pilotak / ds248x Goto Github PK

The waitBusy() function seems to be generating quite a bit of delay, to the point where it takes about a minute to discover 6 DS18B20s on a bus. I added the following debug to the waitBusy() function:

while ((buf[0] & DS248X_STATUS_1WB) && ((poll_count++) < DS248X_POLL_LIMIT))
{
_timer = GetMicroseconds();
_i2c->read(_address, buf, 1, buf[0] & DS248X_STATUS_1WB);
_timer = GetMicroseconds() - _timer;
tr_debug("wait time: %dus", _timer);
}

and I get the following kind of output during a search:

[DBG ][WIRE]: Sending[2]: 78:00
[DBG ][WIRE]: wait time: 150400us
[DBG ][WIRE]: wait time: 86us
[DBG ][WIRE]: Sending[2]: 78:00
[DBG ][WIRE]: wait time: 150381us
[DBG ][WIRE]: wait time: 109us
[DBG ][WIRE]: Sending[2]: 78:00
[DBG ][WIRE]: wait time: 150403us
[DBG ][WIRE]: wait time: 86us
[DBG ][WIRE]: Sending[2]: 78:00
[DBG ][WIRE]: wait time: 150381us
[DBG ][WIRE]: wait time: 112us
[DBG ][WIRE]: Sending[2]: 78:00
[DBG ][WIRE]: wait time: 150403us
[DBG ][WIRE]: wait time: 112us
[DBG ][WIRE]: Sending[2]: 78:00
[DBG ][WIRE]: wait time: 150380us
[DBG ][WIRE]: wait time: 108us
[DBG ][WIRE]: Sending[2]: 78:00
[DBG ][WIRE]: wait time: 150404us
[DBG ][WIRE]: wait time: 109us
[DBG ][WIRE]: Sending[2]: 78:00
[DBG ][WIRE]: wait time: 150378us
[DBG ][WIRE]: wait time: 108us

It appears there are I2C reads taking over 150ms, which is quite long. I am running this on an STM32F103RB MCU. Why might this be taking so long?