I need this project details : Assume that your photo diode is connected with Micro-controller (any) and micro-controller o/p is displayed in 16*2 LCD. Write a program in Arduino IDE for measuring light response of photo-diode into voltage, absorbance and transmittance. Display these parameters in LCD.

Topic by AyushJ39   |  last reply

Photodiode help?

I bought a photodiode (not really knowing what it was) and I don't undersand how and where to use it. I tried it as a light switch but it seems to pass electricity through it in both in light and in dark 

Question by or_ford98   |  last reply

Help with photodiode?

Hii i am working on a circuit where i want to use photo diode as a switch.. that is when infra red radiation falls on the photo diode, it will allow the current to flow through the remaining circuit. but when i did the circuit, there was a small problem. even if ir led is not used, small current is passing through the remaining circuit. how can i stop this. how can i make it in such a way that no current will flow through the photo diode unless ir rays are allowed to fall on the photo diode... thanks in advance..

Question by allsparkunleashed   |  last reply

Photodiode as solar battery

Hello!I'm trying to build "Solarsound modules" However, it is quite hard to decide what to use to drain power from light - the device has to be small and give 2.5V. Are photodiodes suitable for that, or do I have to buy a solar panel? What PD or a series of them would be the cheapest solution?Thanks a lot.

Topic by wasia1   |  last reply

Hacking Flatbed Scanner Components

I am currently working on a project which was going to use a scanner to acquire an image. The scanner is/was an HP 6200C. When I was trying to modify the scanner I accidentally broke the lamp, but was then excited to discover [what I believe is] a linear photodiode array which functioned as the detector. (I also found some cool mirrors and a focusing lens inside.) This photodiode array could be very useful to my project.  This scanner interfaces with my computer through USB, and refused to work after I unplugged the lamp. I figure a resistor may trick the circuitry into thinking the lamp is still attached, but I no longer require the moving parts of the scanner at all; I only want the photodiode array and a way for it to interface with the computer, preferably giving either a "single line" type image or a "single really thick line" type image. (Basically I just need intensity and location of signal. If the received data is a full image, I can reduce it to what I need.) Does anyone have any experience or suggestions for me? I have uploaded a few pictures of the relevant circuitry and can add more upon request. Update: After further research, I've determined that it is not a photodiode array but a linear CCD.

Topic by rogers236   |  last reply

can i use tv remote sensor in place of photodiode in proximity sensor circuit? if yes please tell me how

Can i use tv remote sensor in place of photodiode in proximity sensor circuit? if yes please tell me how

Topic by MukulB8   |  last reply

Find the average and highest voltage from multiple photodiodes before analogue Arduino input? Answered

Hi, I have a large number of photodiodes (too many to connect all of them individually to the analogue inputs on my Arduino) so I was hoping I could form say 4 groups each containing several parallel photodiodes and find the average the highest voltage for each group. This way each group uses 2 analogue inputs. The picture below depicts one group of photodiodes connected to two 'black boxes'. The 'highest voltage' black box would determine which input had the highest voltage and would then output that voltage to the Arduino. The 'average voltage' black box would average the input voltages and output this voltage to the Arduino. I have found a passive averager circuit on this website - - which appears to be suitable however I have no idea how to find and output the highest voltage. Hopefully this sufficiently explains what I'm looking to do and I look forward to getting feedback. Andrew

Question by Andycb93   |  last reply

Design idea help needed- nightvision

Is it possible to create a night vision with the following circuit... fitted with scanning disk tv method (accept for the fact that i'll use multiple mirrors instead of disk with holes) of video capture and display. Will it be sensitive enough? what I plan to do is- In simple terms, ill be using atmega as ADC... and photodiode as signal input. output will be via port d... if value of input is 1, one led red is turned on.. if value is 2,one green led red is turned on.. if value is 3,1 red and 1 green if 4=blue if 8, 2 reds 9, 3 reds so on

Topic by Suraj Grewal   |  last reply

What are these? Answered

I came across about 100 of these, I am not sure if they are photodiodes or LEDs would like to use them for something!  Have tried them at alot of different voltages, they all have a resistor inline with them which makes me think they are LEDs not sure on operating voltage. they also have a glass lens. markings - mexico 1150

Question by mutantpoptart   |  last reply

can laser be used as a frequency source for a photodiode which can act as a transmitter/oscillator? Answered

Photodiode induce current when a light of paricular wavelenth/frequency  strikes on them..laser have a high frequency and low wavelenth......instead of light but electromagnetic waves,can it act as a source of frequency on photodiode hence making a oscillator????

