5V powered 100LED circuit was consuming around ~1.8Watts(though 5.1Ohm series resistor was really hot) and the brightness of the LED’s were not bad, especially difference between first led and last led brightness didnt bother me it was hardly noticeable when seen from distance. So I decided to use them as a christmas decoration for my garden.
I wanted to use them with battery-bank as there was no power-outlet readily available(for the safety of my children, i would avoid any 230v circuit in my garden especially in wet weather). Also I wanted them to be switchable remotely to avoid going out in the freezing cold. Hence this is what i came up with.. an “ESP-12F based USB-5V switcher”
The Answer is Not a Flippant: Carefully!
Author’s note: A friend in VK4 land made an inquiry about CW operation. I find that 99.99% of my operating time is SSB. But others spend a greater time on the air using CW so why not share some info and data that I have stashed on my computer where a SSB rig can be made to work CW. This also open the possibility of filter switching for a more narrow pass band. With Arduino anything may be possible.
For some projects it is not possible to have the device under debug available on my desk: the board might be in another room, on another site or in a place where physical access is not possible or even dangerous. In that case an IP-based debug probe (see Debugging ARM Cores with IP based Debug Probes and Eclipse) is very useful: as long as I can access its IP address, that works fine. It is an excellent solution even if the board is moving or rotating: hook it up to a WLAN access point and I still can use it as it would be on my desk.
I always wonder whether it is possible to make an amplifier of class D on ATtiny13 or not. Some time ago I found George Gardner’s project based on ATtiny85 – TinyD. It was a sign to start challenging it with ATtiny13. It took me a few hours but finally I made it! The code is very short and useses a lot of hardware settings which has been explained line-by-line in the comments. The project runs on ATtiny13 with maximum internal clock source (9.6MHz). It gave me posibility to use maximum of hardware PWM frequency (Fast PWM mode).
The VEML6075 senses UVA and UVB light and incorporates photodiode, amplifiers, and analog / digital circuits into a single chip using a CMOS process. When the UV sensor is applied, it is able to detect UVA and UVB intensity to provide a measure of the signal strength as well as allowing for UVI measurement.
There are many ways to measure radioactivity level, semiconductor detectors sense interactions between ionizing radiation and p-n junction. Because in hobbyist area most popular are Geiger-Muller based detectors (in short: not a semiconductor but lamp based devices), I think it’s a cool idea to take a look at this approach.
In this post I will present such home-made sensor and a set of software to parse collected results.
It is a common thing to boot a Linux system (see the Raspberry Pi) from a micro SD card. It is not that common for a microcontroller. The NXP i.MX RT ARM Cortex-M7 fills that gap between these two worlds. No surprise that it features a ROM bootloader which can boot from a micro SD card.
Booting from a SD card is kind of cool: load a new software to the card, insert it and boot from it. In some applications this can be very useful: in my configuration the processor starts the ROM bootloader, then loads the image from the SD card into RAM and then runs it. In that configuration no internal or external FLASH memory would be needed.
In previous blog posts, I have described how an FTDI USB device can be programmed in Python to access the SWD bus of an ARM microprocessor. This allows the internals of the CPU to be accessed, without disrupting the currently running program.
In this blog I take the process one step further, and add a graphical front-end, that shows the CPU activity in real time
Now I can wirelessly control any Arduino project with just some small adjustments at the receiver side. This transmitter can be also used as any commercial RC transmitter for controlling RC toys, cars, drones and so on. For that purpose it just needs a simple Arduino receiver which then generates the appropriate signals for controlling those commercial RC devices. I will explain how everything works in this video through few examples of controlling an Arduino robot car, controlling the Arduino Ant Robot from my previous video and controlling a brushless DC motor using an ESC and some servo motors.
In my previous post, I designed and 3D printed a high voltage connector for my Bertan 225-20R high voltage power supply. The silicone high voltage wire I ordered had finally arrived so I made a couple of cables using the connectors I printed. A few of my viewers had questioned the suitability of using PLA as printing material in high voltage applications so I decided to measure the dielectric breakdown voltage of PLA and gather some real-world data.