Search for distance meters in Topics


Smart board Using distance meters.

Hello! My name is Muneer. I was wondering whether this concept of making a smart board would work(shown in image). The idea is to use two distance meters to measure distance ‘a’ and distance ‘b’ from the transmitter in the pen to the top corners. Distance c is fixed and known. Using the distances, the x and y distance should be workable from the formulas(shown in image) I guess. I have a few concerns and require your expert opinion, a. How can we construct the distance meter (IR? Ultrasonic? Any available schematic...etc) b. Converting the x and y distances to pixel information c. Interfacing the board to a computer, possibly giving the input from the smart board directly as a mouse input. or if you could suggest other practical ways. Could you please help me with this? Thanks.

Topic by muneersn    |  last reply


measure distance with raspberry pi?

How should i measure 10 meter distance very accurately with raspberry pi ?  if anyone knows any sensor that can measure distance of 10 meter accurately please tell me then i will manage ? thank you.

Question by dharmik123456    |  last reply


How to build a max distance alarm

I've been searching for an instructable that does that but couldn't find it. The basic idea is to put a small as possible tag to something(unpowered if possible) and have another small thing that can fit in your pocket. If the tag goes more than, say, 4,5 or 6 meters away your pocket box would warn you. I think its a great idea to protect from thieves but no idea on how could I build a device like that. Thanks

Topic by Saladino    |  last reply


Lens for FOCUSSING a 3 Watt LED upto 5 Meter Distance

I want to Lens to focus a 3 Watt LED for distance of 1 meter to 5 meter without diverging. The light must traverse as a beam upto distance of minimum 1 meter and maximum 5 meters.Can anyone suggest me the type of LENS and its details.

Question by aalishaan    |  last reply


Hows this circuit as mileage meter? Answered

I recently got permission from my parents to hack the car,so I thought,what mod is most suitable in India.so I came up with an idea of milage meter My dad told me that the amount of petrol used in each cycle of engine is the same,adjusted to optimum level. So I thought that if i can divide the rpm value with speed,i'll get rounds per distance,ie fuel consumption per distance. and i devised the following circuit for it-

Question by Suraj Grewal    |  last reply


Can magnet attract iron over longer distances like 1 meter?

Can magnet attract over longer distances like 1 meter if yes then how much powerful means in width , length , type of magnet do i need to attract 2kg of iron ball over a distance of 1 meter ?

Question by MuhammadK19    |  last reply


macePod - The procession project

Hi Art+Tech lovers Is it possible to track a simple object and calculate it's distance with an Arduino + (Arduino-)camera. I would use a simple tele lens so the distance between the camera and the object can range between 0.5 and 10 meters. The camera can be mounted on 2 servo motors for pan-tilt movement. Everything sits on top of a 2m pole, carried by a person.  And best wishes for 2016! Philippe

Topic by sysArt    |  last reply


Is it safe to look at a green 200mw Laser from a far distance? Answered

My laser is 200mw(MILLIWATTS), 532 nm(NANO METERS)

Question by GamingA9    |  last reply


Need a short distance range finder (<1m) that is 5v and puts out a 0-5v signal based on distance?

I'm trying to find a range finder that can measure distances less than 1 meter and puts out a 0-5v signal based on the range. It needs to refresh quickly and be accurate to +/- 2 cm. It is measuring distance to the ground which will be pretty flat. Thanks in advance for guidance. 

Question by LosV2    |  last reply


Calculating Speed?

If you have an object with a mass of 2000 grams, and it has an average force of 635.029 kg pushing it for a distance of 6.096 meters before it becomes a free-flying projectile.  How fast is the object traveling after the 6 meters and how do you calculate it.

Question by jj.inc    |  last reply


Sequential Lighting

I am looking to create a string of LED's that can be programed to turn on and off sequentially over 100 meters that can show the speed of a runner over that distance. ex: 100 meters in 9 seconds. any ideas, also re-program the same to different times.

Topic by ScottR148    |  last reply


fire launcher

Hey guys, i want something that can shoot fire up to a distance of about 2-5 meters so i can light bonfires and stuff easily, thanks for the help Pyro13

Topic by pyro13    |  last reply


how can i make a wireless power that can turn on a motor in a distance?

Hi every one,      i would like to know how can make a wireless power supply for at least  some meters so as to turn on my plane motor.

Question by waiswa martin    |  last reply


how to write specification for transmitter?

I trying to write specification for transmitter that transmit voice signal over 100 meter long at 97 mhz frequency modulation type Input voltage 12 v input current 9 mA input power output voltage output current output power operating frequency 92 - 97 Mhz oscillator circuit that generate 97 mhz frequency transmitting distance 100 meter long how to decide how much output voltage and current I need at output side ?  

