Discussion Overview
The discussion revolves around generating a 0-20mA output from an Arduino Duemilanove with ATMEga328 for use in a speed indicator. Participants explore the necessary hardware and configurations to achieve this current output, considering both theoretical and practical aspects.
Discussion Character
- Exploratory
- Technical explanation
- Debate/contested
Main Points Raised
- One participant inquires about using an Arduino pin to input 0-20mA into a speed indicator, noting the need for external hardware due to the Arduino's voltage output.
- Another participant questions the relationship between current and voltage, as well as the effects of series and parallel circuits on current.
- A suggestion is made that a low-tech solution could work, depending on the input impedance of the speed indicator, and proposes using a resistor to limit current while measuring voltage to back-calculate impedance.
- There is a mention of a total impedance requirement of 250 Ohms, with a recommendation to use a 270 Ohm resistor to limit current to below 20mA.
- One participant requests additional information about the speed indicator, specifically whether it operates on a 0-20mA or 4-20mA input.
- Another participant confirms that a 4-20mA input is acceptable, as it is an industry standard.
Areas of Agreement / Disagreement
Participants express varying views on the specifics of the speed indicator's input requirements, with some suggesting a 0-20mA output while others mention the 4-20mA standard. The discussion remains unresolved regarding the best approach to achieve the desired current output.
Contextual Notes
There are limitations regarding the assumptions about the speed indicator's input impedance and the accuracy required for the output. The discussion does not clarify the exact characteristics of the speed indicator or the implications of using different resistor values.
Who May Find This Useful
This discussion may be useful for individuals working on projects involving Arduino and current output configurations, particularly in applications related to speed indicators or similar devices.