USB link neatly measures temperature

摘要

Figure 1 shows a convenient and neat way to measure temperature using the USB of a PC. An ADM-1023 IC senses the temperature, and an Anchor Chips EZ-USB AN2131SC μC provides control. The ADM 1023 is a low-cost device with an accuracy of 1℃ and a resolution of 0.125℃ The IC is a two-channel device that can measure its own local temperature and the temperature of a remote location. You obtain remote-temperature sensing by connecting a remote thermal diode between the D+ and D- pins of the μC. You can locate this remote diode (for example, a diode-connected 2N3906) in a hot spot that can be as far as 100 ft from the ADB1023. However, for distances greater than 12 in., you should use twistedpair cable. For distances greater than 12 ft, you should use shielded twistedpair cable, such as microphone cable.