Question by vead    |  last reply


How to make a robot car which automatically reverses its direction after going a certain distance?

I am using a DPDT switch, but have difficulty to decide what trigger to use.  I need to make the robot go 3 meters and the robot size itself is limited (15x15x15cm)

Question by Zellequeen    |  last reply


Paper Airplane Contest 4 (Closed)

Yes, I have decided to host another paper airplane mini-contest. My goal is to further stimulate the paper airplane channel and encourage more paper airplane builders to post their innovative designs. For this contest, the specification is for a long range plane. Requirements: 1. Aircraft Requirements: • Ability to fly at least 55 feet • Durability to fly at least 30 flights • Provisions for landing gear and/or skids (not required for flying wings) • Use of less than 11 inches (0.381 meters) of Scotch tape in construction • Use of less than 3 pieces of 8.5 by 11 inch (A4) paper in construction • Usage of glue or wood (excluding toothpicks) is prohibited 2. Instructables Requirements: • 1 page strictly devoted to materials required in construction • 1 page explaining how to fly the aircraft • The instructable's license must be: "Attribution Non-commercial Share Alike (by-nc-sa)" • This sentence and link must be displayed on your entry's intro page: “This instructable is an entry in Paper Airplane Contest 4 (https://www.instructables.com/community/Paper-Airplane-Contest-4/)." Prizes: For this contest I will award the publishers of the top 5 performing paper airplanes* one patch each. The first place winner will also receive a 3 month Pro membership. These patches will be medals (1st place, Patch with 1st Place Medal image and 3 month Pro membership; 2nd Place, Patch with 2nd Place Medal image; 3rd Place, Patch with 3rd Place Medal Image; 4th Place, Patch with 4th Place Medal image; 5th Place, Patch with 5th Place Medal image). *Multiple entries are allowed. To keep the distribution of patches wide however, each entrant can only win one prize. How To Enter: To enter this contest, you must send me a private message entitled “My Paper Airplane [Member Name Here]” with your instructable's URL included. I will then put the link and author's name onto a list on this topic under "Entries". Judging: For this contest, I have decided that I will judge all the planes myself based on abilities. I have decided this way because I believe judging on performance rather than shape is a more objective approach. The contest begins Friday, April 15, 2011 and ends Monday, May 16, 2011. Entries must be published before Monday, May 16, 2011. From May 16 to May 18, I will be judging all entries. I will announce the winners of the contest on Thursday, May 19, 2011 and issue them their prizes Friday, May 20, 2011. Entries:

Topic by OrigamiAirEnforcer    |  last reply


What is the strength of the other charge?

I need help with solving this problem in physics class. I know Coulombs equation F= k(q1q2)/r^2 The force between two charges is 2 newtons. The distance between the charges is 2 x 10 ^ -4 meters. If one of the charges is 3 x 10 ^ -6 C, What is the strength of the other charge?

Question by Baseball24_7    |  last reply


PC mouse Mod

I have always wanted to see my electrical usage in real time. However, the watt meters available can not handle whole house wattage. I have an idea but lack the programing skills to pull it off. Use a modified usb mouse to read the dial as it spins and tabulate the totals. Because of the distance through the glass to the meter disk- a laser pointer may have to be used. Required to work: USB mouse Modified mouse driver- must not be recognized as a mouse in the PC customizable display output. Laser pointer? Anyway, if someone could help with the software that would be great- Thanks

Topic by ryancey777    |  last reply


How to connect a 10 digit standard calculator display to a large LED display using minimum electronics?

I am interested to display the output from a 10 digit standard calculator on to a large LED display panel that can be read from a distance of 20 meters. I have found instructions in this site on how to make a LED Display pannel. I now need to know how to connect this pannel to the calculator.