Question by arihant   |  last reply

how can i make a simple circuit with this photodiode?

I want to make a simple circuit and not a arduino powered robot.

Question by Tawhid K   |  last reply

Could a phototransistor be used to trigger a somewhat high voltage capacitor discharge? Answered

Or would it require a secondary switching mechanism?  I am trying to build a light trigger circuit that is as simple as possible.  I have an idea to use an ir led across from an ir phototransistor  and have it trigger when the light is blocked.  I need it to run 450v through.  is there a phototransistor that can do this and if not what might be a better idea? Edit:  This is to trigger a secondary acceleration coil in a coilgun.  I am leery of using a relay for it because i don't know if that will cause too much of a delay.

Question by finfan7   |  last reply

how can i tell the difference between phototransistors, photodiodes, and ir leds? Answered

i have a bunch of ir leds, phototransistors, photodiodes and things i desoldered that are probably light sensors of some kind. is there an easy way to test what they are without destroying them?

Question by the judge   |  last reply

IR iPod universal remote Help ~ I need help with the diagram!!!!!!!!!!!

I am trying to build an IR iPod Remote. This device will be able to send an IR signal to your TV and control it. The device will connect to the audio jack. I have shown a driagram of this. However, I need help in creating a device that i will plug into my mic jack and record the signals from my TV remote. ( I have a IR photodiode, IR LEDS and a IR phototrasistor. ) PLEASE HELP ME!!!!

Question by VHawk   |  last reply

how to make the photo diode that detect light , to convert it to image?

I want to know how to use a photodiode to detect a light and converting it to an image

Question by Ask Alice   |  last reply


The Electronic Goldmine  has a rare to find component. "Tiny audio optocoupler is about the size of a pencil eraser and has 4 leads. These are used extensively in audio compressors, audio level controls, audio limiters, expanders/noise gates, guitar tremolo effects, guitar amplifiers and music effect boxes. Inside the black epoxy case is a 2 lead photocell (not a photodiode or photo-transistor) and a 2 lead LED. This is why the device finds extensive use in audio applications (photocell instead of photodiode). The LED requires about 10-16mA current and the resistance of the photocell varies from 150K up to megohms when the LED is off to under 400ohms when the LED is on." A

Topic by iceng   |  last reply


I am trying to use a phototransistor to detect an object passing between the diode and transistor.  The problem I am having is that the PT is always on - even without the photodiode.  Are these things that sensitive that even a florescent light will trigger it?  If so, how do you prevent it from staying on?  I have never used these things before and my electronic design is pretty limited. TIA, Les...

Topic by les dale   |  last reply

Can I convert a 220v day night switch to 12 v?

I've got a light sensor switch that requires a 220v input Is it possible to concert it to work on a solar system? Sensor-Photodiode Switch-E.M. Relay Supply- 198-264 V.A.C Typical load- 2X250W H.P.S Maximum capacity-5A/60uF On/off levels- 70/105 LUX (1:1.5+VE) Part number- F3131D

Question by fjchorn 

How can i make a a 220v day night switch work of 12v?

I've got a 220v light sensor switch that i want to mount on a solar light, Sensor- Photodiode Switch- E.M. Relay Supply-198-264 V.A.C Typical load- 5A/60uF On/Off Levels-70/105 LUX (1:1.5+VE) Part number-F3131D Is it possible to convert it to work on a 12v system?

Question by fjchorn 

pinout help for my salvaged ir sensor/photo diode from mouse.?

I have salvaged ir emitter sensor pair from an old optical mouse. ir led glows fine on testing with mutimeter but the sensor part has 3 legs and i have always worked with 2 leged photodiodes . what is this specifically called? how can i know its pinout by testing with multimeter?

