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-rw-r--r--libraries/Wire/Wire.cpp296
1 files changed, 109 insertions, 187 deletions
diff --git a/libraries/Wire/Wire.cpp b/libraries/Wire/Wire.cpp
index 8416525..9173234 100644
--- a/libraries/Wire/Wire.cpp
+++ b/libraries/Wire/Wire.cpp
@@ -25,236 +25,158 @@
*****************************************************************************/
/**
- * @brief Wire library, ported from Arduino. Provides a simplistic
- * interface to i2c.
+ * @file Wire.cpp
+ * @author Trystan Jones <crenn6977@gmail.com>
+ * @brief Wire library, uses the WireBase to create the primary interface
+ * while keeping low level interactions invisible to the user.
+ */
+
+/*
+ * Library updated by crenn to follow new Wire system.
+ * Code was derived from the original Wire for maple code by leaflabs and the
+ * modifications by gke and ala42.
*/
#include "Wire.h"
+#define I2C_WRITE 0
+#define I2C_READ 1
+
/* low level conventions:
* - SDA/SCL idle high (expected high)
* - always start with i2c_delay rather than end
*/
-uint32 i2c_delay = 1;
-void i2c_start(Port port) {
- I2C_DELAY;
- digitalWrite(port.sda,LOW);
- I2C_DELAY;
- digitalWrite(port.scl,LOW);
+void TwoWire::set_scl(bool state) {
+ I2C_DELAY(this->i2c_delay);
+ digitalWrite(this->scl_pin,state);
+ //Allow for clock stretching - dangerous currently
+ if (state == HIGH) {
+ while(digitalRead(this->scl_pin) == 0);
+ }
+}
+
+void TwoWire::set_sda(bool state) {
+ I2C_DELAY(this->i2c_delay);
+ digitalWrite(this->sda_pin, state);
}
-void i2c_stop(Port port) {
- I2C_DELAY;
- digitalWrite(port.scl,HIGH);
- I2C_DELAY;
- digitalWrite(port.sda,HIGH);
+void TwoWire::i2c_start() {
+ set_sda(LOW);
+ set_scl(LOW);
}
-boolean i2c_get_ack(Port port) {
- I2C_DELAY;
- digitalWrite(port.scl,LOW);
- I2C_DELAY;
- digitalWrite(port.sda,HIGH);
- I2C_DELAY;
- digitalWrite(port.scl,HIGH);
- I2C_DELAY;
+void TwoWire::i2c_stop() {
+ set_sda(LOW);
+ set_scl(HIGH);
+ set_sda(HIGH);
+}
- if (!digitalRead(port.sda)) {
- I2C_DELAY;
- digitalWrite(port.scl,LOW);
- return true;
- } else {
- I2C_DELAY;
- digitalWrite(port.scl,LOW);
- return false;
- }
+bool TwoWire::i2c_get_ack() {
+ set_scl(LOW);
+ set_sda(HIGH);
+ set_scl(HIGH);
+
+ bool ret = !digitalRead(this->sda_pin);
+ set_scl(LOW);
+ return ret;
}
-void i2c_send_ack(Port port) {
- I2C_DELAY;
- digitalWrite(port.sda,LOW);
- I2C_DELAY;
- digitalWrite(port.scl,HIGH);
- I2C_DELAY;
- digitalWrite(port.scl,LOW);
+void TwoWire::i2c_send_ack() {
+ set_sda(LOW);
+ set_scl(HIGH);
+ set_scl(LOW);
}
-void i2c_send_nack(Port port) {
- I2C_DELAY;
- digitalWrite(port.sda,HIGH);
- I2C_DELAY;
- digitalWrite(port.scl,HIGH);
+void TwoWire::i2c_send_nack() {
+ set_sda(HIGH);
+ set_scl(HIGH);
+ set_scl(LOW);
}
-uint8 i2c_shift_in(Port port) {
+uint8 TwoWire::i2c_shift_in() {
uint8 data = 0;
+ set_sda(HIGH);
int i;
- for (i=0;i<8;i++) {
- I2C_DELAY;
- digitalWrite(port.scl,HIGH);
- I2C_DELAY;
- data += digitalRead(port.sda) << (7-i);
- I2C_DELAY;
- digitalWrite(port.scl,LOW);
+ for (i = 0; i < 8; i++) {
+ set_scl(HIGH);
+ data |= digitalRead(this->sda_pin) << (7-i);
+ set_scl(LOW);
}
return data;
}
-void i2c_shift_out(Port port, uint8 val) {
+void TwoWire::i2c_shift_out(uint8 val) {
int i;
- for (i=0;i<8;i++) {
- I2C_DELAY;
- digitalWrite(port.sda, !!(val & (1 << (7 - i))));
- I2C_DELAY;
- digitalWrite(port.scl, HIGH);
- I2C_DELAY;
- digitalWrite(port.scl, LOW);
+ for (i = 0; i < 8; i++) {
+ set_sda(!!(val & (1 << (7 - i)) ) );
+ set_scl(HIGH);
+ set_scl(LOW);
}
}
-TwoWire::TwoWire() {
- i2c_delay = 0;
- rx_buf_idx = 0;
- rx_buf_len = 0;
- tx_addr = 0;
- tx_buf_idx = 0;
- tx_buf_overflow = false;
-}
-
-/*
- * Sets pins SDA and SCL to OUPTUT_OPEN_DRAIN, joining I2C bus as
- * master. If you want them to be some other pins, use begin(uint8,
- * uint8);
- */
-void TwoWire::begin() {
- begin(SDA, SCL);
-}
+uint8 TwoWire::process() {
+ itc_msg.xferred = 0;
-/*
- * Joins I2C bus as master on given SDA and SCL pins.