Question by clarencepinto    |  last reply


HEY! I was trying to get 2 HC-SR04 to work together, such that i get the average of the 2 readings. but it doesnt work as expected and only displays 'OUT OF RANGE' on serial monitor. please help

This is my code:#define echo2 8#define trig2 9 #define LED1 2 // LED pin 2 #define echo 13 //ECHO pin 13 #define trig 10 //TRIG pin 10 float duration, distance, duration2, distance2, avg; //float command helps us to determine value of duration and distance in decimals void setup() { Serial.begin (9600); // setup ¯\_(ツ)_/¯ pinMode (echo, INPUT); pinMode (trig, OUTPUT); pinMode (LED1, OUTPUT);pinMode (echo2, INPUT);pinMode (trig2, OUTPUT);}void loop() { digitalWrite (LED1, LOW); digitalWrite (trig, LOW); digitalWrite (trig2, LOW); delayMicroseconds (2); digitalWrite (trig, HIGH); digitalWrite (trig2, HIGH); delayMicroseconds (10); digitalWrite (trig, LOW); digitalWrite (trig2, LOW);duration = pulseIn(echo ,HIGH); duration2 = pulseIn(echo2 , HIGH); distance = (duration/2) * 0.0343; distance2 = (duration2/2) * 0.0343; avg = (distance2/2 + distance/2); Serial.print ("Distance = "); if (avg>=400 || avg<=2) { // the formula of distance is duration of impulse divided by 2 multipled by speed of light in air meter per sec Serial.println ("OUT OF RANGE"); digitalWrite (LED1, HIGH); delay(50); digitalWrite(LED1,LOW); } else { Serial.print (avg); Serial.println("cm"); delay (150); } delay (150); }

Question by theHVguy    |  last reply


trigger retail door alarm

I know most people that think of retail exit door alarms want to avoid setting them off, but is there a way to purposely trigger them, especially from a distance? i am reasonably good with a soldering iron, ok using a ohm-meter and beginning on using oscilloscope. and i have lots of junk PC/PC parts and various other electronics around to strip for parts... (if that helps any). thank you for reading --rex

Topic by rexifelis    |  last reply


how to set wire router as wifi wireless resever?

I got problem to set wire as wifi wireless receiver should i connect it with axispoint to make it wireless , the router was made 2008 and how to set it as wireless reserve i want to use router due to the distance is long and my laptop is only 45 meter i just want to know does the wireless router could be wireless or just use the wireless one  

Question by zordrecon    |  last reply


remote detection persons?

Hello everybody, I live in a very remote area and am looking for a radio guided detection to see/hear when somebody enters my property. Distance from one place to the other minimum 700 meters. I have power but no telephone connecion, nor internet or mobile sources. A simple PIR detector that indicates that somebody (burglars, robbers) enters my private territory. will do; I am desperate after three burglaries. I look forward to any suggestions.  Thank you! Chaource

Question by chaource    |  last reply


Wi-Fi USB Adapter or PCI Wireless card

If i use a USB wifi adapter with a manual(hand made) antenna can it work like a PCI wireless card without and antenna.i want to connect to a wireless network (that provide wireless internet) that is in 350 meter distance to my home.i don't want to buy a PCI wireless card (because of it's cost).and want to use a manual antenna like this : Uni-Directional WIFI Range Extender that posted from tm36usa. thnaks very match.

Topic by sampro    |  last reply


Best wireless communication device for controlling 200 microcontrollers?

Heyo, I am looking for suggestions of wireless communication devices for microcontrollers (such as Arduino) to other microcontrollers(such as Arduinos). The distance will be about 100 meters, and I am looking for the most efficient and quickest way to send information from 1 transmitter microcontroller to about 200 receiver microcontrollers. I've browsed around and have some ideas of devices that can be used. I just wanted to ask other's ideas on the matter before I move on to testing my own ideas. Thanks!

Question by bigjohn412    |  last reply


What would be the best IR receiver for 980nm IR laser 0-15KHz

Dear enthusiasts, please help me out. What would be the best IR receiver to use for detecting signal from 980nm IR laser 0-15KHz. I'm going for distance here. 200 meters is more or less the goal. The further the better. Ambient light might also be an issue as this is to be done outside in possibly sunny conditions. If anybody has any ideas or suggestions please, throw them out here. Thanks.

Topic by GusevAnton    |  last reply


Yes. Back again, with more of a challenge. How would you construct a Gunshot-Location-System for 2006s standards? Answered

How'd you do it? The new requirements included: Shooter localization to plus or minus 15 degree accuracy, and within one second of the shot Reliability for shot miss distances of one to 30 meters Ability to detect and localize fire from AK-47s and other small arms at ranges from 50 to 150 meters Reliable performance in urban environments with low buildings Operable when mounted on a vehicle moving up to 60 miles per hour on either rough terrain or highways Ability to withstand sand, pebbles, rain, and light foliage impacts Ability to deliver alert information in both a voice announcement and on an LED display Microphone array and electronics box must be replaceable in the field[4]

