Recent content by Kiwi Bruv

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...