kopimojo

ESP32-S - The esp32-cam board was based on esp32-s. I purchased a few of these together with some PCB adapter boards. I have a few hours to spare last weekend and used them to do some soldering works. The esp32-s module is tiny and the output connectors are close together. I have five modules to be soldered to the PCB adapter boards. I would be very happy if mange to have three in working order when I am done. The first thing I did is to change the tip of my soldering iron. I changed to a knife-edge tip. The temperature was set to 500℃. The idea is, to solder the contact points by dragging the knife-edge tip of the soldering iron, in one go. I will try to use a minimum amount of tin on the knife-edge. It helps a lot to apply soldering flux to the contacts points first. The esp32-s and the PCB adapter board securely held together using the crocodile clip of a third arm tool. I took the time to adjust the alignment of the contacts points before starting to apply soldering tin....

Simplicity - Simplicity in design has its practical value. I was designing a freeform wire-frame structure for esp32-cam. I made an elaborate freeform that was not very successful. The esdp32-cam keep dropping WiFi packets. I can not get a whole frame sent over to a web client without losing 75% of the frame. What more, the position and orientation of the esp32-cam were too critical for stable operation. I effectively design a faraday cage for the esp32-cam. When I realize this, I need to rethink my design. I must not cage in my esp32-cam in a wire-frame. I need a simpler design. I end up with a very simple design, where the esp32-cam hang above a cube-based structure. Now, this design works better than the previous one. An elaborate design does not mean better. There are a lot of non-visual parameters one must consider to make things work. I am learning the lesson. Less is better than more. Simple is better than complicated. This applies to almost everything in life, especiall...

Stability - My esp32-cam setup is working, but not stable enough. I experienced Wifi signal dropout and intermittent reboot. I have a hunch it was due to brownout. The setup was more stable operating with 9V battery than with power adopter. I was running the esp32-cam board with 3.3V and yesterday I reconnect the import power terminal to 5V. Guess what, now the setup run with acceptable stability and am happy. If your esp32-cam setup is running unstable then use 5V to power up your board. Last week,  I received "Mini Dc-dc 12-24v To 5v 3a Step Down Power Supply Module Voltage Buck Converter", ten pieces of them. Yes, I know it says 12-24V but I succeeded to use the buck converter with 9V battery without any problem. I got 4.5V at V0+ terminal when I soldered the converter to a fix output voltage of 5V. I can get close to 5V when using adjustable operational mode. The negative battery terminal is connected to the GND and the positive to the IN+. I run an uasyncio...

CAT - Cats dancing outside of my window. What a racket they made. I have to put up with these for another few months. They need to dig deeper. An eight storeys apartments block will be ready in 2022. Oh well! These are the type of ESP32-CAM boards I was working with. The one on the right marked with DM was not working. I was not able to flash micropython to it and was not able to connect with it using esptool. I can see some output from it using picocom. I am interested to know if someone has had success working with DIY MORE board. I have managed to build micropython with camera support from the latest revision of micropython from GitHub . People at micropython.org are doing a great job in providing firmware for different types of  ESP8266 and ESP32 boards. But, I can not see firmware for ESP32-CAM though. I did my compiling works on a Linux Mint machine. You have to install all the necessary tools to be able to compile. I uploaded the newly compiled firmware to my GitH...

Freeform - The esp8266 ssd1306 OLED freeform setup is now ready. I need to practice soldering more. Even though the freeform circuit is somewhat useable but it is not nearly as beautiful. If any of you would like to try, I would like to advise you using female header pins as modules holder. You solder the header pins in proper places to the freeform wireframe according to your design. In that way, you will not unintentionally destroy your module boards should mishaps happened. Hopefully, after some more practice, we will produce some nice looking freeforms  fit for art exhibitions. As I mentioned earlier, images taken by the esp32-cam needs to be downsized and converted. We need to change 1600x1200 JPG down to 128x64 PBM. I will do the whole process automatically in the finished product. The code below seems to work OK. #!/usr/bin/python3 from PIL import Image, ImageEnhance foto = Image.open("foto.jpg") # crop foto = foto.crop((0,200,1600,1000)) # convert foto = foto...

Soldering - I need to do some soldering work today. A few esp development boards need header pins. Please sit near an open window while working with soldering iron and tin. Solder tin and flux fumes are not healthy. I tend to hold my breath while soldering. There are different types of esp development boards. Today I soldered header pins onto a few of them. Nothing fancy.  I have to flash MicroPython to their flash memory after soldering is done. I want to test using ssd1306 OLED to show an image. The idea is to snap a picture using an esp32-cam and show the image to an OLED connected to an esp8266 situated at a different place. The problem is that the image capture is 1600x1200 jpg while the OLED that I will be using will only take a 128x64 pbm format. Somewhere between image capture to image display, a downscaling, filtering, and conversion, need to be done. I am using Python PIL module on a Linux desktop to do the heavy job of processing a captured image. I did thi...

Batteries - A fully charged 9V 400mAh managed to drive the esp32-cam  AP mode for 1hr 35 min STA mode for 2hr 5 min So it seems that AP just need a bit more power than the STA mode. The AP mode is especially interesting when we want to have a mobile webcam server mounted on a robot car or perhaps a flying drone. Using an Android or iPhone one can connect to the AP and stream the picture frames to her phone. We can also install "out in the field" webcam server using AP mode of esp32-cam, for example, greenhouses and farms. Esp32-cam can operate in both AP and STA mode. This provides us with the opportunity to build a socket-based network of esp32.  I have uploaded simple experimental webcam servers to the GitHub.