Search results

The simulator is using the generic value setting for my ADC input. I have other analogue inputs to and changing these values on the simulator doesn't do anything. Have I missed a configuration setup or something?

I am building a wire guided robot. I have a transmitter based on an oscillator currently running at 80kHz on the wire. With suitable choice of coil & cap and inc my oscillator to 150Khz or greater can I use the MK484 radio Ic chip to tune into the signal in the wire, amplify it using a...

Can anyone recommend a cheapish video cam & trans suitable for monitoring garden critters at night or in darkness (possums, birds, hedghogs etc) I'm assuming the trans signal could just be tuned in on a TV or PC TV card.

My picaxe project is a robot lawnmower. In undesirable situations such as tilting of the mower I have failsafe hardwired a relay to disconnect the power to the cutter motor (12V up to 100W) and connect the motor to GND in order to brake it in the shortest possible time. A manual switch (reset)...

My next project is to buid a battery charger. I want to use an 08 and make a smart charger. Does anyone have any info or resources on how to charge a gel battery. I know that I need to bulk charge to about 80% battery cap (10.8v), then switch to constant current until charged (13.5V) and then...

I have built a PWM drive with a 555 and an op amp. The output from the op amp drives a trans which drives an n channel mosfet. I have the emitter of the trans oscillating, so the pwm is working and I can see the duty cycle changing as I tweak a pot. But the motor isn't changing speed. I...

I want to produce an analogue output from a picaxe to replace the signal from a pot which is an input to a comparator (or controls an astable 555) Does the frequency matter and how do I decide the values of the Cap and Res? Can someone give me a starter to begin experimenting.

I have a 4N25 optocoupler and I want to use the PWM function of the picaxe to drive it. The 4N25 would be switching an IRF 530 supplying a largish motor (24V 5A). How do I work out if the 4n25 can switch fast enough. All I can find on the datasheet is the non saturated turn on/off time. This is...

I am trying to measure the current draw of my robot to size the battery pack. I currently have 2 x 12v Pb acids in series. I put the MM in series just after the +ve terminal so I can see what current the 3 motors are drawing. When I put the MM in the circuit it says 4 Amps which is about right...

I have an intermittent problem. I have a transmitter powered with 2 AA cells. It transmits temperature and the battery voltage as measured by an analogue input once a minute. The batteries are actually giving 4.9V so I set a software alarm threshold of 4.5V to tell me when the batteries are...

Getting very frustrated with my first robot project. I've got the controller working on a breadboard but am having a great deal of difficulty with the selection of drive motors. Can anyone walk me through the process. I have bought motors which are not up to the job and it's going to be...

I have the rev ed retailed Honeywell sensor and it is giving me up to 122% Humidity readings. Power is 3 x AA cells, actually giving 4.92V. Here are my calcs, I'm sure they are OK but at full 10 bit ADC (1023) it will allow the sensor to indicate 135% RH. Any one else have this problem? VOut =...

Do I need to use special wire or a proper aerial for these devices. At the moment I am just using some hook up wire and it's working with the rx sitting under my desk on top of the PC case and the tx about 10 m away outside. If I have the tx close to the house, kind of in a corner the reception...

Any tips on this? I'm used to just drilling a few holes in a plastic box and I think I'm going to make dog's breakfast of cutting the hole for the Axe033 LCD module It's a tribute to Picaxe, before this I could only dream of using an LCD in my projects.

Has anyone done this? Did a search but couldn't find anything. I have an 18x transmitting temp and humidity measurements on the bench and have just come to design the power supply and thought why not go solar. Can I just have a panel charging a small 9 or 12V re-chargable battery (through...

I have a few dollars and thought I would upgrade my DMM. My old one is a basic cheapie, std, ac/dc volts, resistance and diode, not even current measurement. The advent of Picaxe has accelerated my need to understand what's actually going on instead of just bolting it together and the light...

This is picaxe related in the sense I am interfacing this circuit to a picaxe http://www.electronics-lab.com/projects/science/006/ my circuit doesn't include the meter. The output of the amp is rectified and fed to a comparator which is connected to the picaxe. When I use the multimeter on...

I am using an op amp on a 9V supply as a comparator. I want to connect the output of the op amp to the picaxe input so have thought of using a 5.1V zener diode across the output and 0V. Can I connect the output of the op amp in this arrangement to the picaxe input without any problems? Do I...

I have just come across a strange one. I have program which starts off by sounding a buzzer for 5s. It's worked fine for a month. Now when the board is not connected to the PC ie 4.5V battery pack or 9V supply (but not simultaneously!) the program hangs and the buzzer sounds continuously. On...

Guys, I am building a wire following robot. I have successfully detected a 5KHz signal in a wire using an op amp in a detector circuit. I'm now stuck. How do I make this signal suitable for a Picaxe input. I will have 2 or 3 sensors ultimately and need to have the picaxe know the signal...