Patrick Fallberg
8e1ef13804
The rules are in .tools/astyle/config/style.cfg and can also be reviewed at https://www.mysensors.org/view/260#coding-guidelines-core-library
86 lines
2.1 KiB
Arduino
86 lines
2.1 KiB
Arduino
/* Scan I2C bus for devices.
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*
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* For I2C write addresses: the scanner sends a start,
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* the write address, looks for an ACK, then sends a stop.
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*
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* For I2C read addresses: the scanner sends a start, the
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* read address, looks for an ACK. If there is an ACK, it
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* reads a byte and NACKs it. Finally it sends a stop.
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*
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* When the I2C chip responds to the read address, it
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* outputs data and will miss a stop condition sent
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* immediately after the read address (bus contention).
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*
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* If the I2C chip misses the stop condition, the
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* address scanner will see ghost addresses until the
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* read ends randomly. By reading a byte after any read
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* address that ACKs, there is a chance to NACK the read
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* and properly end the I2C transaction.
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*/
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#include <DigitalIO.h>
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// Set pin numbers for your configuration.
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const uint8_t SDA_PIN = A4;
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const uint8_t SCL_PIN = A5;
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SoftI2cMaster i2c(SCL_PIN, SDA_PIN);
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//FastI2cMaster<SCL_PIN, SDA_PIN> i2c;
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//------------------------------------------------------------------------------
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void setup()
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{
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Serial.begin(9600);
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while (!Serial);
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if (!digitalRead(SDA_PIN) && !digitalRead(SCL_PIN)) {
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Serial.println("External pull-up resistors appear to be missing.");
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Serial.println("Many false responses may be detected.");
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Serial.println("Type any character to continue.");
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while (!Serial.available());
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Serial.println();
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}
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uint8_t add = 0;
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bool found = false;
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do {
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bool wr = i2c.transfer(add | I2C_WRITE, 0, 0);
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bool rd = i2c.transfer(add | I2C_READ, 0, 0, I2C_CONTINUE);
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if (rd) {
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uint8_t dummy;
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// Must read byte, send NACK, and issue STOP.
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i2c.transferContinue(&dummy, 1);
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}
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if (rd || wr) {
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found = true;
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Serial.print("Device at address: 0X");
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Serial.print(add, HEX);
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Serial.print(" responds to ");
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if (rd) {
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Serial.print("Read");
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}
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if (rd && wr) {
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Serial.print(" and ");
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}
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if (wr) {
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Serial.print("Write");
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}
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Serial.println('.');
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}
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add += 2;
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} while (add);
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if (!found) {
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Serial.println("No devices found.");
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}
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Serial.println("Done");
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}
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//------------------------------------------------------------------------------
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void loop()
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{
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// Not used.
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}
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