Arduino Pro Mini simulator, at 5 V and at 3.3 V
The Pro Mini is the Uno’s ATmega328P on the smallest Arduino there is, with no USB on it. Mokxi has both builds: 5 V at 16 MHz, which runs the Nano’s programs, and 3.3 V at 8 MHz, where every pin, the pull-ups and the ADC’s full scale are 3.3 V and every clock cycle takes twice as long.
- 6peripheral areas modeled
- 2projects ready to run
- Real timeon your own machine
What is modeled
Taken from the board's own contract document and put in plain words, with what is missing beside it.
Modeled
- Core
- Every ATmega328P mnemonic with datasheet cycle counts, at 16 MHz or 8 MHz
- Timers
- Three, in every waveform mode, counting at the board’s own clock
- USART0
- Wired to the serial monitor, with the baud divisor worked out from the board’s clock
- ADC
- Eight channels against AVCC, which is the board’s own supply: A0 to A3 on the rows, A4 to A7 inside the board
- Supply
- 5 V or 3.3 V on VCC, the pins, the pull-ups and RESET
- The board
- The 33 by 18 mm outline, two rows 0.6 inch apart, RESET at both ends on one trace
Not modeled
- The FTDI header and a USB-serial adapter on it. Serial reaches the monitor directly, and there is no DTR to reset the board.
- The regulator: RAW is ignored and VCC is an ideal rail.
- The ATmega168 builds of the board.
Open one and press Run
Each of these opens in the editor exactly as it is drawn here.
Every built-in project on the Pro Mini
Each has its own page with the circuit running, the code and a parts list.
Arduino libraries that compile as they are
Paste a tutorial that includes one of these and it builds. For any other library, the build names the Mokxi header that does the same job.
And 15 more, 23 in all: OneWire.h and DallasTemperature.h; Adafruit_BME280.h, Adafruit_BMP280.h and SparkFunBME280.h; RTClib.h; Adafruit_SHT31.h; Adafruit_PCF8591.h; Adafruit_ADXL345_U.h; LedControl.h; Adafruit_LEDBackpack.h; Adafruit_TCS34725.h; Adafruit_SGP30.h; Adafruit_INA219.h; Adafruit_ADS1X15.h; Adafruit_MCP23X17.h; Bounce2.h; HX711.h.
Tutorials that use this board
Each one ends in a running circuit, on this same board.
Questions
Is it free?
Yes. Every board and every part is on the free plan, with no account needed.
Why does my sketch run at half speed on the 3.3 V board?
Because it was built for 16 MHz and the 3.3 V board runs at 8 MHz, which is what a real one does when the IDE’s board menu is set wrong. Sketches you compile for the 3.3 V board here are built for 8 MHz and keep time.
Where are A4 to A7?
Four holes inside the board. Here they sit on its center line, over the breadboard’s channel, so reach them with a jumper. A6 and A7 are analog inputs and nothing else, as on the Nano.
Will a Nano sketch run on it?
On the 5 V board, unchanged: the same chip, the same clock and the same image. On the 3.3 V board, compile it again for 8 MHz.
The other boards
Every one of these runs today, and every one is free.
Every Arduino board in one place: the Arduino simulator.
A RISC-V chip at 160 MHz, on the real memory map.
The classic Arduino, with an ATmega328P running at 16 MHz.
The Uno’s chip on a small board that fits a breadboard.
The big Arduino, with 54 digital pins and four serial ports.
An Uno-shaped board whose chip does its own USB serial.
A second RISC-V board, with 31 pins and simulated WiFi.
The classic ESP32 at 240 MHz, with simulated WiFi.
The ESP32-S3 at 240 MHz, with USB serial and an RGB LED.
Try it on your own firmware
What you build here runs on the board on your desk, unchanged. Nothing to install and no account needed.