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ferris/0_1: update I2C API usage (#24839)
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@fauxpark
fauxpark authored Jan 20, 2025
1 parent a98070f commit 68130cc
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Showing 3 changed files with 21 additions and 30 deletions.
45 changes: 20 additions & 25 deletions keyboards/ferris/0_1/matrix.c
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Original file line number Diff line number Diff line change
Expand Up @@ -29,7 +29,7 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
#include "i2c_master.h"

extern i2c_status_t mcp23017_status;
#define I2C_TIMEOUT 1000
#define MCP23017_I2C_TIMEOUT 1000

// For a better understanding of the i2c protocol, this is a good read:
// https://www.robot-electronics.co.uk/i2c-tutorial
Expand All @@ -41,33 +41,31 @@ extern i2c_status_t mcp23017_status;
// All address pins of the mcp23017 are connected to the ground on the ferris
// | 0 | 1 | 0 | 0 | A2 | A1 | A0 |
// | 0 | 1 | 0 | 0 | 0 | 0 | 0 |
#define I2C_ADDR 0b0100000
#define I2C_ADDR_WRITE ((I2C_ADDR << 1) | I2C_WRITE)
#define I2C_ADDR_READ ((I2C_ADDR << 1) | I2C_READ)
#define I2C_ADDR (0b0100000 << 1)

// Register addresses
// See https://github.com/adafruit/Adafruit-MCP23017-Arduino-Library/blob/master/Adafruit_MCP23017.h
#define IODIRA 0x00 // i/o direction register
#define IODIRB 0x01
#define GPPUA 0x0C // GPIO pull-up resistor register
#define GPPUB 0x0D
#define GPIOA 0x12 // general purpose i/o port register (write modifies OLAT)
#define GPIOB 0x13
#define MCP23017_GPIOA 0x12 // general purpose i/o port register (write modifies OLAT)
#define MCP23017_GPIOB 0x13
#define OLATA 0x14 // output latch register
#define OLATB 0x15

bool i2c_initialized = 0;
i2c_status_t mcp23017_status = I2C_ADDR;

uint8_t init_mcp23017(void) {
print("starting init");
print("init mcp23017\n");
mcp23017_status = I2C_ADDR;

// I2C subsystem
if (i2c_initialized == 0) {
i2c_init(); // on pins D(1,0)
i2c_initialized = true;
wait_ms(I2C_TIMEOUT);
wait_ms(MCP23017_I2C_TIMEOUT);
}