Question by Atul009   |  last reply

Can i start a motor with an IR LED?

Hello, i'm new to electronics and I know just a few basic things. I'm trying to make a simple circuit that goes like this: I want to have a sort of remote : 9v battery + resistor + ir led (i've done this part) And a reciever that starts a motor when i point the ir led to it. What components do i need to make the motor start when i point the led to it? Searching the internet i found i can do it with photodiodes or phototranzistors but i couldn't find the exact schematic for the circuit. Does anyone know how to do it?

Question by agent4ever2   |  last reply

Looking for an Electrical Engineer to partner with

Hi - I've got a business idea that requires hardware and I can't build the thing myself.  I'll write the software for it, but I need assistance building the circuitry. The circuitry involved would include a temp sensor, R/F communications module, photodiode, memory (possibly micro SD), controller,  and a timer in a very small form factor (about the size of a cigar tube). I'll split any profits from selling the device 50/50 with the HW designer.  I'll ask you to sign an NDA before we get going. Please contact me here or at bret at thelastmilellc dot com. Rgds, Bret

Topic by bschuhma   |  last reply

Pinout for disposable SpO2 monitor (Masimo LNCS Adtx)? Answered

When I was in the hospital recently, they used a "disposable" blood oxygenation (SpO2) fingertip monitor. They let me take it home with me afterward (otherwise they'd just discard it!). I would like to find a pinout for it and see what else I can do with a paired LED/photodiode.The model is Masimo LNCS Adtx. The connector is rectangular, but with a "9-pin D" style of pins -- top row five, bottom row 4, and with the second pin in each row removed for keyed insertion.I've been able to find operator's manuals and user guides on the Web, but nothing technical. Anyone out there with medical equipment experience who can point me toward a spec?

Question by kelseymh   |  last reply

I have a LED i cant light, no matter what. It has a little black dot in it. What kind of LED is that? Answered

Appearance: It is a common 5mm, transparent case, LED, being different from all others only by having this very tiny square dot over its anvil, kind of covering the reflexive cavity where the semiconductor (i don't know which) gets lit up. Other: I could not light this LED whit voltages from 1.5V to 3.5V. =O It came out of a photocopying machine, and was paired with an IR LED in some kind of emitter-receiver set. Other components of this set were a pair of smd resistors and a smd trim pot. Would it be and IR receiver or photodiode? UPDATE: I've took some photos of the mysterious LED. BUT, as no macro-enabled camera was available, i had to do the ghetto-way of photography. Soo: i have photos of it compared to the IR LED, and some photos of both anvils (IR, unknown), at 200x magnifying. Here they are. BTW, i hadn't tested the suggested circuits yet. =(

Question by vinacarv   |  last reply

Building a liquid monitor box help

Hello. I have little experience with these things so I am seeking help here. I have a prototype design for a liquid drop monitor. There is a tube that drip liquid and be detected by a photodiode hooked up to an Arduino. My question is about how to build an enclosure for it subject to my requirements. If anyone has advice for any of my needs below, the help would be much appreciated. I am not very knowledgeable of these kind of things. The circuit is in in two parts on two small breadboards, the detector on one side and an LED on the other. A tube will go through the box vertically from top to bottom. The box will be made out of acrylic because it's cheap, see-through, and I have access to a laser cutter. First question, how can I mount these breadboards in the acrylic box in such a way that I can remove them when needed or later replace them with a PCB later. Second, what sort of mechanical device can I use to adjust the distance between the LED and the detector? Essentially, I just need to be able to move the LED towards and away from the detector in one dimension. Third, I will need to change out the tube often to adjust the thickness. How could I allow for adjustable sizes? If the tube hole is the same size then I will only be able to fit one. Alternately, I could move the detector and LED horizontally to select different tubes. Is there a mechanical device for this? Fourth, I'm using acrylic because it's cheap and I have access to a laser cutter, but most designs for boxes I've seen are not made to be opened. I will need to be removing and rewiring things often. So is there a common or easy way of making/mounting a hinged acrylic door or a removable top? I apologize for the simplicity of my questions, but I really could use the help. Thanks!

Topic by ballaw   |  last reply