Hamster Mix: Portable open source Bluetooth MIDI controller with Arduino and ESP32 (schematics, source code, etc.)

Hamster Mix is ​​a portable MIDI controller powered by Arduino that connects to MIDI via Bluetooth. It allows you to control effects and play MIDI notes in 5 octaves. Twelve keys and the ability to switch up and down through the octave make it easy to control the notes of an entire keyboard piano using our compact controller (about the size of a hamster). Hamster Mix connects to Mac, PC, Ipad and even mobile phones via Bluetooth. You can control any MIDI-enabled music program such as Ableton, Garage Band, FL Studio, Reaper, etc. Two additional buttons and two potentiometers allow you to set up your own custom effects. You can even use the buttons as a Bluetooth track launcher instead of a keyboard. You can control MIDI-enabled mobile applications such as GarageBand, FL Studio Mobile, Reason Compact, Audiokit Synth One, Moog applications, and more. Make music on the go with Hamster Mix, which fits in your pocket, meaning no wires or bulky equipment.

Schematic PCB

Maker LED Display: Arduino programmable and internet-connected LED matrix display

Maker LED displays make using LED matrix displays easy. The ready-to-use, fully assembled circuit board has everything you need to run your monitor - just plug it in! Using and customizing the display is easy, with a specially written Arduino library and a dozen pre-made examples. The Maker LED display also has Wi-Fi so it can connect to the Internet to retrieve and display information. Choose between 32 x 9 pixel or 64 x 9 pixel versions and select LED color: white, blue, red, green, orange or violet.

Schematic PCB

Real-time clock made by STC90C54RD+SD2405ALPI

I have an SD2405ALPI-G on hand, and I happen to have an STC learning board, so I made a clock with an annual error of about 2.5 minutes to play with. The schematic and program are all there. Now the hardware has a ringtone generating chip and a power amplifier chip, but the program has only initially implemented the function of displaying the day of the week, hours, minutes and seconds. It will be changed to an alarm clock when there is time.

Schematic PCB

esp32 TFT color screen projection

The color screen projection assistant uses the tcp protocol to send the computer screen to esp32 for processing and display in real time, with a theoretical frame rate of more than 10 frames

Schematic PCB

Electronic scale solution, schematic diagram and program based on AT89C51

Electronic scale solution, schematic diagram and program based on AT89C51

Schematic PCB

Electronic dice source program list (assembly language)

Electronic dice source program list

Schematic PCB

Infrared remote control Proteus simulation circuit transmitting and receiving program

Infrared remote control Proteus simulation circuit transmitting and receiving program

Schematic PCB

Electric vehicle charger source program based on ATmega48PA chip, including PCB board

The charger program written with STM8S003 has positive and negative pulses throughout the process, anti-reverse connection, scheduled shutdown during charging, and negative pulses to repair the battery later.

Schematic PCB

51 Make a perpetual calendar (schematic diagram, program)

51 Make a perpetual calendar (schematic diagram, program)

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51 microcontroller electronic keyboard design

Electronic keyboard design based on 51 microcontroller.

Schematic PCB

Open source audio amplifier

The power supply has a stable symmetrical +/- 40 V to ensure optimal performance.
Maximum power (THD 1%) approaches 100 W into 8 Ω load and 190 W into 4 Ω load (see measurements). All parts are through-hole, making it easy to build the amplifier. The design is completely symmetrical.

Schematic PCB

MSP430F149+1602 digital display and real-time clock

MSP430F149+1602 digital display and real-time clock

Schematic PCB

Single-chip wireless dual-display answering machine based on AT89S51 (with papers, circuit diagrams, and C language programs)

This design is a system built using AT98C51 microcontroller. The wireless answering terminal uses a combination of PT2262 transmit encoding chip + F05P transmit module (including thesis description, circuit diagram, and C program are complete)

Schematic PCB

Heart-shaped running water lamp program and circuit

Heart-shaped running water lamp program and circuit.

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Xiaomi gravity sensor remote control

Xiaomi gravity sensor remote control (contains schematic diagram, code)

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Intelligent non-contact infrared electronic thermometer with voice broadcast

The program is written in C language and contains MLX90614 temperature measurement, OLED driver, and 4004-8 voice chip driver. The entire system is user-friendly. The user can choose voice broadcast or OLED display, low temperature or over-temperature alarm, and forehead skin function. Conversion formula from temperature to real body temperature (the formula has been verified by actual measurements and has high accuracy). The entire system has been verified to be feasible, and the measurement results were compared with electronic thermometers on the market, with an accuracy higher than 98%.

Schematic PCB

PlainDAQ: Simple open source DAQ module for Raspberry Pi Pico (schematic, source code, etc.)

PlainDAQ is a simple, useful tool that adds basic precision analog functionality to your Raspberry Pi Pico board. It features a precision, low noise, low drift 12-bit 500k sps/s ADC. To match the ADC and maintain its noise and accuracy, all analog inputs are buffered and the ADC is driven by a high speed/low noise fully differential amplifier. It also has a 10-bit DAC that helps create analog outputs and waveforms.

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Light cube production source code + schematic diagram

Light cube production source code + schematic diagram.

Schematic PCB

Design program of password lock based on microcontroller

51 microcontroller password lock LCD display

Schematic PCB

Small quadcopter DIY

IAP15W4K58S4-Small quadcopter DIY

Schematic PCB