Question by Lance Mt.    |  last reply


Track, Field, and Cross Country experiences

Hello everybody! This is knexsniper1 with a brand new forum for everyone to share their experiences! This time it's about athletics; cross country, track and field to be exact! In this forum, I would like everyone to share their experiences while competing, or just for fun; about the mentioned topics. you may share your fastest times in the 100 meter, farthest long jump, tallest high jump, but these are only some of the things that you can share. the choice is up to you! You can also use this forum for tips on competing, or you can share your ideas on how to compete better. Those of you who compete in these sports will have their name displayed here, and stats about them, such as their fastest times etc. Remember! I want this forum to be as "clean" and appropriate as possible, so don't be calling anyone a loser just because they can not run as fast as you, or jump as far as you, or anything! Just to start this forum off, I will be the first one to post my experiences on this! You may share anything you wish! some of my goals include competing national, and then moving on to international, beating the world record for high jump, and beating bolt at 100 meter! Have fun! knexsniper1: - 1 mile run: 5:27 - 100 meter: 10.62 Kiteman: -did an eight minute mile cross-country. That's a thirteen mile cross-country half marathon in less than an hour and three quarters. Smokedasphalt: -timings and distances: 100meters : 10.8s 200m : 22.1s Long jump : 7.08 meters. Triple jump : 13.76 meters. High jump : 1.80meters. Other achievements : Best athlete of the under-19 category of Pune city. Plus, loads of medals!! :D Now, I only concentrate on the 100m and long jump. Hope to participate in the internationals one day!

Topic by knexsniper1    |  last reply


Vibration comparison

I'm trying to compare two wildly different measurements, but I don't know enough about the physics of sound to even know what information I'm missing. I don't need exact numbers: some upper and lower limits would be fine, and perhaps even "back of the envelope" calculations in case the required information can't be found. I'd appreciate some advice on the formulas I need and what measurements am I still missing.  Object A is producing a sound whose intensity measures 25 dB at a distance of 1 meter.  This sound is, roughly speaking, a band-limited sawtooth wave with a fundamental frequency of about 35 Hz.  Object B is being driven up and down a distance of about 0.5 mm with an acceleration of 0.3 times that of gravity. The sound doing this is a sine wave with a frequency of 35 Hz. I'd like to compare the peak accelerations experienced by the two objects.

Question by CuriouserAndCuriousest    |  last reply


Send and receive an electric signal...? Answered

Hi everyone,I just wanted to know how I can send a small electric signal over a distance(not more than 10 meters)wirelessly and receive it at the other end to trigger a relay which in turn of course.. switch higher voltages and do something say...light a LED.I don't know much about frequencies,oscillators and FM/AM or anything.So please let me know how I can get an idea about these and most importantly accomplish what I just mentioned above.

Question by Adarsh_tronix    |  last reply


how much psi does galvanized steel hold, in compresed air?

Looking foward to making a spud gun out of metal, for high psi i know that pcv holds about 40-50 psi i want more bang for the buck EDIT¨: well i whas thinking of making a tube 1" gun of galvanised steel , pvc here is like $ 2-3 usd a tube that has like 2-3 meters, but i tought i could hold more psi in steel and there fore trow stuff  at long distance

Question by Bhakto    |  last reply


RF transmitted power Legality / Codes. Answered

I'd like to power some LED devices "remotely" using transmitted power. I've seen there are Instructables related to this www.instructables.com/id/Wireless-Power/ www.instructables.com/id/Wireless-Power-Transmission-Over-Short-Distances-U/ I'd like to create a power source that could energize a small LED circuit at a maximum distance of ~3 meters.  Even better, build an adaptive control, ensuring additional circuits are adequately powered, but design-limited to a safety max. My concern is to ensure the power source conforms to applicable United States regulations / codes.  I have a background in physics, but no experience in electrical engineering or contracting.  So I really don't know where to begin translating theory into device.  Can anyone suggest advice / guidance / starting references : What is the legality in the United states? Are there any codes that apply / regulate transmitted power? Pro tips? Muchas gracias for guidance and suggestions! CarLoz

Question by CrLz    |  last reply


how do you make a photon (or light) clock?

ok thanx to all the people that replied to my previous question about a rpm meter but now i have a new one. i need a way  of measuring the distortion of time inside the centrifuge and out side i have heard that the only way to do this is measuring the speed of light over a predetermined distance but i cannot find a way of duing this because light moves so fast and no processor i hav vome accros can do this so im asking how do i measure the speed of light.

