Arduino IDE support for the University of Toronto Department of Physics student-workshop boards: a standalone Arduino core built directly on the Raspberry Pi pico-sdk. Install steps and the supported boards are on the home page; the pin map and board notes are on the Phyduino Pico page.

This reference covers the Arduino functions and what is different about them on Phyduino boards, plus what the Phyduino package adds. Other parts of the Arduino API (String, Serial.print(), isDigit(), ...) work as described in the Arduino language reference.

Arduino functions

Topic	Functions
Digital I/O	pinMode(), digitalWrite(), digitalRead()
Analog I/O	analogRead(), analogWrite(), analogReference(), resolution and PWM frequency; on every analog pin: averaging, millivolts, differential, several pins at once, fixed-rate bursts
Advanced I/O	tone(), noTone(), pulseIn(), pulseInLong(), shiftOut(), shiftIn()
Time	millis(), micros(), delay(), delayMicroseconds()
Interrupts	attachInterrupt(), attachInterruptParam(), detachInterrupt(), digitalPinToInterrupt(), interrupts(), noInterrupts()
Math	min(), max(), constrain(), map(), sq(), radians(), degrees(), PI, HALF_PI, TWO_PI, DEG_TO_RAD, RAD_TO_DEG, EULER
Random numbers	random(), randomSeed()
Bits and bytes	bit(), bitRead(), bitWrite(), bitSet(), bitClear(), bitToggle(), lowByte(), highByte(), makeWord(), word()
Sketch structure	setup(), loop(), yield(); start-up: init(), initVariant()
Multicore	setup1(), loop1(); rp2040: rp2040.fifo (push(), push_nb(), pop(), pop_nb(), available()), idleOtherCore(), resumeOtherCore(), restartCore1(), cpuid(), f_cpu(), getTotalHeap(), getUsedHeap(), getFreeHeap()
FreeRTOS	Tools > Operating System > FreeRTOS (SMP): the FreeRTOS kernel (tasks, queues, semaphores, mutexes, event groups, software timers, stream and message buffers); its settings, and what changes in delay() and yield()
CMSIS-RTOS2	Tools > Operating System > FreeRTOS (SMP) + CMSIS-RTOS2: ARM's CMSIS-RTOS2 API on FreeRTOS (threads, thread flags, timers, event flags, mutexes, semaphores, memory pools, message queues); how it differs from other systems, the functions provided and those not provided
Constants and types	HIGH, LOW, CHANGE, FALLING, RISING (PinStatus); INPUT, OUTPUT, INPUT_PULLUP, INPUT_PULLDOWN, OUTPUT_OPENDRAIN (PinMode); LSBFIRST, MSBFIRST (BitOrder); boolean, byte, word, pin_size_t, voidFuncPtr, voidFuncPtrParam

Phyduino additions

Topic	Use	Header
USB serial	Serial (SerialUSBClass)	SerialUSB.h
Hardware serial	Serial1 on D0/D1, Serial2 on D4/D5 (SerialUARTClass)	SerialUART.h
Multicore	setup1(), loop1(), rp2040 (RP2040Class, with rp2040.fifo, RP2040FifoClass)	RP2040.h
FreeRTOS	With Tools > Operating System > FreeRTOS (SMP): the FreeRTOS kernel	FreeRTOS.h, then task.h, queue.h, semphr.h, event_groups.h, timers.h, stream_buffer.h, message_buffer.h
CMSIS-RTOS2	With Tools > Operating System > FreeRTOS (SMP) + CMSIS-RTOS2: ARM's CMSIS-RTOS2 API	cmsis_os2.h
Analog and PWM extras	analogReadResolution(), analogReadAveraging(), analogReadMillivolts(), analogFullScaleMillivolts(), analogReadDifferentialMillivolts(), analogReadMultiple(), analogReadBurst(), analogStartBurst(), analogBurstDone(), analogStopBurst(), analogWriteResolution(), analogWriteFrequency()	Arduino.h
pico-sdk access	digitalPinToGpio(): the RP2040 GPIO behind an Arduino pin	Arduino.h
Pin map	A0-A5, LED_BUILTIN, SS, MOSI, MISO, SCK, SDA, SCL	pins_arduino.h
SPI	SPI (PhyduinoSPI): SCK D13, MOSI D11, MISO D12	SPI.h
I2C	Wire (PhyduinoWire): controller or peripheral on SDA/SCL	Wire.h
External ADC	max11635: the chip behind A3-A5, by channel (scan, true differential, bursts); sketches normally use the analog functions above	max11635.h
USB-PD power	stusb4500: sink profiles and the current contract	stusb4500.h

None of these need an #include except SPI.h, Wire.h, max11635.h, stusb4500.h, the FreeRTOS headers and cmsis_os2.h.

Examples

The Examples page lists the example sketches, also under File → Examples → Examples for Phyduino Pico in the Arduino IDE once Phyduino Pico is selected: Phyduino for the analog functions, USB-PD, the second core, FreeRTOS and CMSIS-RTOS2, SPI and Wire for those libraries.