The 8-bit ATtiny began life back in 1999 and has grown strong in the maker and engineering communities for nearly 20 years since its creation. The tiny microcontroller has been utilized for a myriad of exciting projects that range from IoT devices to robotics and everything in between. In this roundup, we will take a look at community hobbyist Stefan Wagner (wagiminator) has accomplished using several different variants of the ATtiny, with each having their own walkthrough.
The TinyUPS does what its name suggests — it’s an uninterruptible 5V/2.5A power supply that uses a rechargeable Li-ion battery as a buffer, and a load sharing power path management system. It also can be utilized for monitoring power supply and battery charge levels, as well as a communication pathway for connected devices. The ATtiny13 spends most of its time in “sleep mode,” and uses a watchdog timer to wake every eight seconds. It does so when an external power source is present; otherwise, it switches over to battery power. If the input voltage level drops below a certain threshold, it tells any connected device to shut down safely.
The DFPlayer is a LiPo battery-powered MP3 player that utilizes DFRobot’s DFPlayer module for playing songs written on a micro SD card. The player features a battery charging and protection circuit, battery level detection, and an OLED display to show song metrics, volume level, and battery charge percentage. It packs an on/off switch, volume control, status LEDs, and three push buttons to control the player. Users can also connect a 3.7V LiPo battery and a 3W/4Ohm speaker to the board for playing music on the go.
The TinyHVSP is a standalone high-voltage serial programmer and fuse resetter for ATtiny13/25/45/85 microcontrollers. The TinyHVSP features an ATtiny84A-SSU microcontroller, SMD tactile switch, MT3608 Step-Up DC/DC boost converter, and an ICSP-6 six-pin header for connecting microcontrollers. It also sports a USB connector, OLED display, and status LEDs for easy readouts.
The TinyLoad is described as a simple electronic dummy load, which measures voltage, current, and temperature of the connected heatsink. It calculates power, energy, and battery capacity, as well as controlling the fan, and posting the pertinent information on the equipped OLED display. The onboard button is used to switch between power/resistance and energy/capacity display. Wagner states the ADC of the ATtiny does its best to make the platform as accurate as possible, but it can be adjusted manually if needed.
The TinyDice is an electronic random die generator driven by an ATtiny13A-SSU microcontroller and features seven red LEDs to represent each face of the die. The digital dice also includes a pair of programmable toggle switches and is powered by a CR2032 coin cell battery.
The TinyFMRadio is another great project that makes use of the small microcontroller. Wagner designed his radio with RDS using an ATtiny85-20SU, an integrated audio amplifier, a rotary encoder, and an OLED display. It can even be directly connected to a Li-ion battery and 3W/4Ohm speaker for sharing music with others.
Wagner's TinyRemote is a simple but effective build for controlling projects. It’s outfitted with an ATtiny13A-SSU microcontroller, an IR333C/H0/L10 LED, IR333-A LED, six SMD tactile switches, and is powered by a CR2032 coin cell battery. It’s an excellent project for beginners who would like to practice their soldering skills.
The last entry in this roundup is another easy project for beginners looking to hone their PCB soldering skills. The TinyKnob is a rotary encoder with an integrated USB interface and V-USB software-only application of USB 1.1 devices on AVR. The included sample code implements volume control for PCs that works without drivers or acting as an HID device.
These are just a handful of boards Wagner created using the ATtiny along beginner, intermediate, and perhaps some advanced skill levels. Those interested in seeing more of his work can head over to his EasyEDA project page.