Question by lj123456    |  last reply


Gravity Lamp Calculations

Http://www.core77.com/competitions/greenergadgets/projects/4306/ some people might recognize this little invention a while ago.  Well I recently wanted to make one after a freak snow storm rocked central pennsylvania (didn't have power for 2 days, it sucked balls).  But, after doing the math, his claims seem impossible.  Someone check the math for me: Facts of the Gravity lamp (with data in favor of the lamp_: output: 600 lumens weight falling: 50 pounds distance falling: 58 inches (in reality it's a bit shorter, but i'm just putting everything in favor) for ease of calculation and in favor of the lamp, assuming 100% efficiency. lasts for 4 hours calculations: 600 lumens = 7542 candellas = 7542000 mcd the highest efficient LEDs i could find output 120,000mcd at 20mA (0.02 amps) with a drop of 3.2 volts 7542000mcd/120000mcd = 63 LEDs 1 LED = 3.2 volts * 0.02 amps = 0.064 watts 63 LEDs = 4 watts 50 pounds = 22.68 kg on earth: the force of the weight is 22.68*9.8 = 222.264 newtons 58 inches = 1.47 meters 1 joule = 1 watt * 1 second = 1 newton * 1 meter 222.264 newtons * 1.47 meters = 326.73 joules 326.73 joules / 4 watts = 81 seconds, NOT 4 hours looking back at it, I think i messed up the calculations at earth's gravity, because that part is just totally wrong :P.  I'm not far enough into my physics class to know how to properly calculate that, could someone else?

Topic by guyfrom7up    |  last reply


What is the optimum solar cell sample size that I should select while testing it with PASAN SunSim 3B Sun Simulator?

I have to suggest sample sizes in order to generate some I-V curves using PASAN SunSim 3B Sun Simulator. The issues with the size and other things was about difference in distance to the light source, and the fact that the light source is not collimated and we can't collimate it, so we need to workout the tolerance. The distance between the external lamp and the sample is about 7 meters. External Lamp consists of 4 lamps connected to a single square shaped holder. The dimensions specs of the external lamp as given in the attached images. What if the sample size is smaller than the light source? What is the optimum solar cell sample size that I need to select? What parameters will be effects if the sample size is not optimized? "Please Keep In Mind That The Sample Size Should Be As Small As Possible". The attached images with help you in getting an idea, how the sun simulator looks like and what are the dimensions of external lamp

Question by raishikoh  


how do i amplify the radiofrequency of my 40mhz remote control so it will operate my receiver from a further distance? Answered

as some of you may know now, i am building an r/c tank, it operates on a frequency of 40mhz. now i have a problem, the old remote controller i had for it which i modified (by accident), has been thrown away after it stopped working (thanks to my un-understanding mother) the problem with this is though that i when i changed it around (i swaped some parts to make it work with aa's instead of button cells) it worked at 100m, the remote i have now though wont operate the receiver at any distance above 40 meters, so i want to know, where can i get a rf booster that will work for my remote control, sort of a thing that can boost the signal as it goes though the antena, or something, ive seen something like it in jaycars catalogue, but it only works on frequencies between 50mhz-1ghz, and it extends the radio coverage by 100m. since its only a toy remote i dont think it can be alterd, plus this one isnt the same as the chip transmitter i used to own, this one is a crystal remote controller.

Question by oldmanbeefjerky    |  last reply


Ir remote that activates 3 leds.

Hi, guys. I need some serious help. I need to build the following device: Remote control Ir transmitter with 3 buttons. Each button activates different led of different colours 1 button) red 2 button) blue 3 button) green A receiver device that acts in a different way for each button 1 button) red led lights for 3 seconds and there is a beep.  2 button) blue led turns on and turns off only after 5 minutes. 3 button) when third button on remote is pressed, then on a receiver device green light turns on, and turns off when the button is released. Also i need IR beam to be as thin as possible. On a distance of 1-10 meters its diameter must be something like 30cm. Is that possible?  Also how can i restrict IR beam to work only up to 10m distance. Also the problem is that i am restricted to 15$ budget, cause i need to build  60 pairs. If this is impossible for this budget i need the following: Remote control with 3 buttons. 2 buttons activates corresponding led for 3 seconds. third button activates third led only when pressed. The same thing with the IR beam diameter.

