Assembling Two PCBs: A Cautionary Tale of Patience and Persistence

In my attempt to build two ESP32-C3 based projects, I discovered that having multiple boards on hand was a wise decision. This was not only due to the fact that one board did not function as expected, but also because it allowed me to troubleshoot and iterate without significant setbacks. As soon as all the SMD components were in place, it was time to reflow the PCBs and that is where problems for me started. The issue was that the PCBs were too big for my hot plate.

However, after heating up both sides of the PCBs and doing some additional reflow work with my hot air gun and soldering iron, I was able to overcome this hurdle. This process took a significant amount of time, but ultimately yielded positive results. The end result did not look half bad, considering it had taken several hours to assemble. Before programming the boards, I first had to update my ESP32 boards library to include the ESP32-C3 and install all the necessary libraries that Ovidiu utilizes.

After completing these updates, I was happy to find out that the code for the first board uploaded without a problem. On the other hand, the second board was not recognized by the computer, which is where the package of the ESP32-C3 comes into play. This is because you cannot see whether the soldering process worked out fine, and the board did not feel like working with me. In an attempt to troubleshoot this issue, I reflowed the soldering a few times, but ultimately had to replace the microcontroller.

To my surprise, the second board functioned without a problem once it was properly reworked. This experience taught me the importance of patience and persistence when building projects, especially those involving complex electronics like the ESP32-C3. Navigating through the User Interface is pretty intuitive, even though not all button presses get recognized by the system.

The measurement functions on both boards worked perfectly fine, with good accuracy and the USB Ports for measuring did also work. Another significant feature of these boards is the energy calculating bug, which does not exist in this project. The battery voltage is visible at all times, and the battery charging and protection functionality works just fine as well.

The SD card logging function on both boards worked without any problems, and I liked the way Ovidiu made his code because it is really easy to browse through and understand unlike some of the code I published before. One aspect that was missing from these boards at this point was an efficiency mode that basically uses one channel for the input power and another for the output power. This feature would allow us to calculate the efficiency of, for example, a buck converter.

Unfortunately, due to time constraints, I only managed to implement this feature halfway. I would love to see it become a standard feature in future projects. The only real negative aspect of these boards is that despite looking like they could work with only a USB input, you should always power them with a battery. This is because the TP4056 battery charging IC still creates a hear-able oscillation while doing so without a battery on its output.

Finally, I would caution absolute beginners from attempting this project due to the difficulty in soldering some of the ICs and the ESP32 itself. Other than that, overall, I really enjoyed the project and am giving it an 8 out of 10. I am looking forward to using these boards in other videos if you are interested in building one yourself then here are all the main information and of course, you can find more in the video description.

With that said, I hope you enjoyed this video and if you did, don't forget to like, share, subscribe, and hit the notification bell. Stay creative, and I will see you next time.

