Comments on: Meet the Plug Shield http://jeelabs.org/2009/11/05/meet-the-plug-shield/ Computing stuff tied to the physical world Mon, 06 Feb 2012 13:55:24 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: jcw http://jeelabs.org/2009/11/05/meet-the-plug-shield/#comment-650 jcw Thu, 05 Nov 2009 13:04:15 +0000 http://news.jeelabs.org/?p=3380#comment-650 <p>For some plugs (most of the current ones, in fact), no regulator or level converter is needed. For others such as the UART Plug, 5V is not an option. Note that mixing 3.3/5V devices on an I2C bus can be problematic. I've completely switched to 3.3V over here, but you're right that it is not always needed for Arduino-based configurations.</p> <p>So for a Clock Plug for example, you don't need the fully assembled Plug Shield. Just the PCB with a few jumpers will do. Or you can tie your plugs directly to the Arduino and forego the shield altogether, of course. It's all going to depend on which plugs you use.</p> <p>I've got a couple of other plugs planned with sensor chips which are not 5V tolerant, so this will become more relevant later. To avoid confusion down the road, I've added a note to the documentation pages of those plugs which can also be used at 5V.</p> <p>Thanks for pointing this out.</p> For some plugs (most of the current ones, in fact), no regulator or level converter is needed. For others such as the UART Plug, 5V is not an option. Note that mixing 3.3/5V devices on an I2C bus can be problematic. I’ve completely switched to 3.3V over here, but you’re right that it is not always needed for Arduino-based configurations.

So for a Clock Plug for example, you don’t need the fully assembled Plug Shield. Just the PCB with a few jumpers will do. Or you can tie your plugs directly to the Arduino and forego the shield altogether, of course. It’s all going to depend on which plugs you use.

I’ve got a couple of other plugs planned with sensor chips which are not 5V tolerant, so this will become more relevant later. To avoid confusion down the road, I’ve added a note to the documentation pages of those plugs which can also be used at 5V.

Thanks for pointing this out.

]]> By: Simon Sapin http://jeelabs.org/2009/11/05/meet-the-plug-shield/#comment-649 Simon Sapin Thu, 05 Nov 2009 12:16:27 +0000 http://news.jeelabs.org/?p=3380#comment-649 <p>"There is a regulator to supply 3.3V to the port connectors on-board, as well as an I2C bus level converter." Do we <em>need</em> these to use JeePlugs with an Atmega running a 5V? The DS1340Z datasheet (for the RCT plug) seems to say it tolerates up to 5.5V on the supply, SDA and SCL lines but i'm not sure.</p> “There is a regulator to supply 3.3V to the port connectors on-board, as well as an I2C bus level converter.” Do we need these to use JeePlugs with an Atmega running a 5V? The DS1340Z datasheet (for the RCT plug) seems to say it tolerates up to 5.5V on the supply, SDA and SCL lines but i’m not sure.

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