Let's Make Robots!

Electronics question: LEDs on a slightly unpredictable power supply

Hi guys, Way off topic, but you guys have been so helpful in the past, and i KNOW you know the answers, so one cant but ask!

We are doing a camper van conversion, and i have found some sweet "decking lights" for internal lighting.

They are sealed, "3LEDs and a resistor", units, designed to run at 12V (off a transformer, the junction box is a simple parrallel arrangement)

Problem is, the vehicle battery will produced between 11 and 14V depending on charge condition and if the alternator is running.

Monitors the weight of a pet, Logs data and provides visual feedback
So our (My girlfriends) cat has a hyperactive thyroid. The over abundance of thyroxin means she cant regulate her weight and without keeping it in check she will … Read more

Scavange/reverse-engineer ALL the things!

Im sure most of us recover parts from where they can be scavanged

I recently picked up a "broken" printer/scanner from work. Ive pulled out a whole stack of working DC motors with encoders, belts, pulleys, cogs and rubber wheels.

It also has a cool looking little strip light which must be the light source for the scanner. Its like a flourescent tube, but tiny and slightly flexible.

Cannibalizing a broken printer/scanner. Suggestions?!

My boss asked if i wanted a partially working printer scanner combo jobby today. Dont think he was expecting me to rip it apart for parts.

Ive only got SO far into pulling it to pieces, i will have to go and get a complete Torx driver set tommorow, ive gone as far as i can with >T15.

Anyone got any suggestions as to what i should do with this thing?!

Thoughts on reverse engineering a wind speed sensor

A friend of mine wants me to make him a weather monitoring station. Temperature and light leves are easy peasy, but ideally wind would be useful too (this thing is going to have a real life purpose!!)

i found this little fellah on fleabay

http://www.ebay.co.uk/itm/Wind-Speed-Sensor-For-Use-With-Wireless-Weather-Station-N25FR-/190973703805?pt=UK_Home_Garden_Weather_Stations&hash=item2c76eb767d

 

Constant reading of an analogue Value. Mechanical sympathy?

Over on my Pet weighing project, i am  using a PIR sensor to detect approach of the "subject". Once the PIR sensor goes high, the sketch takes a "base" value, and then takes the highest reading as its "read" value.

I think the PIR sensor is playing up, or maybe its thestrain gauges bouncing around all over the place....

Arduino Vs Strain gauge

Hi all, thanks for looking!

Im building a project (not a robot sorry) which is using strain gauges. I have found this EXCELLENT guide online:

http://www.deferredprocrastination.co.uk/blog/2013/reading-strain-gauge-scales-with-arduino/

Ive built my project up on a breadboard, to see if my shiny new INA125PA works! It appears to, but i have a couple of potentially noobish questions! Ive set my sketch up to read A2 only currently. It is serialprint-ing analogue reads from the Pin, and not doing any fancy pants processing yet.

Seek light & avoid obstacles
Using a
Update, 21/01/2014 I found that the ultrasonic sensor struggles with "box" obstacles towards its front flanks, probably due to reflection. Therefore to stop it … Read more

Interrupt causes program to freeze?

Ive just added some bump sensors to my bot, simple switches. I have added them to interrupt pins so that the bot CANT drive into stuff. (i cant forget to include monitoring the bumps to every section of code)

Now i realise that one should always include ALL the code when posting to a forum asking for help, but there is an awful lot of it at the moment, so first i shall include the interrupt bit i have added this evening.

So i have added the connections for each bumper before the Setup.

const int RBump = 3; 

const int LBump = 2;  

two Ultrasonic sensors. would they conflict?

Im thinking of getting some ultrasonic sensors for my platform, to play with. I was thinking i would have one on the chassis, pointing forward for contact detection, and then one on a turret for mapping distances to plan a route.

Would the two get confused by each other?

I guess it would just mean you would need to make sure that they work seperatly, with a percievible delay inbetween using one sensor, then another?

or is it not an issue at all?