Reddit mentions: The best sensor blocks

I actually didn't know what I wanted to build first, I'm a software engineer so I was exited to actually write some software and see an object moving hahaha, so eventually a Car came to mind, since it's fun to see it go and move around.

So, to start I looked in amazon for a chassis and wheels and I found this kit that looked pretty simple and functional, so I got that, and then since it only brings 1 motor, I got this to be able to move to the sides, at this point I had no idea how to make that work, but I just figured stuff up on the go, I didn't know how to move the motor so I searched for youtube videos and found out that I needed a motor controller again, amazon was my best friend haha, I also got this battery.

After that I was able to make the Car run, the problem was, I needed some kind of way to guide it, because randomly moving around wasn't that fun, so I came out with the design of the robot looking around I found this module and it was just what I needed, I had a few servos and other components from a mix kit that I got with the Arduino, and I used that (and my girlfriend's help with deciding where to put the pices to make them look nicer) to build the robot that you saw on my first post and then I used this BT module to build the manual mode that you can see in my second post and you know the rest of the story, I'm not sure if I missed something, but let me know and I can answer any question :)

I got this cheap OLED screen for $10.99. The text looks nice and it's able to display plenty of information for only being 0.96" diagonal. I got the blue colored one just because it was first available, but they have different colors.

It comes pre-soldered and you just need four jumper wires. Easy.

Only UAT, ES, CPU temp, and towers displayed for now. It can easily be extended to show more information.

I wrote this Python script to display the information and update once per second. It gets the data from Stratux via webinterface, parses the JSON, and draws the information on the screen.

Set the script to start up on boot, and now don't have to look at the iPad to get reception stats. Neat.

And just for fun, the startup screen: http://i.imgur.com/qIUOzkK.jpg

Just an arduino with a smoke/flammable gas detection module and ssr. I think it took like 5 lines of code. All you need to do is loop and read a value off a pin. When it hits your threshold you set the ssr pin to false and save a Boolean to make sure you don't turn it back on until the unit is reset.

Only issue I've had thus far is hairspray will sometimes set it off.

Edit: here is the smoke detection module: Uxcell MQ-2 LM393 Chip Smoke Gas Sensor Module for MCU, DC 5V https://www.amazon.com/dp/B00GYUSP4S/ref=cm_sw_r_cp_api_DiHizbTC7PCY4

The ssr will need to be sized based off your hardware. Just make sure the trigger is dc and between 3-5 volts. Make sure it is large enough to easily handle the current draw (remember it is at 120v so the current will be different than the draw of your hotend a (less). )

Edit 2: Just in case you decide to do this and look back - lesson I learned is that it's worth including an external reset switch. I have to reach to the back of my enclosure and unplug/plug back in the arduino each time it triggers (which hair spray and I recently discovered Denature Alcohol will both sometimes trigger it). At some point I'll run a wire off the reset switch and put a small microswitch near the front of the enclosure so I can just press that.

No worries! It's exciting to me that you're so excited lol.

Just a heads up, I'm gonna try and set up a different type of sensor for the water level reading, as the current water sensor gets some false readings when a pine needle floats onto it.

So if you want to have one on hand if it turns out to work better, here's the type of distance sensor I'll be trying out: https://www.amazon.com/HC-SR04-Ranging-Detector-Ultrasonic-Distance/dp/B01GNEHJNC?ref_=fsclp_pl_

Even if it doesn't work out for this application, it's a great sensor to have on hand.

> I use a RTC break-out chip for keeping track of time

As I mentioned in my other post, I first tried this route and gave up. I just let the "real" home automation controller do the scheduling as it was significantly easier to make schedule changes.

One other thing I should have mentioned that you might want to include just because why not.... Get a one-wire temperature probe like this one and wire it up to a display like this. If you do go the home automation route, you can "broadcast it" so to speak using a plugin like this.

BTW, if you don't want to live in the apple ecosystem, there is also HomeAssistant (/r/homeassistant). You can run it on a raspberry pi. I'm pretty sure there is also equivalents for whatever google's home automation solution is but I can't speak to that...

https://www.amazon.com/gp/product/B00O2LKEW2/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

This screen is pretty great, there's a python library for it too

Thanks for the ideas!

