Henrik Ekblad
2fd948fc66
Upgraded RF24 to latest version which supports SoftSPI. Added DigitalIO and UTFT libraries to support the new example. Fix problem reported in RelayWithButtonActuator example.
79 lines
2.2 KiB
Arduino
79 lines
2.2 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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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) Serial.print("Read");
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if (rd && wr) Serial.print(" and ");
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if (wr) Serial.print("Write");
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Serial.println('.');
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}
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add += 2;
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}
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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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// Not used.
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}
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