auou1i Posted August 5 Share Posted August 5 Hello  I am looking at purchasing a number of Shelly uni plus devices for a project. If I supply power to the device at 12VDC, what is the minimum voltage that the digital input would need to see to register a logic high?  If I provide 4.5VDC into the digital input, will this register as logic high or true?  Also does the device have a dry contact output that can be triggered via wifi?  Quote Link to comment Share on other sites More sharing options...
Shelly Olsche Posted August 5 Shelly Share Posted August 5 Digital inputs triggering voltage: 1.5 V (active low level) 2 potential-free contacts solid-state relay outputs - OUT1 and OUT2 more infos you will finde here: https://kb.shelly.cloud/knowledge-base/shelly-plus-uni  Quote Link to comment Share on other sites More sharing options...
auou1i Posted August 5 Author Share Posted August 5 sorry for my ignorance what does active low level mean? Does that mean anything over 1.5v will register as a logic high or true ? Quote Link to comment Share on other sites More sharing options...
Members thgoebel Posted August 5 Members Share Posted August 5 (edited) As other Shelly actuators, the inputs of a Shelly UNI plus are activated by a small (36μA) current flowing from IN-x (or COUNT IN) to GND. Is this current smaller than approximately 15μA, the input is disengaged. Thus, there are no high and low levels in voltage. But you may arrange pull-up or pull-down resistors according to Ohm‘s law to detect a peculiar voltage level. Edited August 5 by thgoebel 1 Quote Link to comment Share on other sites More sharing options...
auou1i Posted August 5 Author Share Posted August 5 Thanks for the response. Are there other Shelly devices with a digital input and volt free outputs controllable over wifi? I have used Shelly 1s a lot, but my understanding is that you need 12v (or the same voltage as what is powering the Shelly) to enable it to detect the a switched input (on the SW terminal) Quote Link to comment Share on other sites More sharing options...
Members thgoebel Posted August 5 Members Share Posted August 5 5 hours ago, auou1i said: Does that mean anything over 1.5v will register as a logic high or true ? As @Olsche mentioned before: Inputs are active low. Hence, voltage larger than 1,5V (with an appropriate pull-down resistor of 1 to 10kΩ) will produce a logic „zero“ - input is inactive. And vice versa… Please be aware this is not contradictory to my explanation about input current! Quote Link to comment Share on other sites More sharing options...
Members thgoebel Posted August 5 Members Share Posted August 5 4 minutes ago, auou1i said: Are there other Shelly devices with a digital input and volt free outputs controllable over wifi? Shelly plus 1 (SELV compliant) Shelly Mini 1 (NOT SELV compliant) Shelly pro 1, pro 2 and pro 3 (SELV compliant) 6 minutes ago, auou1i said: but my understanding is that you need 12v (or the same voltage as what is powering the Shelly) to enable it to detect the a switched input (on the SW terminal) Sorry to disagree. As mentioned above, all Shelly actuators have the same circuit behind terminal(s) SW (or IN-x): Â Â Quote Link to comment Share on other sites More sharing options...
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