// set pin direction
Expand All @@ -76,17 +74,19 @@ uint8_t init_mcp23017(void) {
// - driving : output : 0
// This means: we will read all the bits on GPIOA
// This means: we will write to the pins 0-4 on GPIOB (in select_rows)
uint8_t buf[] = {IODIRA, 0b11111111, 0b11110000};
mcp23017_status = i2c_transmit(I2C_ADDR_WRITE, buf, sizeof(buf), I2C_TIMEOUT);
uint8_t buf[] = {0b11111111, 0b11110000};
print("before transmit\n");
mcp23017_status = i2c_write_register(I2C_ADDR, IODIRA, buf, sizeof(buf), MCP23017_I2C_TIMEOUT);
uprintf("after transmit %i\n", mcp23017_status);
if (!mcp23017_status) {
// set pull-up
// - unused : on : 1
// - input : on : 1
// - driving : off : 0
// This means: we will read all the bits on GPIOA
// This means: we will write to the pins 0-4 on GPIOB (in select_rows)
uint8_t pullup_buf[] = {GPPUA, 0b11111111, 0b11110000};
mcp23017_status = i2c_transmit(I2C_ADDR_WRITE, pullup_buf, sizeof(pullup_buf), I2C_TIMEOUT);
mcp23017_status = i2c_write_register(I2C_ADDR, GPPUA, buf, sizeof(buf), MCP23017_I2C_TIMEOUT);
uprintf("after transmit2 %i\n", mcp23017_status);
}
return mcp23017_status;
}
Expand Down Expand Up @@ -144,12 +144,12 @@ bool matrix_scan_custom(matrix_row_t current_matrix[]) {
// if (++mcp23017_reset_loop >= 1300) {
// since mcp23017_reset_loop is 8 bit - we'll try to reset once in 255 matrix scans
// this will be approx bit more frequent than once per second
dprint("trying to reset mcp23017\n");
print("trying to reset mcp23017\n");
mcp23017_status = init_mcp23017();
if (mcp23017_status) {
dprint("right side not responding\n");
print("right side not responding\n");
} else {
dprint("right side attached\n");
print("right side attached\n");
}
}
}
Expand Down Expand Up @@ -204,18 +204,13 @@ static matrix_row_t read_cols(uint8_t row) {
if (mcp23017_status) { // if there was an error
return 0;
} else {
uint8_t buf[] = {GPIOA};
mcp23017_status = i2c_transmit(I2C_ADDR_WRITE, buf, sizeof(buf), I2C_TIMEOUT);
// We read all the pins on GPIOA.
// The initial state was all ones and any depressed key at a given column for the currently selected row will have its bit flipped to zero.
// The return value is a row as represented in the generic matrix code were the rightmost bits represent the lower columns and zeroes represent non-depressed keys while ones represent depressed keys.
// Since the pins connected to eact columns are sequential, and counting from zero up (col 5 -> GPIOA0, col 6 -> GPIOA1 and so on), the only transformation needed is a bitwise not to swap all zeroes and ones.
uint8_t data[] = {0};
if (!mcp23017_status) {
mcp23017_status = i2c_receive(I2C_ADDR_READ, data, sizeof(data), I2C_TIMEOUT);
data[0] = ~(data[0]);
}
return data[0];
mcp23017_status = i2c_read_register(I2C_ADDR, MCP23017_GPIOA, data, sizeof(data), MCP23017_I2C_TIMEOUT);
return ~data[0];
}
}
}
Expand All @@ -236,7 +231,7 @@ static void unselect_rows(void) {

static void select_row(uint8_t row) {
if (row < MATRIX_ROWS_PER_SIDE) {
// select on atmega32u4
// select on MCU
pin_t matrix_row_pins_mcu[MATRIX_ROWS_PER_SIDE] = MATRIX_ROW_PINS_MCU;
pin_t pin = matrix_row_pins_mcu[row];
gpio_set_pin_output(pin);
Expand All @@ -248,8 +243,8 @@ static void select_row(uint8_t row) {
} else {
// Select the desired row by writing a byte for the entire GPIOB bus where only the bit representing the row we want to select is a zero (write instruction) and every other bit is a one.
// Note that the row - MATRIX_ROWS_PER_SIDE reflects the fact that being on the right hand, the columns are numbered from MATRIX_ROWS_PER_SIDE to MATRIX_ROWS, but the pins we want to write to are indexed from zero up on the GPIOB bus.
uint8_t buf[] = {GPIOB, 0xFF & ~(1 << (row - MATRIX_ROWS_PER_SIDE))};
mcp23017_status = i2c_transmit(I2C_ADDR_WRITE, buf, sizeof(buf), I2C_TIMEOUT);
uint8_t buf[] = {0xFF & ~(1 << (row - MATRIX_ROWS_PER_SIDE))};
mcp23017_status = i2c_write_register(I2C_ADDR, MCP23017_GPIOB, buf, sizeof(buf), MCP23017_I2C_TIMEOUT);
}
}
}
3 changes: 1 addition & 2 deletions keyboards/ferris/0_2/matrix.c
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Original file line number Diff line number Diff line change
Expand Up @@ -30,8 +30,7 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.

extern i2c_status_t mcp23017_status;
#define MCP23017_I2C_TIMEOUT 1000
#define I2C_WRITE 0x00
#define I2C_READ 0x01

// For a better understanding of the i2c protocol, this is a good read:
// https://www.robot-electronics.co.uk/i2c-tutorial

Expand Down
3 changes: 0 additions & 3 deletions platforms/avr/drivers/i2c_master.h
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Original file line number Diff line number Diff line change
Expand Up @@ -21,9 +21,6 @@

#include <stdint.h>

#define I2C_READ 0x01
#define I2C_WRITE 0x00

typedef int16_t i2c_status_t;

#define I2C_STATUS_SUCCESS (0)
Expand Down

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