Datasheet

142 pio_i2c_resume_after_error(pio, sm);
143 pio_i2c_stop(pio, sm);
144 }
Pico Examples: https://github.com/raspberrypi/pico-examples/tree/master/pio/i2c/pio_i2c.c Lines 19 - 23
19 void pio_i2c_resume_after_error(PIO pio, uint sm) {
20 pio_sm_drain_tx_fifo(pio, sm);
21 pio_sm_exec(pio, sm, (pio->sm[sm].execctrl & PIO_SM0_EXECCTRL_WRAP_BOTTOM_BITS) >>
Ê PIO_SM0_EXECCTRL_WRAP_BOTTOM_LSB);
22 pio->irq = 1u << sm;
23 }
We need some higher-level functions to pass correctly-formatted data though the FIFOs and insert Starts, Stops, NAKs
and so on at the correct points. This is enough to present a similar interface to the other hardware I2Cs on RP2040.
Pico Examples: https://github.com/raspberrypi/pico-examples/tree/master/pio/i2c/i2c_bus_scan.c Lines 13 - 42
13 int main() {
14 stdio_init_all();
15
16 PIO pio = pio0;
17 uint sm = 0;
18 uint offset = pio_add_program(pio, &i2c_program);
19 i2c_program_init(pio, sm, offset, PIN_SDA, PIN_SCL);
20
21 printf("\nPIO I2C Bus Scan\n");
22 printf(" 0 1 2 3 4 5 6 7 8 9 A B C D E F\n");
23
24 for (int addr = 0; addr < (1 << 7); ++addr) {
25 if (addr % 16 == 0) {
26 printf("%02x ", addr);
27 }
28 // Perform a 0-byte read from the probe address. The read function
29 // returns a negative result NAK'd any time other than the last data
30 // byte. Skip over reserved addresses.
31 int result;
32 if (reserved_addr(addr))
33 result = -1;
34 else
35 result = pio_i2c_read_blocking(pio, sm, addr, NULL, 0);
36
37 printf(result < 0 ? "." : "@");
38 printf(addr % 16 == 15 ? "\n" : " ");
39 }
40 printf("Done.\n");
41 return 0;
42 }
3.6.8. PWM
RP2040 Datasheet
3.6. Examples 383