Topic by vnovick    |  last reply


How 2 build a simple model car wich runs on c02 produced by d reaction between vinegar n baking soda?bt there is a trick

Hi everyone!!..i hv tis competition cuming soon where we muz build a simple chemical car using cheap materials..d chemicals tad we muz use is 3 molar of 40 ml vinegar n 10 gram of baking soda...d car muz travel at least a distance 5 meters caryying a load of 100ml water ..bt d trick is,there muz NOT be  ANY spillage of water or sodium acetate which r also a by-product of d reaction otr ten co2...so any idea??all suggestions will be welcomed happily!!thx..=D

Question by artemis zoe    |  last reply


Calculating Drag When Firing Potato Launcher and Design Specifications

I'm interested in making a pneumatic potato launcher, I've found plenty information on that but I want to hit a target 255 meters away at an angle of 45 degrees. I calculated that I would need an initial velocity of approximately 50 m/s without wind resistance. The object being launched is an average sized potato under normal weather conditions. With wind resistance, what initial velocity will be required to hit the target? Please explain the process by which you came to the answer so that I may use the same method in future endeavors with different angles and distances. Also, just how much pressure would be required to launch a potato and achieve that speed, and to what specifications would the launcher need to be built i.e. how large the gas chamber will need to be, length of barrel, etc...

Topic by mike714    |  last reply


How can I make an rc signal repeater to extend rc toy range ?

I few week ago I bought a small rc car. Its receiver receives only a few meters away from the transmitter (approximately 3-4 m) . I like the car beacuse it's small however its range is too small. I thought that I could make some kind of a signal repeater or responder (I don't know which is more apropriate). That way I could but the "repeater" in some distance and be able to transmit farther.  So, can I make such a circuit? Also I thought that I could connect an rc transmitter with an rc receiver. That way everytime the receiver receives a signal it will activate the transmitter. Can I do that? P.S. Excuse me for my English I am new to the rc world :)

Question by christodouloskech    |  last reply


How should I make a webcam as a door camera and use it

I have a TV of aiwa model A1419 from past 25 yrs at home which I have not been using it since past 1-2 years and have not even started it because I bought a plasma TV 2 yrs back but my old TV even works fine till date if cable is plugged in. Now since I have this TV lying around and I also got a Lifecam Show & Lifecam HD 5000 webcams lying around I want to make a better use of it. So I would like to know how can I make them work as a security camera's outside my house door and watch anyone who comes at my door on the TV itself. The distance between my house door and the TV would be of at least 5-6 meters.

Topic by chandannasta    |  last reply


RFID - Metal blocking receiver issues?

Please can anyone advise? So we've built a prototype that detects when a bottle is opened And triggers a software response. We need to build the real thing next. The prototype: We've used a small passive UHF RFID tag mounted on the lid of the bottle, hidden under foil. When the bottle is opened this tag pops out and can be sensed. We have a long range RFID scanner that recognised the appearance of the tag and send the signal onwards. This currently works ok at a Distance of around two meters. Problems with the prototype: The action of revealing the tag is not very reliable. Currently we've just experimented with various pieces of tape and foil attached to the tag and bottle. We need to develop something reliable that could be applied to a couple of hundred bottles. The range is a bit shorter than we'd hoped as well - ideally we need the range to be over 5 meters. Our reader has the option of adding multiple aerials though which may help. And perhaps we could have a set of readers linked It's not necessary to use RFID if some other way of detecting when the bottle has been opened could be used instead. The reason we chose RFID is that the bottle doesn't need anything very large added to it. We are trying to sell these things after all. We really could do with someone who can help make this system more reliable Both by helping us with improving the mechanism for revealing the tag and increasing the RFID sensing range

Question by hanspan    |  last reply


Challenge - RFID reader + Wifi Module Low Cost.

Hi Guys,I'm an Oracle Architect and I have one customer that want to monitor water dispenser, he wants to know if water bottle was changed. I have a software to control it, but actually the people need to input this data manually and I would like one solution to do it automatically. I'm thinking to use RFID Reader on water dispenser and paste passive tag on water bottle and with this I'll receive the information and this data must to be send using wifi, I can't have cable in this solution (data and power cable is not possible). In my investigation, I just find rfid reader (UHF) able read a passive tag in 1 meters distance, the issue is, the UHF module is very expensive, I saw UHF module for 40 USD and I need something more cheaper. Is there another way to do it? I need suggestions and help to developer it.If need more info, send me email.Regards, Haysar Lelis

Topic by HaysarL    |  last reply


How To Build RFID walk Through Sensors (Stands)?

