugnet.robotics.handyboard)
| | | | | Re: Pull Up Resistor
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| (...) I just checked my copy of the Polaroid Sonar Module documentation, and it does in deed state that the module can sink up to 0.1 mA when ECHO is pulled high. It sounds like your module is drawing around 0.064 mA = ((5V - 2V)/47Kohms), so it is (...) (26 years ago, 6-Aug-98, to lugnet.robotics.handyboard)
| | | | | Re: Pull Up Resistor
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| (...) One more thought. I assume you are using a seperate supply (of some sort) for the Sonar module, so be sure to tie the pullup to the HB's +5V! Rick (26 years ago, 6-Aug-98, to lugnet.robotics.handyboard)
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