A remote Ethernet switch for my relay box - Versionsgeschichte

Dl8rds: /* Arduino Mega 2560 */

2017-06-10T17:45:40Z

‎Arduino Mega 2560

2017-06-04T21:25:15Z

‎Arduino Mega 2560

2017-06-04T21:11:08Z

‎Images

2017-06-04T20:37:54Z

‎Components

2017-06-04T17:28:18Z

‎Components

2017-06-04T17:27:01Z

‎Components

2017-06-04T17:25:56Z

‎Components

2017-06-04T17:19:15Z

‎Components

2017-06-04T17:17:42Z

‎Components

2017-06-04T17:13:07Z

‎Arduino ProMini

← Nächstältere Version		Version vom 4. Juni 2017, 21:11 Uhr
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	[[Bild:2017-06-04-RemoteEthernetSwitchboard8-7.jpg\|400px]] [[Bild:2017-06-04-RemoteEthernetSwitchboard8-8.jpg\|400px]]		[[Bild:2017-06-04-RemoteEthernetSwitchboard8-7.jpg\|400px]] [[Bild:2017-06-04-RemoteEthernetSwitchboard8-8.jpg\|400px]]
		+
		+	[[Bild:2017-06-04-RemoteEthernetSwitchboard8-9.jpg\|400px]] [[Bild:2017-06-04-RemoteEthernetSwitchboard8-10.jpg\|400px]]

@@ Zeile 29: / Zeile 29: @@
 Considerations and alternatives:
-* The LAS2GQ button switch has a LED status indicator ring. The datasheet does not say anything about the LED resistor and its value. Only after I measured it at 960 Ohm and did some experiments, I found out that it seemed to work: A driver stage such as the 8 channel ULN2803AGP Darlington transistor array seemed not necessary. Even though the max ratings of the GPIO pins are at 40mA, the required 52mA seem to work. Given that the Arduino ProMini makes sure to switch off the Arduino Mega after 30 seconds of inactivity, I assume the temporary overcurrent is not that destructive :-)
+* The LAS2GQ button switch has a LED status indicator ring. The datasheet does not say anything about the LED resistor and its value, which I measured at 960 Ohm. I=U/R tells me that the current will be 52mA, which is above the max ratings of the GPIO pins, so I decided to use a ULN2803AGP Darlington transistor array to reduce the load of the GPIO pins. The ULN datasheet says that the ideal use case would be as emitter switch, so I did that. The eight pins caused a bit of cabling salad, but it works fine :-)
 Components list:
@@ Zeile 51: / Zeile 53: @@
 * Diode 1N4148
 * Relay FRS1B-S 5V, 5€
 The values are rounded. Total costs: 150€

@@ Zeile 29: / Zeile 29: @@
 Considerations and alternatives:
-* The LAS2GQ button switch has a LED status indicator ring. The datasheet does not say anything about the LED resistor and its value. Only after I measured it and did some experiments, I found out that it seemed to work: A driver stage such as the ULN2803AGP Darlington transistor array seemed not necessary. Even though the max ratings of the GPIO pins are at 40mA, the required 52mA seem to work. Given that the Arduino ProMini makes sure to switch off the Arduino Mega after 30 seconds of inactivity, I assume the temporary overcurrent is not that bad :-)
+* The LAS2GQ button switch has a LED status indicator ring. The datasheet does not say anything about the LED resistor and its value. Only after I measured it at 960 Ohm and did some experiments, I found out that it seemed to work: A driver stage such as the 8 channel ULN2803AGP Darlington transistor array seemed not necessary. Even though the max ratings of the GPIO pins are at 40mA, the required 52mA seem to work. Given that the Arduino ProMini makes sure to switch off the Arduino Mega after 30 seconds of inactivity, I assume the temporary overcurrent is not that destructive :-)
 Components list:

@@ Zeile 29: / Zeile 29: @@
 Considerations and alternatives:
-* The LAS2GQ button switch has a LED status indicator ring. The datasheet does not say anything about the LED resistor and its value. Only after I measured it and did some experiments, I found out that it seemed to work: A driver stage such as the ULN2803AGP Darlington transistor array seemed not necessary. Even though the max ratings of the GPIO pins are at 40mA, the required 52mA seem to work.
+* The LAS2GQ button switch has a LED status indicator ring. The datasheet does not say anything about the LED resistor and its value. Only after I measured it and did some experiments, I found out that it seemed to work: A driver stage such as the ULN2803AGP Darlington transistor array seemed not necessary. Even though the max ratings of the GPIO pins are at 40mA, the required 52mA seem to work. Given that the Arduino ProMini makes sure to switch off the Arduino Mega after 30 seconds of inactivity, I assume the temporary overcurrent is not that bad :-)
 Components list:

@@ Zeile 29: / Zeile 29: @@
 Considerations and alternatives:
-* The LAS2GQ button switch has a LED status indicator ring. In the beginning I was not sure if the Arduino Mega could drive this LED with the max rating of 40mA, but it can. As an alternative it would be possible to use the Toshiba ULN2803AGP Darlington transistor array as a driver stage.
+* The LAS2GQ button switch has a LED status indicator ring. The datasheet does not say anything about the LED resistor and its value. Only after I measured it and did some experiments, I found out that it seemed to work: A driver stage such as the ULN2803AGP Darlington transistor array seemed not necessary. Even though the max ratings of the GPIO pins are at 40mA, the required 52mA seem to work.
 Components list:

@@ Zeile 29: / Zeile 29: @@
 Considerations and alternatives:
-* The LAS2GQ button switch has a LED status indicator ring. In the beginning I was not sure if the Arduino Mega could drive this LED, but it can. As an alternative it would be possible to use the Toshiba ULN2803AGP Darlington transistor array as a driver stage.
+* The LAS2GQ button switch has a LED status indicator ring. In the beginning I was not sure if the Arduino Mega could drive this LED with the max rating of 40mA, but it can. As an alternative it would be possible to use the Toshiba ULN2803AGP Darlington transistor array as a driver stage.
 Components list:
@@ Zeile 39: / Zeile 39: @@
 * Neutrik Ethernet socket, 5€
 * 9x LAS2GQ switches with red LED ring, 55€ https://www.reichelt.de/?ARTICLE=108416
 : Note: The 12V version also works with 5V
 * 8x 10k PullDown Resistors for the switches

← Nächstältere Version		Version vom 4. Juni 2017, 17:17 Uhr
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	== Components ==		== Components ==
		+
		+	Considerations and alternatives:
		+
		+	* The LAS2GQ button switch has a LED status indicator ring. In the beginning I was not sure if the Arduino Mega could drive this LED, but it can. As an alternative it would be possible to use the Toshiba ULN2803AGP Darlington transistor array as a driver stage.
		+
		+	Components list:

	* Arduino ProMini, 5€		* Arduino ProMini, 5€

← Nächstältere Version		Version vom 4. Juni 2017, 17:13 Uhr
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	[[Image:2017-06-04-ArduinoProMiniSchaltbild.jpg\|600px]]		[[Image:2017-06-04-ArduinoProMiniSchaltbild.jpg\|600px]]
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		+	=== Arduino Mega ===
		+
		+
		+	[[Image:2017-06-04-ArduinoMegaSchaltbild.jpg\|600px]]

	== Operational observations ==		== Operational observations ==