I've been thinking and looking for a way to be able to use at least one extra button for years. So far no success, since I can't move my legs or any other body parts enough for the devices you described above, but I'll keep searching. (I found lately that there are muscle sensors, and if they can be set to extremely sensitive to muscle activities, I could use them for many ways.)

I understand only half of what you wrote in the autohotkey part (sorry, I'm Hungarian), but yes, the virtual keyboard can be toggled via a hotkey, so this might work.

Although, I got an idea while I was writing this comment. Is it possible to do the following? If I click and hold a button on the virtual keyboard, the in-game camera will rotate (by mouse moving), and when I release that button it won't. This way it wouldn't be necessary to toggle the virtual keyboard, it could be turned on all the time.

Not sure what type of electronics you would be using, but if you have a microcontroller (Arduino, etc.), I suggest something like this ranger.

It uses a high frequency pitch (not audible) to time out the distance to an object. I have used them before with my Arduino Uno and they work very well. Fairly accurate too. Just a suggestion.

Ninja EDIT: Link issue fixed.

> At a glance it doesn't look like hobbyist stuff. Looks like you brought it off shelf.

It is called knowing people with good tooling that can help me make stuff :-) Thanks!

> I would suggest your original approach of serving html/JS as control interface. I think that LCD/keypad adds way too much bulk to the overall package.

I might think about it because I agree about the bulk. In retrospect, I kinda wish I went with those tiny little 0.96" I2C OLED displays you see floating around on amazon. They are much higher quality than those bulky 20x4 displays My original thought was they'd be too bright and there would be times I'd be fucking around with this thing at night with a flashlight (while intoxicated after sitting around a campfire). I might go with the small display anyway because that 20x4 display is pretty god damn heavy and is already looking to have some kind of display issues...

With JS I could do a lot of the computations on the phone (eg: let the javascript compute the estimated runtime). Plus the web already has a very nice way of doing input-- it comes with all the forum elements you need :-). Doing it with the keypad meant I had to write the interface from scratch with zero support from a framework (no event library, no "text box" library, not even a system-wide way to make delete work....) .

In my head the trade off was battery life, which might get sucked up by the WiFi chip (which is a joke because the stepper motor draws 10x->100x more power than the MCU and it does so constantly). A design goal for this is to hike up an abandoned logging road in the middle of the cascade mountain range, set this up in the daytime and have a timer that activates the whole thing so it can shoot a starfield timelapse over an 8hr period at night. Think "30->40 degree temps at night" (which makes lipo batteries hard to use).... The power supply for this is a 4 or 5 pound 12v lead acid battery that I have to lug up with me... This fucker has to be rock solid and absolutely has to work because I do not want to wake up in the morning, hike back up and find out that it fucked up. You only get a handfull of moon-free, clear skies with the milky way out every year to work with...

I absolutely agree about a co-processor--it would make this stuff way smoother. I keep plotting how I might modify my stepper motor board to add one... I'd have 3 pins to play with, which should be enough for I2C or SPI...

> If I am doing things like this I would not use a belt driven mechanism.

I started to consider this after I got the slider dolly. I am almost thinking you could get away with just having the camera mount hang down from a long copper pipe or something. "Train track" would work too for some use cases but it might not be smooth motion.

The big constraint about my use case is stability. You have a camera shutter open for 30 seconds. Any wind or vibration will fuck up your crystal clear shot of the milky way.

The other constraint is that I have to hike that shit in, sometimes via bushwhacking -- so a long slider track would make for a cool shot but very hard to put on my back and scramble up a steep hill with.

I would say about $25-$30 with parts and everything. Once you have the code for one, putting it on others would be quick and simple. It would be a good option for future projects as well since you could just add other things to the board.

Screen

Temp sensor

Get started by prototyping with an arduino.

I would imagine you would want to use a screen like this:

https://www.amazon.com/Diymall-Yellow-Arduino-Display-Raspberry/dp/B00O2LLT30/ref=sr_1_6?ie=UTF8&qid=1550895612&sr=8-6&keywords=arduino+screen

I was under the impression that the one I was using could handle 5v? The original test on a breadboard was from 5v... I can change and hopefully didnt fry it yet if I a wrong.

