Is there a direction for the current flow? The A…Z marking seem to indicate that it is directionless.
If the current flows in the wrong direction you will get a negative voltage across the shunt, unless the amplifier makes the voltage always positive.
Looks good. Maybe a place to insert probes if one wanted to use this as a way to tap in and measure using external instruments?
Yeah, the amplifiers does not like negative voltage. Will add “Power In” and “Power Out”. But now it’s 12AM and time for bed. 
I can add that. The voltages will be strange and not easily converted to amps though. Over the resistor there will be 15mV per amp. On the output of the amplifier there will be 1.5V per amp…
The software guy says “diode(s)?”.
Excellent that was exactly what I was thinking of. No doubt the Gadgeteer community here knows how to rock and roll. I’ll be ordering some of these bad boys when they become available as right now I’d love to get an idea as to what exactly is happening in the device I’m testing as there seems to be a power issue, but with a module like this it would be so easy to confirm what and where it is.
THANKS!!!
Naa, the chip can handle relative negative voltages, with Sense+ being less than Sense-, but it will not give you a current reading. No damage, but no work…
Added test points and In/Out labels.
Looks great. Now if only you could plug an LCD directly into it… 
CurrentMod? Sounds like you’re trying to modify the current instead of measure it… CurrentTap?
I thought that CurrentModule was too long.
But unfortunately the PCB went to Seeed last night, so too late to make changes… 
Also sent MegaMux, and a contactless IR thermometer module.
Please let me know when those become available.
Ordering parts today, will take one week to arrive. PCB should arrive in two weeks, one week for Seeed to make PCB, one week DHL shipping. Driver should be fast and testing easy. Will let you know ASAP when I’m ready to ship.
Nice!
I assume this is a digital MUX? What are the specs?
You know what they say about great ideas…
At Microsoft Research, we have also been looking at the issue of the power bugs that people run into when working with embedded platforms such as Gadgeteer. We have been prototyping a power monitoring kit to help users better understand power consumption, and identify and resolve power-related problems. During his internship at the lab, Jordi Solsona Belenguer has developed a set of hardware-add-on modules that make it easy to sense power consumption of the mainboard and individual modules with high accuracy.
Ill let Jordi answer questions about implementation details in a follow-on post, but basically the kit consists of a number of boards that can be added between the mainboard and modules to provide power sensing. We have developed boards in several form-factors, including a mainboard add-on board that allows every socket to be monitored, a single-module sensing board (similar to GMods design), and an Arduino-shaped shield. We are using high-precision power-sensing ICs with an I2C interface that support built-in sample averaging and interrupt capabilities. The sensing boards can either be plugged into a socket I on the mainboard to feed the data back to the application, or connected to a custom interface board that provides the data directly to a PC through a simple ASCII protocol via USB. The idea behind the custom interface board is that you might want to monitor and graph the power consumption on your PC at high speed and high resolution, without affecting the normal operation of your application. The interface board is powered separately, which allows it to carry on working even if the mainboards power supply is having problems (allowing those problems to be identified).
What we would really like to do at this stage is to work with this community to better understand the issues surrounding power bugs, and how we can build tools that end users identify and fix them. Without wishing to de-rail existing efforts, we would like to make available our own designs for beta-testing and feedback once they have been verified and documented.
We need to figure out the logistics of how best to distribute the boards and manage availability. For the first batch Im proposing that anyone that has commented on this thread so far, as well as anyone that orders one of GMods boards will be first in line to evaluate our boards. In return we may ask recipients to briefly report on how our system was useful or not useful for power debugging, since (as with all our work) we may want to publish the results in an academic conference in due course.
What do you think?
Nic
@ Nicolas - Cool stuff - but shouldn’t it be black? Sorry couldn’t resist 
Nic,
Wow! It looks like you guys have been busy on this problem. With the introduction of the CP7 and other power hungry modules lately, this is becoming a bigger problem than in the past. It’s nice to know you guys are already ahead of the issue.
One thing I’ve come to the realization of in recent months is that Gadgeteer really needs a feature such as that of GO! that allows the mainboard to turn power on/off to modules at runtime. Several of us have built tablet projects around the CP7 display. I would like to be able to have something attached to every socket on the Hydra within and be able to have my applications decide which modules get power without me having to open up the enclosure and unplug modules. With this level of control combined with being able to measure or by just using static configuration max values, it would be possible to give a much higher level of visibility to the developer regarding potential power issues from the beginning.
I’d love to test out your modules.
@ Nicolas
Very nice! I must say that the module to sense all the spider sockets are scary.
What power sense chip are you using?
@ ianlee74
The MegaMux is an analog multiplexer that gives you 48 analog channels from one “A&Y” socket. More info here: http://www.tinyclr.com/forum/topic?id=8588&page=2#msg85546
Hmm, another module opportunity?
No. I want it built into the mainboard as part of the Gadgeteer spec A module would be a good start though 
Ah, Megamux… I remember the module but had forgotten the name.
Naa, I was thinking two P channel FETs on a DaisyLink module, so you can chain as many ModuleSwitchModules as you need…