Help making my first sensor

[mattallen37]

Those are 1206, and I think Pololu used 0603 (1/4 the size). Unless you have done SMD soldering, and you are comfortable with that size, I recommend you use the more standard (among beginners anyhow) through hole type of resistor.

Those two should be the only ones that need to be replaced.

I do have a bit of a concern though, in that 82k pullups might be too weak for the sensor. If the sensor will only work with pullups that are too strong for the NXT, then you'll need to use an I2C bus repeater (or modify the NXT like Aswin did). For now though, replacing the pullups is definitely the first step (since it doesn't take much time or money, and is likely to work).

I would remove the 4k7 resistors (the two that need to be removed), and then solder some axial resistors to the header.

Since you shouldn't need a breadboard between the NXT and the IMU, you could probably just use half an NXT cable, and solder the wires directly to the IMU header.

[inxt-generation]

I've soldered plenty. I'm not exactly the best at that scale, but I've done it. I had a thought though, can I just remove the resistors on the board and put the replacements on a breadboard? I'm sure I have 82k through-holes. I don't mind being tied to a breadboard, at least for now. All I'd have to do is put two resistors across the SDA/SCL and the VIN pins on the breadboard, correct? Seems right to me.

[mattallen37]

That's what I'd do, except I'd skip the breadboard. I would solder the resistors directly onto the header (where the wires connect). You need one from SCL to VIN, and one from SDA to VIN.

[inxt-generation]

That's what I'd do, except I'd skip the breadboard. I would solder the resistors directly onto the header (where the wires connect). You need one from SCL to VIN, and one from SDA to VIN.

That's what I thought. I'm gonna skip any soldering for the moment though, other than getting rid of the resistors. Thanks.

[circuitmage]

Any update on this?

[inxt-generation]

I have other priorities. I'm gonna work on it if I have time, but I probably won't for a month or so. I still have several robots to build before Brickworld Chicago.

[circuitmage]

Ok. Just curious. Sounds like a good project. I am looking for some similar sensor capabilities, but have not started a project with them yet.

I too am wondering what CSBC is....

[inxt-generation]

Colorado Society for Blanket Crafting?
Clinchy Saurians Banging Cats?
Custom Sensor Brewing Club?

[rb95403]

Good morning!

Previously have made simple touch or light sensors for NXT following the advice in the "Extreme NXT" book. No problem.

Today, I tried to make a simple whisker touch sensor for the EV3, but, when a simple circuit is made, the "Port View" reads "port error". When I create a simple retail version program to display the raw value, no value appears. (Using raw value, I can get light sensor values.) The touch sensor method to obtain a raw value does not seem to work. I used the black and white wires ....

Am I missing something simple?

Will there be a new Extreme EV3 for homebrew sensors?

Any help is appreciated.

[mattallen37]

The EV3 seems to use sensor pin 2 as a sense line. It can probably drive it low (GND) to support e.g. the RCX sensors, but it doesn't seem to do so regularly.

I recommend using pin 3 (red) for the Gnd connection.