We are using ADT7470 connected to 4 TMP05 sensors and 4 fans for fan speed control. The schematics is attached. It is observed that interrupts are issued by the ADT7470 that indicates crossing of the temperature thresholds at irregular intervals. And the interrupt is getting cleared within a second, itself. Why is the issuing such spurious interrupts? The device is configured to control the fan speed in automatic mode. The configuration made in the written driver is as follows:
1. In register 0x40= 0x00
18.0x44, 0x46, 0x48, 0x4A= 0xA
19.0x45, 0x47, 0x49, 0x4B= 0x50
20.0x58, 0x5A, 0x5C, 0x5E= 0x20
21.0x60, 0x62, 0x64, 0x66= 0xFF
I'm looking into this. I'm looking at your schematics and register settings and will get back to you if something stands out. How often do the spurious interrupts occur?
The interrupt for 2-3 times at an interval of 1 hour.
I see from your register contents that you are using the reading from temperature 2 to control your fans. Your TMIN is set at 15degC, temperature low limits at 10 degC, and temp low limits at 80 deg C. Please confirm. What are the contents of the interrupt status registers 0x41 and 0x42? As well as the temperature 2 reading register 0x21? Kindly read registers 0x3D, 3E and 3F as well.
The bits on the interrupt status registers are cleared on read of the status register if the error has subsided.
We are waiting for the reply. Many systems are having the same issue.