# Nano clone digital out only drops to 1.3v \[Solved\] **URL:** \ **Category:** General Electronics\ **Created:** [June 2, 2022, 1:14am UTC](https://forum.arduino.cc/t/nano-clone-digital-out-only-drops-to-1-3v-solved/998416 "2022-06-02T01:14:30Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![beamsbox](https://avatars.discourse-cdn.com/v4/letter/b/13edae/32.png) [@beamsbox](https://forum.arduino.cc/u/beamsbox)\ **Post date:** [June 2, 2022, 1:14am UTC](https://forum.arduino.cc/t/nano-clone-digital-out-only-drops-to-1-3v-solved/998416/1 "2022-06-02T01:14:30Z")
I've got a cheapo Nano clone, the digital output of the pin only hits 4.6-4.8v high, but then drops to only 1.3v or so for the low. Just testing really, with the blink example changed for 5 sec on, 5 sec off to allow for reading the voltage. I'm pretty sure this is messing with my circuit - I'm using this as the hv1 input to one of those bi-directional logic level shifters, trying to convert the 5v to 3.3v. what I want to see is Dout goes high, converts to a 3.3v high. Same setup works fine on an Uno. But not the clone nano. The Uno hits 5.1 high, 0 low though. Would the 5.5 hi 1.3 lo be my problem? Would a pulldown resistor on the Dout of the nano properly force it to 0v nd possibly fix my problem? Thx all! ---
**Author:** ![DVDdoug](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/dvddoug/32/671533_2.png) [@DVDdoug](https://forum.arduino.cc/u/DVDdoug)\ **Post date:** [June 2, 2022, 1:26am UTC](https://forum.arduino.cc/t/nano-clone-digital-out-only-drops-to-1-3v-solved/998416/2 "2022-06-02T01:26:16Z")
What's connected to the output pin? Can we see a schematic? What happens when nothing is connected except your meter? I'll look for the output specs, but anything below 1.5V on an **input** is read as low, and anything above 3.5V will read high. In-between is undefined and can read high or low. ...OK, **Output-low should be 0.8V or less at 20mA.** Output high should be 4.1V or more at 20mA. That's with a 5V power supply. More current makes those "worse" (unspecified) and less current makes them "better". That output specs are ALWAYS more strict than the inputs so if you write low you ALWAYS read low (with a connection to a similar device) and if you write high you ALWAYS high. (That's assuming the voltage & current are within spec.) ---
**Author:** ![Wawa](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/wawa/32/1211303_2.png) [@Wawa](https://forum.arduino.cc/u/Wawa)\ **Post date:** [June 2, 2022, 1:56am UTC](https://forum.arduino.cc/t/nano-clone-digital-out-only-drops-to-1-3v-solved/998416/3 "2022-06-02T01:56:06Z")
> [@beamsbox](#): > > the digital output of the pin only hits 4.6-4.8v high Normal behaviour if powered from USB. A classic Nano simply uses a diode for USB backflow protection, which drops about 0.4volt. So VCC of a Nano on USB power is about 5 - 0.4 = 4.6volt. An Uno/Mega uses a more complicated circuit there, with an opamp and mosfet. So VCC is much closer to USB voltage on those boards. Not that it matters for most projects. LOW should be close to zero though. Did you set the pin to output with pinMode. Leo.. ---
