Open Source EMDR Machine #4. Breadboard layout and Schematics

RE: Open Source EMDR Machine #4. Breadboard layout and Schematics

ilvyanyatka — Mon, 19 Apr 2021 08:38:24 GMT

Hi Enrique,

Wow, I didn't know that! I thought limitations are the same as other Arduinos have. Where can I read about it more?

I was testing my LED functionality, powering it from 3.3V pin and everything was working fine. I assume it was totally save based on (other Arduinos) specs - 200 mA max for 3.3V pin and the fact that I have only 1 LED on at any given time.

Then I added code for Bluetooth, using ArduinoBLE library. On the first upload ,or maybe the first run after upload, (I got distracted so I missed the exact time) my Arduino Nano hangs. One LED stays On all the time and not moving. When disconnecting/connection Nano again I get the same result. I tried to reupload the code both though ArduinoIDE and Eclipse but no success - IDEs hang for good 5-10 minutes with the message "Uploading", and then return me generic error "Error happened when uploading".

So I assumed my Bluetooth code burned the board somehow. I think more correct English word will be "fried". I am clueless how exactly though.

Now, after your comment, I have a question: I was planning to power my Nano from old computer PSU unit, putting 5V on Vin. Is it safe? If not - is it safe to power it with 3,3V on Vin? What about Powerbank (I assume any USB cable connected to it will give me 5V)? I really don't want to power it from a computer.

Thank you!

RE: Open Source EMDR Machine #4. Breadboard layout and Schematics

javagoza — Mon, 19 Apr 2021 08:09:20 GMT

Victoria, I'm sorry about your Arduino Nano 33 IoT.

When you say you've burned the board, what do you mean? What are the symptoms?

Have you taken into account in your design that the Arduino nano 33 IoT does not tolerate 5v? The Arduino NANO 33 IoT microcontroller runs at 3.3V, which means you should never apply more than 3.3V to your digital and analog pins.

It must have care to connect the sensors and actuators to ensure that this limit never exceeds 3.3V.

Connecting higher voltage signals, such as the 5V commonly used with the other Arduino boards, will damage the Arduino NANO 33 IoT.

Also note that the maximum current per pin is 7 mA compared to 40 mA on other Arduino boards.

RE: Open Source EMDR Machine #4. Breadboard layout and Schematics

fmilburn — Mon, 19 Apr 2021 00:48:42 GMT

The one I am using is called the DFPlayer Mini, a link can be found here: https://wiki.dfrobot.com/DFPlayer_Mini_SKU_DFR0299

An identical, or near identical version is sold by others and I got mine on Amazon. It can be used in stereo or mono modes. I'm using mine mono on an Arduino MKR1010 and using hardware serial but software serial should work. The schematic for my project is in this post: make robot friend. Bender | element14 | Cheer Us Up

To use mono (like I did) wire it up between what is marked SPK1 and SPK2 on my schematic. For stereo use two speakers and hook them between SPK1 and GND, and SPK2 and GND.

I am happy to help further if I can and good luck on your project [View:/resized-image/__size/16x16/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-d5d47ec0-58b4-4513-80ca-41b35dada386/8883.contentimage_5F00_1.png:16:16]

edit: for some reason the link to DF Robot doesn't seem to work. But do a google search for DFPlayer Mini and you will find it.

RE: Open Source EMDR Machine #4. Breadboard layout and Schematics

fmilburn — Sun, 18 Apr 2021 21:24:47 GMT

Are you having a problem with the DFPlayer? I used it successfully on a recent project so just curious but perhaps could help if you ran into an issue.

RE: Open Source EMDR Machine #4. Breadboard layout and Schematics

cjodrey — Sun, 18 Apr 2021 20:08:36 GMT

Nice schematics!