LEAP#406 CH340G USB to Serial on a Breadboard
The CH340G is a USB to UART Interface chip. It is often used as a cheap alternative to more established brands. I have some CH340G chips, and with only a few extra components one can build a perfectly serviceable USB to TTL-level serial on a breadboard. I test it out by using it to program an ATmega328 on a breadboard over the serial link.
As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub
read more and comment..
mV Meter Battery and Protection Mod
The ATmega328-based millivolt meter based on a design by Scullcom Hobby Electronics has been serving well on my bench. But time for a couple of mods:
- adding a 9V internal battery that can be used when not connected to external supply - great for when the bench is crowded
- simple reverse-polarity protection (inline rectifier), particularly to avoid any confusion over centre-negative/centre-positive power connectors
As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub
read more and comment..
LEAP#405 Bootloaders and Arduino Serial Programming
The Arduino IDE makes programming AVR-based microcontrollers so easy that many quite simple concepts get lost in the fog. I confess to having been hazy for the longest time concerning the role of the bootloader and what exactly was going on when you click the “Upload Sketch” button. There are actually some great resources around the net and on YouTube, but they can also mislead a little because they might focus on just one aspect, so I decided to try and pull together a comprehensive soup-to-nuts story. It covers:
- How to check what bootloader (if any) is on a chip
- What bootloaders are available?
- How to burn a bootloader with the Arduino IDE
- How to burn a bootloader with Nick Gammon’s incredibly useful Arduino utility sketches
- Breadboard Setup for Programming over USB-Serial (FTDI and CH340 veriants)
- Programming over USB-Serial with the Arduino IDE
- Programming over USB-Serial with avrdude and gcc toolchain
As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub
read more and comment..
LEAP#404 The Arza-matron
I’ve had the other half of the guitar I used for The Fretboard (LEAP#018) sitting on a shelf ever since. It’s almost been thrown out a number of times, but luckily I didn’t as it proved to be inspiration for this last-minute idea for a party decoration.
The basic idea, using as many on-hand parts as possible:
- sound input
- 2 LED strip circuits independently controlled and powered from 12V
- simple Arduino sketch to sample the sound and drive the LED strips with PWM
It worked just fine, although in the process I discovered the sound module I used did not output continuous reading but rather a threshold trigger (so the effect was not as subtle as I planned). Something to fix next time I want to fire this up…
As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub
read more and comment..