Description
I have several I2C based libraries that therefor use the Wire library.
These are hard to test as there is minimal support in GODMODE.
One of the functions I would like to see supported is connection test from which I expect a time out in fact.
It does a sort of "Ping" over I2C and is code wise core in every I2C scanner.
Unfortunately it doesn't give the expected result.
Example snippet from - https://github.com/RobTillaart/MCP4725
bool MCP4725::isConnected()
{
Wire.beginTransmission(_deviceAddress);
return (Wire.endTransmission() == 0);
}Currently this function returns true currently in the unittest.
It should return false as the end transmission should get a NACK on transmission of the address.
// https://www.arduino.cc/en/Reference/WireEndTransmission
Furthermore it would be useful to be able to add a device ID in GODMODE I2C, something like
GodMode->Wire->add(deviceAddress);So that at least such basic ping could work.
A more elaborated Wire implementation could set and get register values so I could do something like
GodMode->Wire->add(deviceAddress);
GodMode->Wire->setRegister(1, 0xF5); // loads value F5 in a virtual register
n = WireRequestFrom(addr, 1); // pseudo
assertEqual(0xF5, n);
// and to check a written value
value = GodMode->Wire->getRegister(1); No priority as I am not blocked by it.
A small test program to see status when (not) connected.
// FILE: WireConnectionTest.ino
// AUTHOR: Rob Tillaart
// VERSION: 0.1.0
#include "Wire.h"
void setup()
{
Serial.begin(115200);
Serial.println("Wire connection test");
Wire.begin();
uint8_t addr = 0x62;
Wire.beginTransmission(addr);
int rv = Wire.endTransmission();
// https://www.arduino.cc/en/Reference/WireEndTransmission
Serial.print("ADDRESS:\t");
Serial.println(addr, HEX);
Serial.print("RETURNS:\t");
Serial.print(rv);
switch (rv)
{
case 0:
Serial.println("\tsuccess");
break;
case 1:
Serial.println("\tdata too long to fit in transmit buffer");
break;
case 2:
Serial.println("\treceived NACK on transmit of address"); // NOT CONNECTED, ADDRESS NOT FOUND
break;
case 3:
Serial.println("\treceived NACK on transmit of data");
break;
case 4:
default:
Serial.println("\tother error");
break;
}
}
void loop()
{
}
// -- END OF FILE --