Recently my daughter brought a journal from the local library. There was a bug bot my daughter said she wanted to make and it was dead simple. There was just one problem with that – I did not get how it could work at all – there was just a solar cell and the vibration motor just connected directly. The motor needs like constant 60mA of current, how is that possible that a tiny solar cell can provide that?
So I ordered cheap motors and cheap solar cells from a you-know-the-name website and guess what, it did not work.
At some point I got the cheap lamp from amazon, it costs about 12$ but worked surprisingly well till some point… Looking under the hood revealed some ugly solutions:
Task: To study the possibility of using of the DIY touch capacitive sensor on the pcb
Tools: PIC18f1230, a pcb with exposed square copper areas
So long story short, my cheap amazon lamp did not survive for a long time, but I really did like the LED light it gave. In the article below I will describe how to use a copper pad and the pic microcontroller without much additional circuitry.
Recently, I was constantly struggling with the fact that microchip was removing more and more support libraries, so it was not wise to rely on them in all projects. Anytime I return again to my old functions – if it used the support libs, there is a pretty good chance it is screwed.
So this code works with XC8 version 2.36 and doesn’t require the involvement of extra support lib.
The project which unfortunately was not finished due to my relocation to other country and taking such a project with me certainly would raise some question at the security control 🙂
When I started to dig into USB topic it was quite a surprise, the amount of efforts the smart people around the world put into it just unbelievable. Even more fascinating fact – it actually worked out. The excitement reached some saturation when I realized the prices (: Vendor ID will cost you 5 grands per year, want to use a USB logo – no problem, just add another 6 grands on the top. Now we could test the compliance of your device with our standard for n grands… The companies using USB are listed on the website www.usb.org (USB Implementers Forum – USB-IF). The curious one could just count a number of companies and calculate the profit just from the year subscription, and this thing is going on for a long long time already. Well they have definitely built an addictive stuff. I, personally, have found the usage for my projects a bit excessive, I definitely not ready to put 5 grands per year for USB in the cheap humidity sensor.
Now, there are tons of different information, it is really challenging to grasp all at once, I will be honest and won’t pretend that I got everything, have a lot of holes in the knowledge, I just need to make it alive and respond to my commands. So, what I gonna to do is to show the info which looked important to me and then will conduct two experiments on this “foundation”.
I was working on a small project where I needed to catch a certain button pressed event. Sounds simple initially, but I have 10 such buttons and it means that I need to have 10 IOs, or port expander, or make a digital matrix button handler (like 3×4 keypad) but these all variants are boring, I wanted something more interesting and make something like a DAC based on these buttons which will be digitazed by the built-in ADC in pic18f14k50. Thus, we will use a single port instead of 10, by cost of the more complicated code.
Let me start as usual – from reading of the datasheet.
Sometime ago, I developed the code for interactions with the humidity sensor DHT11. Also, I had used the same code in one of my projects and I was not particularly happy with reliability of this sensor. That’s why I decided to try DHT22 in case if I would use it in some future project.