Well, you could connect something like this. It's not an active buzzer, so you would use PWM to drive it at your chosen frequency.

this appears to be [the ultimate.](
http://www.amazon.com/Generic-DYP-ME007Y-Ultrasonic-Sensor-Module/dp/B00CXKKO6U)
Water proof with detachable sensor. crossing my fingers they ship to germany :)

I'm using a diymall 128x64 oled in that setup. should be a few bucks through some place like aliexpress [amazon link]

I could see this happening in the same way you might build a custom macro pad. You would need to wire everything up and connect it to something like a Teensy 2 controller.

Look into custom keyboards, there are some programs out there that let you customize the layout and all that.

It looks like one of these.

It's a .96" oled display with an i2c interface. The underlying controller is an SSD1306 and by searching for that you can find lots of code for the ESP8266.

if you don't find a ready made one I saw these awhile ago https://www.amazon.com/SunFounder-Sensor-Module-Arduino-Raspberry/dp/B013G8A76E/ref=sr_1_2?ie=UTF8&qid=1519161719&sr=8-2&keywords=natural+gas+detector+module

add them to a controller (nodemcu/raspi/arduino) and have it send the signal to a central controller via wifi. personally I'd use nodemcu, mqtt, and home assistant as I already have that pumping current and temperature settings into my system. Automating off of that would be easy enough...

Helloo theere....

i'm usinig these:

https://www.amazon.com/Diymall-Voltage-Sensor-Dc0-25v-Arduino/dp/B00NK4L97Q

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addding 300 to the ADC value gets me back to accurate........

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Because the maximum you can feed into the pin is 3.3v which is 16.5 on the voltage converter........

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12.89 from battery 2.56 into the board......

so a perfect 5 scaling factor....

For the OLED

Check out the mini 05, the Pico, or even the Teensy.

https://www.amazon.com/dp/B00O2LKEW2/ref=cm_sw_r_sms_awd_x_AID7xb5PTG0ZH

Mine's blue; there are other colors too.

Teensy 2.0 ++ 46 I/O pins if you need them.

https://www.amazon.co.uk/SunFounder-TCS3200-Recognition-Arduino-Raspberry/dp/B013QUDG3S/ref=sr_1_1?ie=UTF8&qid=1464246926&sr=8-1&keywords=colour+sensor

Get a NodeMCU D1 mini. it's a tiny esp8266 with built in microusb port and many input/output pins. Costs $4-8. The screen is listing below requires only four pins two operate using i2c protocol with the Wire library. Costs $2-5

Diymall 0.96" Inch Yellow Blue I2c IIC Serial Oled LCD LED Module 12864 128X64 for Arduino Display 51 Msp420 Stim32 SCR https://www.amazon.com/dp/B00O2LLT30/ref=cm_sw_r_cp_api_AJxHyb8WHR49A

How would I connect the teensy 2.0 to my switches?

This is the one you are talking about right? https://www.amazon.com/PJRC-Teensy-2-0/dp/B00NC4302Q/ref=mp_s_a_1_4?keywords=teensy+2.0&qid=1565571740&s=gateway&sr=8-4

i just got one of these they are dirt cheap https://smile.amazon.com/gp/product/B00O2LLT30/ref=oh_aui_detailpage_o02_s01?ie=UTF8&psc=1

Radar. Unless the beam is being broken by a mirror.

https://www.amazon.com/Smraza-Ultrasonic-Distance-Mounting-Duemilanove/dp/B01JG09DCK

Am I the only one on Reddit with Google ?

I'll try to get a diagram tonight, unfortunately my tinkering time for this morning has now expired, so I must go do other things. But in short:

It's a 4 pin OLED, doesn't SPI need 3 pins to communicate? CS, CLK, and Data? Or am I mistaken in this case? (It seems I might be, as I look now, someone on that amazon page is using spi. hmmm.)

I tried putting the resisters inline as you suggested, now it is as if the screen weren't connected at all.

I currently have:

A4 -> SCL
A5 -> SDA
GND -> GND
5V -> VCC