I am currently busy designing a Gadgeteer module board for myself and can easily make a few extra’s if there are other people that would also be interested…
It is a module capable of making accurate measurements of extremely low currents (micro and nano-Ampere range). It contains some precision op-amps and even a 16 bit differential A/D in order to achieve this. The purpose of the module (in my case) would be to estimate expected battery life from a circuit running in low power mode from a small battery. But I think my module will have other uses as well such as measuring strain gauges, 4-20mA sensors, precision resistance measurements etc.
The first part of the circuit is based on a design that appeared in a magazine article which you can read online here: http://www.eevblog.com/projects/ucurrent/
I used the circuit found there but laid it out as a Gadgeteer module board and included a 16 bit differential A/D on the board as I needed better resolution that the 10 bits that standard Gadgeteer mainboards offer.
I think this module will be usefull to use in conjunction with the “Your PC becomes your gadgeteer mainboard” feature that GHI are inrocucing soon. (See https://www.ghielectronics.com/community/forum/topic?id=11713)
Since I am making some PCB’s for myself I thought I might as well make a few extra’s and offer them to other forum members as well at a cost of about $20. This post is merely to probe if there would be any interest in something like this from other members. I would then know how many additional boards and components to order. Once I get the first board assembled I will post some pictures and test results.
PS: Oh, and at the same time I also made myself a gadgeteer module that allows you to interface a 3V3 Gadgeteer mainboard with a 5V I2C chip. It consist for some N-Channel MOSFETS to do a bidirectional of the SDA and SCL lines and a resistor divider network to allow PIN 3 interrupt and a general input on pin 6 as well. I can also make some extras of this board if anyone is interested. It will cost about $10.