**Author:** ![johnerrington](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/johnerrington/32/340106_2.png) [@johnerrington](https://forum.arduino.cc/u/johnerrington)\ **Post date:** [June 2, 2022, 2:01pm UTC](https://forum.arduino.cc/t/nano-clone-digital-out-only-drops-to-1-3v-solved/998416/4 "2022-06-02T14:01:52Z")
> [@beamsbox](#): > > I'm pretty sure this is messing with my circuit How would we know? Can you provide a schematic? > [@How to make a schematic you can post.](https://forum.arduino.cc/t/how-to-make-a-schematic-you-can-post/675103): > > When you submit a question on the forum you will usually need to add a schematic (circuit diagram). The tutorial that follows will explain some ways to create a useful image; however lets start by explaining how to add the image to your post. Its easy. Having created the image all you need to do is : Save the image somewhere convenient - maybe your desktop Start your post, and place the cursor (insertion point) where you want the image to be shown; [upload image to forum] 3: click th… ---
**Author:** ![TomGeorge](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/tomgeorge/32/215261_2.png) [@TomGeorge](https://forum.arduino.cc/u/TomGeorge)\ **Post date:** [June 2, 2022, 4:21pm UTC](https://forum.arduino.cc/t/nano-clone-digital-out-only-drops-to-1-3v-solved/998416/5 "2022-06-02T16:21:29Z")
Hi, > [@Wawa](#): > > Did you set the pin to output with pinMode. > Leo.. Good question. @beamsbox can you please post your code? To add code please click this link; > [@How to get the best out of this forum](https://forum.arduino.cc/t/how-to-get-the-best-out-of-this-forum/679966#posting-code): > > See also [FAQ - Arduino Forum](https://forum.arduino.cc/faq) for general rules on forum behavior and etiquette. Hello, Welcome to the Arduino Forum. This guide explains how to get the best out of this forum. Please read and follow the instructions below. Being new here you might think this is having rules for the sake of rules, but that is not the case. If you don’t follow the guidelines all that happens is there is a long exchange of posts while we try to get you to tell us what we need in order to help you, which is frus… Thanks.. Tom... πŸ˜ƒ πŸ‘ β˜• πŸ‡¦πŸ‡Ί ---
**Author:** ![beamsbox](https://avatars.discourse-cdn.com/v4/letter/b/13edae/32.png) [@beamsbox](https://forum.arduino.cc/u/beamsbox)\ **Post date:** [June 2, 2022, 6:17pm UTC](https://forum.arduino.cc/t/nano-clone-digital-out-only-drops-to-1-3v-solved/998416/6 "2022-06-02T18:17:11Z")
Tom, John, code is not really in question, literally using the blink code example modified for 5 sec, as stated in first paragraph. ---
**Author:** ![beamsbox](https://avatars.discourse-cdn.com/v4/letter/b/13edae/32.png) [@beamsbox](https://forum.arduino.cc/u/beamsbox)\ **Post date:** [June 2, 2022, 6:20pm UTC](https://forum.arduino.cc/t/nano-clone-digital-out-only-drops-to-1-3v-solved/998416/7 "2022-06-02T18:20:01Z")
Dvd and Wawa, thx for the helpful responses. The output is going to one of these bidirectional level shifters. Looks like just a MOSFET. [https://www.google.com/search?q=hiletgo+level+converter+schematic&oq=hiletgo&aqs=chrome.1.69i57j69i59j0i512l8.4179j0j7&client=ms-android-google&sourceid=chrome-mobile&ie=UTF-8](https://www.google.com/search?q=hiletgo+level+converter+schematic&oq=hiletgo&aqs=chrome.1.69i57j69i59j0i512l8.4179j0j7&client=ms-android-google&sourceid=chrome-mobile&ie=UTF-8) ---
**Author:** ![dlloyd](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/dlloyd/32/751911_2.png) [@dlloyd](https://forum.arduino.cc/u/dlloyd)\ **Post date:** [June 2, 2022, 6:37pm UTC](https://forum.arduino.cc/t/nano-clone-digital-out-only-drops-to-1-3v-solved/998416/8 "2022-06-02T18:37:11Z")
> [@beamsbox](#): > > Same setup works fine on an Uno. But not the clone nano. Just to mention that pins A6 and A7 on an UNO can work as digital I/O, but on an Nano, they are analog only. ---
