// examples

51 demos. One peripheral each.

Every example is self-contained and builds to its own UF2, typically under 4 KB. They are reading material as much as code — each starts with an @ comment block explaining what's being exercised and what to expect on the wire.

Build any one with make build/<name>_flash.uf2 · full source on GitHub ↗.

// adc

1 demo

adc_temp_demo.S

147 loc

read on-die temperature sensor every ~500 ms.

// bootrom

1 demo

bootsel_usb_demo.S

141 loc

exercise rom_reset_to_bootsel.

// bring-up

1 demo

init_timing_demo.S

384 loc

measure where init time is spent.

// clocks

1 demo

clocks_demo.S

66 loc

end-to-end M2 clock-tree bring-up demo.

// dma

4 demos

dma_memcpy_demo.S

235 loc

DMA memory-to-memory throughput demo (M3-C).

dma_sniff_demo.S

140 loc

DMA sniffer / CRC32 demo (M3-C).

dma_uart_demo.S

107 loc

DMA-paced UART TX demo (M3-C).

dma_usb_demo.S

281 loc

DMA mem-to-mem verification via LED + USB CDC.

// diagnostics

1 demo

diag.S

160 loc

stage-blinker for bisecting the M2 boot hang on real silicon.

// gpio

3 demos

gpio_demo.S

130 loc

3-LED bar pattern across GPIO22/23/24.

gpio_irq_demo.S

100 loc

GPIO0 EDGE_LOW IRQ -> toggles on-board LED.

gpio_test_fixture.S

54 loc

test-only fixture that *references* every public gpio_* / gpio_qspi_* symbol so --gc-sections doesn't drop them.

// gpio / led

3 demos

blinky_buggy_demo.S

67 loc

slot B app for the TSBL-ab rollback demo.

blinky_confirmed_demo.S

69 loc

slot A app for the TSBL-ab rollback demo.

blinky_v01.S

63 loc

the v0.1 demo, preserved for regression testing.

// i²c

3 demos

i2c_eeprom_demo.S

215 loc

24LC256-style EEPROM write/read demo (M4-F).

i2c_master_slave_loopback_demo.S

301 loc

I2C0 master <-> I2C1 slave loop.

i2c_scan_demo.S

156 loc

7-bit I2C bus scan on I2C0 (SDA=GP4, SCL=GP5).

// linker / sram

1 demo

ramfunc_demo.S

230 loc

cycle-determinism: flash XIP vs SRAM (.ramfunc)

// mixed peripherals

1 demo

data_usb_demo.S

253 loc

ADC + TRNG + SHA256 verification via USB CDC.

// multicore

2 demos

multicore_full_usb_demo.S

266 loc

spinlock + mailbox + interp verification.

multicore_usb_demo.S

185 loc

dual-core verification via LED + USB CDC.

// otp

1 demo

otp_usb_demo.S

185 loc

read factory OTP rows + report via USB CDC.

// pio

2 demos

pio_blink_demo.S

111 loc

drive GP25 (LED) from PIO0 SM0 using a hand-encoded blink program. Demonstrates the M5-I controller API end-to-end.

pio_usb_demo.S

187 loc

PIO controller verification via LED + USB CDC.

// pwm

4 demos

pwm_fade_demo.S

137 loc

4-second triangle fade on GP25 (on-board LED, slice 4 ch B).

pwm_irq_demo.S

163 loc

slice 0 wrap IRQ toggles GP25 (on-board LED).

pwm_servo_demo.S

136 loc

50 Hz hobby-servo signal on GP15 (slice 7B).

pwm_usb_demo.S

209 loc

PWM fade verification via on-board LED + USB CDC.

// qmi / xip

1 demo

qmi_usb_demo.S

225 loc

measure XIP flash-read speed before/after QMI tuning.

// sha-256

1 demo

sha256_demo.S

99 loc

hash "abc" via the hardware SHA-256 engine and print result

// spi

3 demos

spi_dma_demo.S

199 loc

SPI0 + DMA full-duplex via internal loopback (M4-G).

spi_loopback_demo.S

162 loc

SPI0 internal loopback (M4-G).

spi_master_slave_loopback_demo.S

207 loc

Wire SPI0 (master) <-> SPI1 (slave) externally and ping a "PING" message.

// scheduler

3 demos

sched_demo.S

229 loc

NVIC-priority kernel demo, three soft tasks at three priorities

sched_usb_demo.S

253 loc

sched + spsc + sched_stats verification.

sched_watchdog_demo.S

191 loc

Setup: - Watchdog armed with a 200 ms timeout. - High-priority task T_FEED feeds the watchdog every 100 ms. - Medium-priority task T_HEARTBEAT prints "alive\r\n" every 1 s. - GP25 LED toggles inside T_FEED so you can see liveness.