Hi All, I am planning to build an School Attendance System, RFID Walk Through Reader, So i need help from your end how can i built it (Step by Step Processs and Need of Material i need to use for it). My Planning: Need to built an RFID Walk Through Reader, means, suppose if a student ware an RFID Card in his neck and when he pass through from RFID Reader stand (it may be 3 meters distance between ID card and Reader) then automatically this RFID Stand will read the students information from his ID Card and send SMS to his Parents automatically. will you please send me Step by Step Process how to build it and what type of material i need and what type of Software i need to develop, etc...to my mail id: md.bismillakhan@gmail.com, i hope i can get my answer as soon as possible from your end. Thanks & Regards Bismillah khan

Question by bismilla    |  last reply


Help! photos, diagrams, etc required for Himmelstürmer

hello, I need some diagrams or sketches or photos of the german Himmelstürmer. If you have scale or measurements, that would be even better. one sounds like a simple enough device, and I would like to make it as a fun project. and post it up as an ible. all I know is that it consisted of two pulse jets and fuel tank(s). one small jet pointed down and was attached to the front of the user, the other larger one pointed at a downwards angle. fuel was stored on the front of the person. the engines did not run long enough to heat up, so there is no heat protection. it was used by throttling the engines, which would push the wearer into the air and forwards, allowing jumps of 60 meters distance and up to 50 feet height. I just need details of the, well, the entire device. the attached picture is just an artist impression of the device. I have no idea how to mount it to the user in a non-permanent way, and I need dimensions and such to allow it to be safe. I really don't want to make a device for an ible that could blow up the user. Thanks!

Topic by Nyanman    |  last reply


Wireless charging? Answered

So i would like to make a simple wireless charger for an ipod (ok ok its not so simple once you factor in the ipod) but i want it to be able to show a charging sign.... also it would be nice if it waould work from one or two feet apart minimum. I heard guys at MIT made one for a 60 watt lamp that worked 2 meters away... so its possible... i can probably order any circuitry if it is reasonably priced and available at digikey or mouser. :) I have access to several ipods so it doesnt really matter what model i use. I also know that this would probably make a huge electromagnetic wave... possibly? idk... but if it is big enough to destroy nearby electronics i might not want to try... So i am all for distance- the farther the better.... Also base power is not an issue, i can use a wall wart if i need to...i can just see an ipod touch with 500 passes of wire around it 5 feet away from a 2 foot square power station..... all while erasing my hard drive :) Soo.... im coming back to reality for a min.... anybody know any sites....any formulas too!! Thx! :) :)

Question by astroboy907    |  last reply


Simple AM transmitter

I wish to make an extremely small (size and part count) AM transmitter using only a few transistors and passive components. I wish to transmit an audible tone on a set frequency.I am thinking along the lines of a transistor flip-flop circuit oscillator, perhaps routed through another. It really needs to have less that five/six small components. DIP components are too big. Small electrolytic and other capacitors, transistors, and resistors are acceptable. Transmission distance needs to be at least 1/4 of a meter, but further is better. It needs to run on between 1.5 and 6 volts, low to middle'in milli-ampage im thinking watch batteries for a few hours at least. I have read the following article but as stated before it needs to be very small. https://www.instructables.com/id/Make-a-simple-AM-transmitter/Can anyone help me out with a schematic, thoughts or advice?Thanks in advance,-AndyP.s. I can work out transistor loop timings and I understand how the Amplitude Modulation system works. Current thoughts/plans (if you can call them that) are an audible tone switching a secondary transistor loop from high (no resistor in series) to low (resistor in series) power and back. The secondry loop will be switching at the target frequency.

Topic by andy    |  last reply


Bluetooth vs Radio Frequency Answered

This is a 3 part question: 1. I am a bit confused. Radio frequency covers 3KHz to 300GHz, so it basically includes bluetooth(2.4 GHz). Why is it that some people talk about bluetooth as something not relating to RF. Do they have different transmission methods? WIFI is also @ 2.4GHZ. What is the distinction between WIFI and bluetooth that makes them so different, covering different ranges, and being able to send different amounts of data at different speeds. I always thought it was the frequency of the wave but WIFI and bluetooth are the same yet they are so different.  2. I am building a project. I need to send data wirelessly. The data is very simple just to turn on or off a series of leds. A friend of mine told me to use radio waves. What does he mean by that exactly since radio range is huge. Is he talking about 40MHz like the RC cars? 3.Bluetooth or RF(again im assuming this to be the same one as RC cars since i will break apart an RC car to remove the transmitter/receiver)Which method consumes less power to send the same amount of data. Distance will not be over 10 meters so i'm not worried about that.  Thanks for the help everyone, much appreciated! Chris