**Author:** ![beamsbox](https://avatars.discourse-cdn.com/v4/letter/b/13edae/32.png) [@beamsbox](https://forum.arduino.cc/u/beamsbox)\ **Post date:** [June 2, 2022, 8:37pm UTC](https://forum.arduino.cc/t/nano-clone-digital-out-only-drops-to-1-3v-solved/998416/9 "2022-06-02T20:37:24Z")
To be a bit more clear, it is this level shifter that only seems to work with the Uno. It passes the 5v digital high from the Uno and converts to a 3.3 v pulse coming out the L1 pin. Same setup but using the Nano, no 3.3v pulse output from the L1 pin. It just remains in the 3.3 v state, as it does when nothing is hooked up to the H1/L1 pins at all. ---
**Author:** ![Wawa](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/wawa/32/1211303_2.png) [@Wawa](https://forum.arduino.cc/u/Wawa)\ **Post date:** [June 2, 2022, 9:13pm UTC](https://forum.arduino.cc/t/nano-clone-digital-out-only-drops-to-1-3v-solved/998416/10 "2022-06-02T21:13:14Z")
> [@beamsbox](#): > > To be a bit more clear You have to do better than that. Some pins of the classic Nano are different. Pin13 is one of them. It has no buffer for the built-in LED, so can give problems when used as input. And there are Nanos and Nanos. I assume you have a 16Mhz classic Atmega328 Nano. But there are many others with different logic voltages. Some dumb-ass called them Nano too. A mosfet level converter is just a switch. How LOW the pin will go still depends on the load on the other side. Leo.. ---
**Author:** ![TomGeorge](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/tomgeorge/32/215261_2.png) [@TomGeorge](https://forum.arduino.cc/u/TomGeorge)\ **Post date:** [June 3, 2022, 2:30am UTC](https://forum.arduino.cc/t/nano-clone-digital-out-only-drops-to-1-3v-solved/998416/11 "2022-06-03T02:30:58Z")
Hi, Have you tried changing output pin on the Nano? Can you please post a image(s) of your Nano? Thanks.. Tom... πŸ˜ƒ πŸ‘ β˜• πŸ‡¦πŸ‡Ί ---
**Author:** ![Paul\_B](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/paul_b/32/216376_2.png) [@Paul\_B](https://forum.arduino.cc/u/Paul_B)\ **Post date:** [June 3, 2022, 6:43am UTC](https://forum.arduino.cc/t/nano-clone-digital-out-only-drops-to-1-3v-solved/998416/12 "2022-06-03T06:43:06Z")
> [@dlloyd](#): > > Just to mention that pins A6 and A7 on an UNO can work as digital I/O, but on an Nano, they are analog only. Are you kidding? 😲 ---
**Author:** ![dlloyd](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/dlloyd/32/751911_2.png) [@dlloyd](https://forum.arduino.cc/u/dlloyd)\ **Post date:** [June 3, 2022, 6:59am UTC](https://forum.arduino.cc/t/nano-clone-digital-out-only-drops-to-1-3v-solved/998416/13 "2022-06-03T06:59:22Z")
> [@Paul\_B](#): > > Are you kidding? 😲 [Nano A6/A7 as Digital I/O - Reference needed](https://forum.arduino.cc/t/nano-a6-a7-as-digital-i-o-reference-needed/856654) ---
**Author:** ![Paul\_B](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/paul_b/32/216376_2.png) [@Paul\_B](https://forum.arduino.cc/u/Paul_B)\ **Post date:** [June 3, 2022, 8:19am UTC](https://forum.arduino.cc/t/nano-clone-digital-out-only-drops-to-1-3v-solved/998416/14 "2022-06-03T08:19:15Z")
So there are actually **two** reasons that A6 and A7 on an UNO can **not** work as digital I/O. 🀨 ---
