Recent content by premelec

  1. premelec

    PV Powered DC Pump Controller

    Thanks... I'm thinking of a drain back system which would allow fluid flow through pump when it is OFF and establish siphon when on.
  2. premelec

    PV Powered DC Pump Controller

    @mike thanks for the refs - I am impressed with the lack of data with regard to electrical inputs on small pumps - mostly just flow, head, temperature max. However a great variety of old style circulation models available at low price... empirical it is!
  3. premelec

    PV Powered DC Pump Controller

    Hi Mike, I'm curious about what pump you are using.. and thinking about the reliable start under low sun conditions... perhaps using current amplifier [switching down converter for soft start]. I have some salvaged thermal panels in my yard that I am thinking of running for DHW preheat... thanks...
  4. premelec

    PV Powered DC Pump Controller

    or time for a modest size ultracapacitor - I have zone valves that have worked for a decade which use ultracaps to shut when power is removed [Taco ESP] - I think they make higher voltage stacks now... or lithium battery string with BMS - I guess it could depend on how important starting in...
  5. premelec

    28x2 MPPT Success, 50v 35amp ,2.1Kw Panels

    @PiCaxeDB - very good project! Lots of hot water for sure... can you dump excess power into local grid? BTW one thing to check is rating of thermostatic switches for DC - AC ratings must be derated about 8x for DC to prevent arcing failures - I haven't heard of 48v heater elements so perhaps the...
  6. premelec

    Why can't I "make" a 3 pole 4 throw switch in basic

    "As a last resort, read the manual." - and hope that it is correct and complete and that you have time to make something after reading the whole thing... ;-0 [and make sure it is the latest version and you know what your chip version is... ]
  7. premelec

    Using a single cell LIPO to power an 8M2 or 14M2

    Look in Ebay for "USB Power Bank Case 18650 Battery Charger DIY Kit" - there are many varieties... usually holding one or 2 18650 cells; the key is that they are Do It Yourself "battery bank" units... have fun... If you want just the protection circuits rather than up converter part they are...
  8. premelec

    Picaxe Oscilloscope & Picaxe 28X2
  9. premelec

    BMP180 Code Examples

    Does this code work on BMP280 as well as BMP180? [BMP280 seems to have a bit better spec... ]
  10. premelec

    SPI ILI9341 LCD Display

    We all have our favorite platforms to do what we want to do - I still use mechanical switches and wires and discrete components as well as integrated wonders... note that dinosaurs lasted over 150 million years and we have been around about 1 million years... perhaps a better term could be used...
  11. premelec

    TOF10120 Laser Range Sensor Module

    We need programming esperanto! I guess it is just lucky that even more languages have not appeared...
  12. premelec

    A timing question

    Looks like we had the same basic idea for constant current to LED - I just used an op amp loop to control current from voltage set from a DAC that was PICAXE controlled [the DAC latches in and holds the digital] - the feedback being analog rather than back processed through the PICAXE AD...
  13. premelec

    A timing question

    FWIW note that LED brightness is better controlled with current rather than voltage.... an op amp and MOSFET converted a DAC to current output [I used 2 LM324s and 8 2N7000 in 8 channel DAC conversion units I made - serial from 08M2 to DAC].
  14. premelec

    Thoughts on adding additional I/O

    @Mark.R you can add varying an analog input to indicate various states to the list - IF you can stand the extra time to "see" and process an analog pin state. An example is reading a 12 button matrix with one pin. There are caveats... ;-0
  15. premelec

    Setting multiple BITS more efficiently

    Hi - what are the numbers of bits in b1?? ;-0 Clue... B0 is bit0 to bit7 ,,, b1 is bit8 to... From manual 2 In addition there are up to 32 individual bit variables (bit0, bit1 etc..). These bit variables can be used where you just require a single bit (0 or 1) storage capability. Bit variables...