Question by Chris414    |  last reply


Long Range Lidar Using Arduino

Wondering what the best solution for a long-range lidar setup would be using Arduino. I see that there was a similar question about 10 years ago, but seeing as the sensors/meters available have greatly improved since then, i was hoping to get some insight from people with a good deal more understanding of the issue.(NOTE: Apologies for how long this is, but figure i would try to save anyone who is kind enough to answer this, the time of having to ask what the specs are...)Description:Can assume clear day, so i would assume something using higher frequency light would be more ideal, but again open to whatever suggestions make sense.Range is more like that of a boat radar, so upwards of 1km would be great, but anything above 100m would probably work. And would need it to have enough detail to say separate out leaves from tree trunk for anything under say 40m, and past that it can get less accurate if that helps make it easier to setup. 180-360 degrees measurement. If i have to build my own servo to rotate a range finder that has the distance/accuracy that isn't likely a problem.Ideal would mountable on a moving car, similar in many ways to existing lidar for vehicles. (I am not sure if those are sold on the market, and could be used and hooked up to a pc, etc to record the data already? If so that might be the answer i want, depending on price.)Student budget, so cheaper is preferred. Willing to do some programming, etc to get it work with lower cost.I need to send the output back to a pc/tablet/phone to record the data which will be used for a vfx project I am working on. And i will likely need a reading every second or less, ideally, 24 or 30 frames per second would be awesome. I can do the coding if all i am getting is a bunch of distances/angles/etc to store it, just as long as the sensor can scan fast enough for instance if i have to attach it to a servo, can i spin it fast enough to get that kind of data coming down the pipe to the Arduino or pc, etc.That's pretty much the requirements. Curious what the large brains out there will say as they smack me down for being naive, which i have no doubt this project is....My general feeling is that going with camera distance seems both not accurate enough at that distance without using a super expensive set of cameras, and also would require a good deal of software to get working, say if you are comparing to camera feeds, in realtime etc. I don't imagine I could get whatever Elon has in his Tesla's for instance, wonder how good their distance calculations are. So it seems to me this is likely a case for some electromagnetic emitter/sensor and possible using amplitude modulation, but I am not even sure there are sensors out there that can detect such accuracy. I am curious if radar is not able to get the detail I was hoping for, and that is why lidar systems are used for grabbing details for movie sets etc, though doesn't radar go down to 1mm length waves? Not sure what freq say a boat radar uses? I guess, also, I want to avoid sending any waves out that I am not suppose to, not even sure what the requirements/restrictions are around that? I imagine lidar is fine because it is just light, so that is all ok, but radar might be I guess an issue anyway if you are sending it out past 100m for instance? I know boats do it, but not sure what freq, and whether it is ok to drive around with it on a car for instance? I don't want to break any laws that way either, so yea, guess i will have to look that up. I might be way over my head, but figure worst I can do it be told that. I am new to this subject, but I do have a degree in math so coding/math doesn't scare me, but the rest, Arduino, etc I have only really had a bit of experience helping code ardruino's for my friends projects, but never setup one from scratch. Thanks for any help!

Question by Elliot7777    |  last reply


What do you think about this dish as a WiFi signal booster? Answered

Hello everybody, I am in the process of setting up wireless internet at home, but am still a complete novice in this field. I have just bought a ZyXEL G-202 USB wireless adapter and I am making an antenna of sorts following some instructables as we speak. On my laptop I usually get 1-2 stripes at most when it comes to signal strength, so I was planning to do some piggybacking with my desktop. :) (hey, internet is not cheap here in the Balkans. :P) Anyway, I live in the capital where we have many Cafes and institutions providing free wireless, so why not make the most of it, it's not illegal here. :) The only problem is, I live in an block of flats; so many surrounding buildings tend to block and corrupt the signal. For instance, in my room (using an Acer laptop with built-in wireless) I get a list of 5-6 free (read: unsecured) APs, but the signal is so weak, it's good for nothing. :( Now, having examined my options, I was planning to make an antenna and put it on the roof of the building. But, when I climbed to the top, I found this old abandoned satellite dish SEE PHOTO (I asked around the building and nobody knows who it belongs to. Additionally, it's very run down as you can see, and the cables are torn out, so I was planning on claiming it. :p). Now, my questions are: 1. Can anyone tell me if it's a good idea to use this dish as an antenna, if I weather proof my USB receiver and mount it on the focal point of the dish? (Line of sight (aerial) distance from it to the nearest free wifi hotspot is approx. 600 meters) 2. Is there a possibility that my USB will get too hot, maybe catch fire, because of the signal boost? (Maybe this is a dumb question, but I really don't know much about these things) 3. Finally, I would also need an advice in regard to the cables needed. I already downloaded the "How to extend your USB using UTP" instructable, but since the cable should be about 60 meters long, is there a way to make it not loose too much signal? Thank you all for reading this, and thank you in advance for your advice. Any type of help is welcomed. :)

Question by Kandid    |  last reply