Search results

  1. T

    Low Freq PWM and Interrupts

    You could use one of the AD9835 frequency generator units purposely designed for this task? Programmable from 1Hz to 25MHz. Once set to the programmed frequency they would then generate the 244Hz without further intervention.
  2. T

    closed loop DC motor speed control

    To throw another spanner into the mix... If the projector's lamp is not powered by DC, and also not LED or Compact Fluorescent, there may be some strobing generated by the "flicker" from the lamp. In a system where the motor and lamp are driven by the same AC source (possibly through a...
  3. T

    Download Circuit Question

    I've never failed to "recover" an AVR using a programming circuit that applies a 1MHz external clock. This can often be as simple as making the programming connections then applying the external clock to the required pins with flying leads held in place for the duration of programming. This has...
  4. T

    H-Bridge for 12V

    I've been using the L6206. Works from 8V to 50V, dual H-Bridge available in a Dil or SMD package and can be driven by PWM. It can also be paralleled for greater current capacity. DMOS output devices gives high current capability with low voltage drop. Integrated diodes and can very effectively...
  5. T

    What I Did with PICAXE During Lockdown

    Really well done. I hope you are super proud of that.
  6. T

    PicAxe Teaching System

    I recently bought a meter from AliExpress. It has a Li-Ion USB rechargeable battery, backlight LCD display, four digits readout, torch, hard rubber case, that is pretty much standard. What it does which amazes me is that it will automatically and seamlessly detect DC volts, AC volts and Ohms. I...
  7. T

    VS1053 Mp3 Module

    As I said in my earlier reply, I wasn't aware of the VS1053 supplying track info. I might have missed it, but did a fair amount of work before switching to the SPE035. There was a forum for developers of the VS1053 which was fairly informative. You can download a 'C' like development toolset...
  8. T

    VS1053 Mp3 Module

    I did some development on using this module before switching to the SPE035. I was attempting to control it in parallel mode though as I didn't (still don't) need track names. I wasn't aware that track names could be extracted. The version I used required the tracks to be arranged on the uSD by a...
  9. T

    axe133y oled display kit

    You don't seem to have removed the comment from line 12 which is required to *Define* OLED?
  10. T

    Water detect wire

    When my Elektor Weekly Newsletter arrived this morning, it pointed to an article that suggests a capacitive sensor using a 4060 counter divider where the capacitor for the oscillator is made up of two external copper tape "plates" positioned either side of a plastic pipe. As water reaches the...
  11. T

    zmpt101b Module

    For my Grid Frequency Meter I simply used the output of a (standard) low voltage transformer, half wave rectified the low voltage AC, sampled this a few times and stored only the peak reading, the peak reading was then multplied by a *factor* which was chosen to give the equivalent RMS value...
  12. T

    Hippy status, rev 2.0

    You are allowed to work part time. I worked two days a week for four months or so, paid "normally" by my employer for those days, paid partially by furlough for the other days. And of course there are VPNs. Still, I'm surprised, and more than a little worried by the ever increasing silence.
  13. T

    Hippy status, rev 2.0

    It is a little surprising that no new member has appeared on the forum, with a similar level of in depth knowledge and expertise of all things PicAxe with a user name of "Yppih". I thought that before being an official paid member of staff, a number of contributions to the PicAxe community were...
  14. T

    Code to control output On and Off pulse times with pots

    The code provided by AllyCat (Alan) above does much the same as my code. As mine is not in PicAxe BASIC, I see little point in posting it. The changes I would make would be to enclose the PWM generation commands in a loop that repeated a fixed number of times, then grab the pot values...
  15. T

    Code to control output On and Off pulse times with pots

    For the 555 circuit, I was thinking of something like this circuit. It should do 0-100% duty. If not, close to. I've used similar designs in a number of quick PWM projects, light dimmers and brushed motor speed controllers.
  16. T

    Code to control output On and Off pulse times with pots

    I designed a unit that generates a variable PWM at a variable (low) frequency for work (in a different dialect of BASIC). To get around the problem of leaving 'glitches' in the duty cycle and frequency I generate a fixed number of cycles, say 100, at the current parameters, read the values from...
  17. T

    Code to control output On and Off pulse times with pots

    For initial experimentation purposes, you could rig up a simple 555 timer. It is possible to use them to generate a variable frequency with adjustable PWM. As I recall, the frequency and PWM interact with one another a little but might be enough to prove your theory before moving on to something...
  18. T

    Turn on DFPlayer with 08M

    Are the speakers meant to be connected like that? I thought the audio out from the SPE035 was a bridge output, referencing it to earth could result in excess power consumption and possibly damage the amp on the SPE035. The speaker out is not left and right but a mono output with the speaker...
  19. T

    AXE300 Grove Displays

    Even sillier question, given that the LCD is mounted to the PCB at manufacture, we can perhaps assume that the contrast circuit is connected. Is the power supply correct? The datasheet for some of the modules suggest 5V, if the supply is incorrect, the contrast will be incorrect - especially if...
  20. T

    AXE300 Grove Displays

    Daft question, and I apologise in advance... Have you got the contrast control connected and adjusted? If you can see "something" it suggests they are working, but the contrast is too high or too low.
Top