- */
-void TwoWire::begin(uint8 sda, uint8 scl) {
- port.sda = sda;
- port.scl = scl;
- pinMode(scl, OUTPUT_OPEN_DRAIN);
- pinMode(sda, OUTPUT_OPEN_DRAIN);
- digitalWrite(scl, HIGH);
- digitalWrite(sda, HIGH);
-}
-
-void TwoWire::beginTransmission(uint8 slave_address) {
- tx_addr = slave_address;
- tx_buf_idx = 0;
- tx_buf_overflow = false;
- rx_buf_idx = 0;
- rx_buf_len = 0;
-}
-
-void TwoWire::beginTransmission(int slave_address) {
- beginTransmission((uint8)slave_address);
-}
-
-uint8 TwoWire::endTransmission(void) {
- if (tx_buf_overflow) return EDATA;
-
- i2c_start(port);
-
- i2c_shift_out(port, (tx_addr << 1) | I2C_WRITE);
- if (!i2c_get_ack(port)) return ENACKADDR;
-
- // shift out the address we're transmitting to
- for (uint8 i = 0; i < tx_buf_idx; i++) {
- uint8 ret = writeOneByte(tx_buf[i]);
- if (ret) return ret; // SUCCESS is 0
+ uint8 sla_addr = (itc_msg.addr << 1);
+ if (itc_msg.flags == I2C_MSG_READ) {
+ sla_addr |= I2C_READ;
}
-
- i2c_stop(port);
-
- tx_buf_idx = 0;
- tx_buf_overflow = false;
- return SUCCESS;
-}
-
-uint8 TwoWire::requestFrom(uint8 address, int num_bytes) {
- if (num_bytes > WIRE_BUFSIZ) num_bytes = WIRE_BUFSIZ;
-
- rx_buf_idx = 0;
- rx_buf_len = 0;
- while (rx_buf_len < num_bytes) {
- if(!readOneByte(address, rx_buf + rx_buf_len)) rx_buf_len++;
- else break;
+ i2c_start();
+ // shift out the address we're transmitting to
+ i2c_shift_out(sla_addr);
+ if (!i2c_get_ack()) {
+ return ENACKADDR;
}
- return rx_buf_len;
-}
-
-uint8 TwoWire::requestFrom(int address, int numBytes) {
- return TwoWire::requestFrom((uint8)address, (uint8) numBytes);
-}
-
-void TwoWire::send(uint8 value) {
- if (tx_buf_idx == WIRE_BUFSIZ) {
- tx_buf_overflow = true;
- return;
+ // Recieving
+ if (itc_msg.flags == I2C_MSG_READ) {
+ while (itc_msg.xferred < itc_msg.length) {
+ itc_msg.data[itc_msg.xferred++] = i2c_shift_in();
+ if (itc_msg.xferred < itc_msg.length) {
+ i2c_send_ack();
+ } else {
+ i2c_send_nack();
+ }
+ }
}
-
- tx_buf[tx_buf_idx++] = value;
-}
-
-void TwoWire::send(uint8* buf, int len) {
- for (uint8 i = 0; i < len; i++) send(buf[i]);
-}
-
-void TwoWire::send(int value) {
- send((uint8)value);
-}
-
-void TwoWire::send(int* buf, int len) {
- send((uint8*)buf, (uint8)len);
-}
-
-void TwoWire::send(char* buf) {
- uint8 *ptr = (uint8*)buf;
- while(*ptr) {
- send(*ptr);
- ptr++;
+ // Sending
+ else {
+ for (uint8 i = 0; i < itc_msg.length; i++) {
+ i2c_shift_out(itc_msg.data[i]);
+ if (!i2c_get_ack()) {
+ return ENACKTRNS;
+ }
+ itc_msg.xferred++;
+ }
}
+ i2c_stop();
+ return SUCCESS;
}
-uint8 TwoWire::available() {
- return rx_buf_len - rx_buf_idx;
-}
-
-uint8 TwoWire::receive() {
- if (rx_buf_idx == rx_buf_len) return 0;
- return rx_buf[rx_buf_idx++];
+// TODO: Add in Error Handling if pins is out of range for other Maples
+// TODO: Make delays more capable
+TwoWire::TwoWire(uint8 scl, uint8 sda, uint8 delay) : i2c_delay(delay) {
+ this->scl_pin=scl;
+ this->sda_pin=sda;
}
-// private methods
-
-uint8 TwoWire::writeOneByte(uint8 byte) {
- i2c_shift_out(port, byte);
- if (!i2c_get_ack(port)) return ENACKTRNS;
-
- return SUCCESS;
+void TwoWire::begin(uint8 self_addr) {
+ tx_buf_idx = 0;
+ tx_buf_overflow = false;
+ rx_buf_idx = 0;
+ rx_buf_len = 0;
+ pinMode(this->scl_pin, OUTPUT_OPEN_DRAIN);
+ pinMode(this->sda_pin, OUTPUT_OPEN_DRAIN);
+ set_scl(HIGH);
+ set_sda(HIGH);
}
-uint8 TwoWire::readOneByte(uint8 address, uint8 *byte) {
- i2c_start(port);
-
- i2c_shift_out(port, (address << 1) | I2C_READ);
- if (!i2c_get_ack(port)) return ENACKADDR;
-
- *byte = i2c_shift_in(port);
-
- i2c_send_nack(port);
- i2c_stop(port);
-
- return SUCCESS; // no real way of knowing, but be optimistic!
+TwoWire::~TwoWire() {
+ this->scl_pin=0;
+ this->sda_pin=0;
}
// Declare the instance that the users of the library can use
-TwoWire Wire;
-
+TwoWire Wire(); \ No newline at end of file
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-21 19:32:57 +0000