user15699: I am looking for a solution regarding the gsr, accelerometer, heart rate, skin temperature. From this other question seems that Grove isn't clear enough with their documentation. So I am looking for other ideas. I already know cooking hacks and I am afraid that with their hardware I can't make my Arduino wearable and comfortable enough, because at the end I'd like to attach a lithium battery with a case (that's why I don't want the extra bulk of a shield).
More details of what I am looking for.
Accelerometer:
Range: +/- 1.0g
Minimum resolution: 0.01g
Galvanic Skin Response
Range: 56k Ohms to 20M Ohms 
Two-standard-deviation error of +/- 4.0% otherwise
Skin Temperature 
Range: 20.0°C to 40.0°C
Resolution: 0.05°C
Error: +/- 0.8°C

user10907: The accelerometer may be pretty easy (since it may not need to be in close contact with the person), but the GSR and skin temperature will need to be touching the person to work.
The first thing you will want to do is to identify the sensors that you want to use, and then come up with some ideas for how to make them wearable so that you can measure the parameters that you're looking for. Will you be able to attach them with straps, or does the attachment need to be more subtle or more comfortable? Small breakout boards are handy, but they may make the sensor uncomfortable to wear.
I'd suggest taking at look at the Adafruit site for some ideas on wearables and sensor interfacing. There is a lot of useful information there and much of it focuses on Arduino based designs. For the most part the sensors they sell and use are well documented either with data sheets or code (or both).

user10664: I ran into a similar quandary when making a prototype for a device that needed real test-data from an external, glove-worn accelerometer. I wound up running the data/power/etc pins from my Arduino board to a female RJ-45 jack (I've used a telephone jack on another project where only 4 wires were needed). Then I cut an old cat-5 network cable in half and soldered the wire-ends to data/power/etc pins on my external sensor board. This allowed me to separate one component's wiring scheme from the other's. (FYI: longer lengths of cable between components does increase the risk of noise/interference corrupting digital signals. This can usually be resolved by reducing data rates or by adding a few resistors/capacitors to filter the signal, but I have limited knowledge on this)
Even if you don't have any old RJ45 cables/jacks laying around, it can really help to find some way to "modularize" the various pieces that will be working together when your device is complete. If you're familiar with object oriented programming, think of it as "designing an interface" for each component. Then, even if you completely redesign the wiring for a particular component, you only need to ensure that your "interface" (aka connection) is the same, and you wont need to resolder anything on the other end of the line. 

15699: <p>I am looking for a solution regarding the gsr, accelerometer, heart rate, skin temperature. From this <a href="https://arduino.stackexchange.com/questions/601/grove-sensors-without-a-grove-shield">other question</a> seems that Grove isn't clear enough with their documentation. So I am looking for other ideas. I already know cooking hacks and I am afraid that with their hardware I can't make my Arduino wearable and comfortable enough, because at the end I'd like to attach a lithium battery with a case (that's why I don't want the extra bulk of a shield).</p>

<p>More details of what I am looking for.</p>

<p>Accelerometer:
Range: +/- 1.0g
Minimum resolution: 0.01g</p>

<p>Galvanic Skin Response
Range: 56k Ohms to 20M Ohms 
Two-standard-deviation error of +/- 4.0% otherwise</p>

<p>Skin Temperature 
Range: 20.0°C to 40.0°C
Resolution: 0.05°C
Error: +/- 0.8°C</p>
 10907: <p>The accelerometer may be pretty easy (since it may not need to be in close contact with the person), but the GSR and skin temperature will need to be touching the person to work.</p>

<p>The first thing you will want to do is to identify the sensors that you want to use, and then come up with some ideas for how to make them wearable so that you can measure the parameters that you're looking for. Will you be able to attach them with straps, or does the attachment need to be more subtle or more comfortable? Small breakout boards are handy, but they may make the sensor uncomfortable to wear.</p>

<p>I'd suggest taking at look at the <a href="http://adafruit.com" rel="nofollow">Adafruit</a> site for some ideas on wearables and sensor interfacing. There is a lot of useful information there and much of it focuses on Arduino based designs. For the most part the sensors they sell and use are well documented either with data sheets or code (or both).</p>
 10664: <p>I ran into a similar quandary when making a prototype for a device that needed real test-data from an external, glove-worn accelerometer. I wound up running the data/power/etc pins from my Arduino board to a female RJ-45 jack (I've used a telephone jack on another project where only 4 wires were needed). Then I cut an old cat-5 network cable in half and soldered the wire-ends to data/power/etc pins on my external sensor board. This allowed me to separate one component's wiring scheme from the other's. (FYI: longer lengths of cable between components does increase the risk of noise/interference corrupting digital signals. This can usually be resolved by reducing data rates or by adding a few resistors/capacitors to filter the signal, but I have limited knowledge on this)</p>

<p>Even if you don't have any old RJ45 cables/jacks laying around, it can really help to find some way to "modularize" the various pieces that will be working together when your device is complete. If you're familiar with object oriented programming, think of it as "designing an interface" for each component. Then, even if you completely redesign the wiring for a particular component, you only need to ensure that your "interface" (aka connection) is the same, and you wont need to resolder anything on the other end of the line. </p>