**Author:** ![beamsbox](https://avatars.discourse-cdn.com/v4/letter/b/13edae/32.png) [@beamsbox](https://forum.arduino.cc/u/beamsbox)\ **Post date:** [June 3, 2022, 1:18pm UTC](https://forum.arduino.cc/t/nano-clone-digital-out-only-drops-to-1-3v-solved/998416/15 "2022-06-03T13:18:31Z")
I have tried different pins. The lowest low I have seen is .8v. Here's the Nanos I have: ![PXL_20220603_130912272](https://europe1.discourse-cdn.com/arduino/original/4X/8/f/1/8f16acdd2112d60279585d7d697b0b33e669d887.jpeg) And here's the converter I have: ![PXL_20220603_131309594](https://europe1.discourse-cdn.com/arduino/original/4X/d/2/3/d23e45e098b8fdb41568d7eb1c58b3a5040a75a9.jpeg) ![PXL_20220603_131322836](https://europe1.discourse-cdn.com/arduino/original/4X/e/b/4/eb4448f0085047c7d33319475db14aea58cd78a7.jpeg) Thanks again. ---
**Author:** ![camsysca](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/camsysca/32/1015228_2.png) [@camsysca](https://forum.arduino.cc/u/camsysca)\ **Post date:** [June 3, 2022, 2:03pm UTC](https://forum.arduino.cc/t/nano-clone-digital-out-only-drops-to-1-3v-solved/998416/16 "2022-06-03T14:03:37Z")
The way I read this thread, you're attempting to use D13 as a digital output feeding your level shifter, while still driving the LED. With cheap Nanos, the LED and it's current limiting resistor may interfere with the levels you measure. You can test this by disconnecting your level shifter and measuring the voltage where you were connecting the level shifter's input, as the LED turns on and off. If that is the case, switch to a different digital pin(for example, D12), and see what voltages appear when the output is high and low. C ---
**Author:** ![beamsbox](https://avatars.discourse-cdn.com/v4/letter/b/13edae/32.png) [@beamsbox](https://forum.arduino.cc/u/beamsbox)\ **Post date:** [June 3, 2022, 3:42pm UTC](https://forum.arduino.cc/t/nano-clone-digital-out-only-drops-to-1-3v-solved/998416/17 "2022-06-03T15:42:20Z")
Using D11 I get close to 5v, but the low is still around 1v... ---
**Author:** ![beamsbox](https://avatars.discourse-cdn.com/v4/letter/b/13edae/32.png) [@beamsbox](https://forum.arduino.cc/u/beamsbox)\ **Post date:** [June 3, 2022, 6:38pm UTC](https://forum.arduino.cc/t/nano-clone-digital-out-only-drops-to-1-3v-solved/998416/18 "2022-06-03T18:38:10Z")
Ummm... I have no idea why, but D10 works. Proper 0v ground on it seems to do the trick. Thx everyone for the help. ---
**Author:** ![camsysca](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/camsysca/32/1015228_2.png) [@camsysca](https://forum.arduino.cc/u/camsysca)\ **Post date:** [June 3, 2022, 7:22pm UTC](https://forum.arduino.cc/t/nano-clone-digital-out-only-drops-to-1-3v-solved/998416/19 "2022-06-03T19:22:52Z")
Any chance you've drawn too much current from D11 in the past? The output current is 40 mA absolute max; an LED from output to 5V or ground, without a limiting resistor, will draw that...for a moment or two. C ---
**Author:** ![beamsbox](https://avatars.discourse-cdn.com/v4/letter/b/13edae/32.png) [@beamsbox](https://forum.arduino.cc/u/beamsbox)\ **Post date:** [June 3, 2022, 11:13pm UTC](https://forum.arduino.cc/t/nano-clone-digital-out-only-drops-to-1-3v-solved/998416/20 "2022-06-03T23:13:17Z")
Possibly but I doubt it. Just put the bootloader on this chip before playing with it. And all my prototyping LEDs already have resistors soldered to em. But can't say definitively, I've been known to do that in the past... Plus I tried multiple Nanos...same-o same-o. [Next page](https://forum.arduino.cc/t/nano-clone-digital-out-only-drops-to-1-3v-solved/998416.md?page=2)