WEBVTTKind: captionsLanguage: enSo this is my old Power Meter/Logger project that I created half a decade ago. And even though its perfboard construction with all the hot glue snot does not look  very appealing; I would nowadays still say that such a project is pretty handy to have around. Because by simply putting it in series to your power source and load you can see exactly  what voltage and current it demands and thus what power and energy it requires over time. This gets especially interesting if you want to determine for example how much  power/energy your custom project needs, how much energy it takes to fill up your  brand new powerbank or if you want to see what you solar panel is capable of. The only problem with my power meter is that overtime I noticed that there is actually a bug  in the code that deforms the calculated energy.And nowadays there also exist commercial  solutions that can do a bit less but still enough for most people. So building my exact project does not make that much sense anymore;  but luckily a viewer of mine created a remake of the project which comes with tons of improvements. So in this video I will try to build his project, test it out and ultimately score  it on a scale from 1 to 10 to let you know if you should consider building it as well. Let's get started! This video is sponsored by JLCPCB who produced the  PCBs for this project which like always were flawless regarding their quality.  And now they can even do upto 20 layer design for still an unbeatable price.  If you are interested then upload your Gerber files today to order your professional PCBs. Now first off let me tell you that all the files for this project are available on  Hackaday and that is where I also downloaded not only the code but also the EasyEDA files. To use them I obviously had to sign into EasyEDA and then opened  them as a schematic and as a PCB design.And just like that with very little effort  we got our finished schematic and PCB which at this point we could customize if we want to. But since I was not interested in that I instead firstly had a closer look at  the schematic to see what changed.The heart of the system is this time  an ESP32-C3 which looks like this and is a big step up from the Arduino Pro Mini I used before. Basically put; it is fast, comes with more storage and way more features including WiFi,  Bluetooth and even an integrated Real Time Clock. Another cool feature comes to mind when comparing it to ESP8266 or ESP32  development boards that I used before.Those boards always come with a small  USB to Serial Converter so that your computer and microcontroller can talk to one another  which also means it is mandatory for programming the microcontroller. This new ESP32-C3 apparently though does not need such a converter and instead can directly  connect to a USB C Ports data pins like shown here, very handy and saves us money. The only thing I didn't like about this microcontroller was its package with  the pins only accessible from the bottom but more about that later.And in case you were wondering what these 5.1kohm resistors are doing at the CC1 and  CC2 pins of the USB-C port then firstly let me show you what happens when not using them. As you can see when using a normal USB A to USB C cable then we get  our desired 5V power from which can also draw quite a bit of current. But when using a USB C to USB C cable then we get absolutely no voltage at the USB port. So the two small resistors are required for the power supply to know that it is  supposed to output 5V and as you can see they seem to do their job perfectly fine. But moving on to the second big change which is this INA3221  IC which is a Triple-Channel Measuring IC.In comparison to my old design that utilized  the INA219, this new one can basically measure 3 current paths while my old one could only do one. And when saying current path I of course mean measuring a voltage drop across a defined current  shunt which then allows us to calculate the flowing current, the power and also the energy. And if you are thinking to yourself: „What is the point of measuring more than one power  source and load“ then let me tell you that there are certainly situations for that which is why I  build my old design twice over the years.OK; now to end the schematic part let me  just say that all required decoupling and filter capacitors were in place,  I love that he included a USB A and USB C port for one input channel, we got a Micro  SD Card port for logging like before, we got a bigger TFT LCD which I really like and even a  full blown LiPo battery support with charging IC, protection ICs and voltage divider for monitoring  and of course also a voltage regulator to get fitting 3.3V to power everything. So yeah after closer inspection I spotted no problems on neither the schematic nor the  PCB side of things which is why next I ordered my PCBs through JLCPCB along with a stencil for later  spreading the solder paste for a fantastic price.And while doing that I also shopped on LCSC to get  all of the required components and after a week of waiting everything arrived at  my place and it was time for the assembly.To do that I simply positioned the stencil  on top of a PCB and spread the solder paste all over and through its fine holes. Then all I had to do was placing all of the SMD components onto the correct spots on the  PCB and to help you with that I would recommend checking out the BOM file for the PCB and you can  also search for specific components on it.By the way I am assembling two PCBs here  just in case one doesn't want to work and in hindsight that was definitely the right move. Because as soon as all the SMD components were in place it was time to reflow the  PCBs and that is where problems for me started because the PCBs were too big for my hot plate. But after heating up both sides of the PCBs and doing some additional reflow work with my hot  air gun and soldering iron, it was time for the easy part and that was inserting all THT  components and soldering them in place.So after 3 hours of work the end result  didn't look half bad but before programming the boards I firstly had to update my ESP32  boards library so that it does include the ESP32-C3 and I also had to install all the  libraries the code of Ovidiu utilizes.But after that I was happy to find  out that the code for the first board uploaded without a problem.On the other hand though the second board was not recognized  by the computer and that is where the package of the ESP32-C3 comes into play  because you can not see whether the soldering process worked out fine. So I did a bit more of reflow soldering and eventually even replaced the microcontroller  but no matter what I did this board didn't feel like working with me. That is why I was very happy that I made two boards because the second one functioned  without a problem; so let me begin telling you the positive aspects of this project. Navigating through the User Interface is pretty intuitive even though not all  button presses get always recognized.The measurement functions all worked  perfectly fine, came with good accuracy and the USB Ports for measuring did also work. And needless to say the energy calculating bug does not exist in this project. I also really like that the battery voltage is visible at all times and of course the  battery charging and protection does all work just fine as well. Last but not least the SD card logging functioned without any problems and I  liked the way he made his code because it is really easy to browse through and understand  unlike some of the code I published before.The only thing missing for me at this point  was an efficiency mode that basically uses one channel for the input power and another  for the output power and thus we can calculate the efficiency of for example a buck converter. I tried implementing this feature by myself but I kind of ran out of time and thus only  got it halfway implemented; so I would love to see this happen in the future. And the only real negative aspect of this board is that despite looking  like it could work with only a USB input, you should always power it with a battery. I mean it does work with only USB power but then you will have to endure this noise all the time. The reason for that is the TP4056 battery charging IC which without a battery on its output still  creates the 4.2V to power everything but it also creates a hear-able oscillation while doing so. And the last thing for me which is a tiny bit negative is that some ICs and like I  already said the ESP32 is kind of hard to properly solder so I would not recommend  this project to an absolute beginner.But other than that overall I really  enjoyed the project and that is why I am giving it an 8 out of 10 and I am  looking forward to using it in other videos.If you are interested in building one yourself  then here are all the main information and of course you can find more in the video description. With that begin said I hope you enjoyed this video and if you did then don't forget to like,  share , subscribe and hit the notification bell.Stay creative and I will see you next time.