Discussion Overview
The discussion centers around powering a digital pen using a USB connection to a PC, exploring the necessary procedures and whether external circuitry is required. Participants also discuss the DTR pin and its potential role in power supply.
Discussion Character
- Technical explanation, Conceptual clarification, Debate/contested
Main Points Raised
- One participant inquires about the procedure for powering a digital pen via USB and whether external circuitry is necessary.
- Another participant suggests consulting the USB FAQ for additional information.
- A participant provides details on USB connector pinouts, explaining that pins 1 and 4 supply +5V power and that a peripheral can draw up to 500 mA from these pins.
- The same participant clarifies that the DTR pin is associated with the PC's serial port, not the USB port, and cautions against using serial port pins for power supply due to unspecified current capabilities.
- A participant expresses a preference for using USB over serial for powering the device.
Areas of Agreement / Disagreement
Participants generally agree on the use of USB for powering the digital pen, but there is some confusion regarding the role of the DTR pin and its applicability to the USB context.
Contextual Notes
There are limitations regarding the assumptions about current draw from the DTR pin and the implications of using serial port pins for power supply, which remain unresolved.
Who May Find This Useful
Individuals interested in USB power supply for peripherals, particularly those working with digital devices and circuitry design.