43 lines
1.1 KiB
C
43 lines
1.1 KiB
C
#include <stdio.h>
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#include "pico/stdlib.h"
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#include "pio_i2c.h"
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#define PIN_SDA 2
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#define PIN_SCL 3
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bool reserved_addr(uint8_t addr) {
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return (addr & 0x78) == 0 || (addr & 0x78) == 0x78;
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}
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int main() {
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stdio_init_all();
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PIO pio = pio0;
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uint sm = 0;
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uint offset = pio_add_program(pio, &i2c_program);
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i2c_program_init(pio, sm, offset, PIN_SDA, PIN_SCL);
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printf("\nPIO I2C Bus Scan\n");
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printf(" 0 1 2 3 4 5 6 7 8 9 A B C D E F\n");
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for (int addr = 0; addr < (1 << 7); ++addr) {
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if (addr % 16 == 0) {
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printf("%02x ", addr);
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}
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// Perform a 0-byte read from the probe address. The read function
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// returns a negative result NAK'd any time other than the last data
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// byte. Skip over reserved addresses.
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int result;
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if (reserved_addr(addr))
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result = -1;
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else
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result = pio_i2c_read_blocking(pio, sm, addr, NULL, 0);
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printf(result < 0 ? "." : "@");
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printf(addr % 16 == 15 ? "\n" : " ");
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}
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printf("Done.\n");
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return 0;
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}
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