eeros_architecture:hal:scaling
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eeros_architecture:hal:scaling [2017/05/11 12:11] – [Configuring an Analog Input] graf | eeros_architecture:hal:scaling [2022/05/06 21:09] (current) – jonasfrei | ||
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====== Scale and Range of Analog Signals ====== | ====== Scale and Range of Analog Signals ====== | ||
- | Within | + | Within |
===== Configuring an Analog Output ===== | ===== Configuring an Analog Output ===== | ||
To configure such a channel follow these steps: | To configure such a channel follow these steps: | ||
- Read the datasheet of your hardware and note the upper and lower limits of the analog output voltage. | - Read the datasheet of your hardware and note the upper and lower limits of the analog output voltage. | ||
- | - Enter this limits in the configuration file under '' | + | - Enter these limits in the configuration file under '' |
- Get the upper and lower limits of the digital values of the converter from the datasheet. | - Get the upper and lower limits of the digital values of the converter from the datasheet. | ||
- Enter this limits in the configuration file under '' | - Enter this limits in the configuration file under '' | ||
- Write a small digital value to the analog output directly (not through eeros). That is, if your are using comedi for instance, you use a user interface and write a value of 1000 to one of its analog outputs. | - Write a small digital value to the analog output directly (not through eeros). That is, if your are using comedi for instance, you use a user interface and write a value of 1000 to one of its analog outputs. | ||
- | - Record this digital value it in the configuration file under '' | + | - Record this digital value in the configuration file under '' |
- Measure the resulting voltage with a multimeter and record it in the configuration file under '' | - Measure the resulting voltage with a multimeter and record it in the configuration file under '' | ||
- Repeat this with a large digital value close to the upper limit. For this you have to know the range of your digital-to-analog converter. | - Repeat this with a large digital value close to the upper limit. For this you have to know the range of your digital-to-analog converter. | ||
- | - Record this digital value it in the configuration file under '' | + | - Record this digital value in the configuration file under '' |
- Measure the resulting voltage with a multimeter and record it in the configuration file under '' | - Measure the resulting voltage with a multimeter and record it in the configuration file under '' | ||
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+ | If you know the scale and offset of your channel you could give these values directly as: | ||
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===== Configuring an Analog Input ===== | ===== Configuring an Analog Input ===== | ||
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To configure such a channel follow these steps: | To configure such a channel follow these steps: | ||
- Read the datasheet of your hardware and note the resolution of your encoder for a full turn. | - Read the datasheet of your hardware and note the resolution of your encoder for a full turn. | ||
- | - Enter this limits in the configuration file under '' | + | - Enter this limits in the configuration file under '' |
- | - Get the upper and lower limits of the digital values of the converter from the datasheet. | + | - The '' |
- | - Enter this limits in the configuration file under '' | + | |
- | - Enter a small analog voltage value to the analog input and note it in the configuration file under '' | + | |
- | - Record the resulting digital input value of the analog-to-digital converter in the configuration file under '' | + | |
- | - Repeat this with a large voltage close to the upper limit. For this you have to know the range of your analog-to-digital converter. | + | |
- | - Record this value it in the configuration file under '' | + | |
- | - Record the resulting digital value in the configuration file as '' | + | |
- | The resulting channel configuration for a 16bit ADC might look like: | + | The resulting channel configuration for an encoder |
< | < | ||
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eeros_architecture/hal/scaling.1494497460.txt.gz · Last modified: 2017/05/11 12:11 by graf