Recent content by Janne

  1. J

    Picaxe 28X2 200v 30A Mppt PV Controller

    Looks pretty nice. Did you consider going full synchronous buck? I've been pondering about that with a similar project of my own (wind mppt), seems like in addition to a normal half bridge driver it might need a reverse current cutout when dealing with a battery output. At least with standard...
  2. J

    Long Distance Serial Connection: Success!

    That got me thingking, if the programming actually is half duplex it might even work over an RS.485 connection and would just need 2 wires =)
  3. J

    Poor Man's (Electricity) Smart Meter... With new meters this HAN port is supposed to became more common.. If your meter has one it's quite an easy interface for getting data off the meter.
  4. J

    Setting multiple BITS more efficiently

    2 words, bitwise OR :) (and for clearing bits, bitwise AND with negate)
  5. J

    Monitoring the load on the National Grid with a PicAxe

    If you were here, you could actually get paid by the national grid operator for offering to shed load on your kettle :) .. In principle they offer money for agreeing to shed power loads in case of power shortage, with shortage being frequency dropping under 49.5Hz. Not sure how much they are...
  6. J

    PICAXE Floating Point

    That is pretty impressive.. I'm tempted to give a go at 64-bit floating point division math just to see how long it takes to run :)
  7. J

    Automotive ignition pulse sensor

    Hi, if it's recent enought to have an alternator, one and perhaps easier option would be to sense the engine's running state from the charging light.
  8. J

    Capability question - reading an RS485 bus while pushing results to PC

    Well you can even use the terminal on the picaxe editor if you want. The cheap RS-485 dongles have an USB to UART bridge built in, so once you've installed the driver you can open the COM port on any terminal you like.
  9. J

    Capability question - reading an RS485 bus while pushing results to PC

    Why do you need to put a picaxe in the middle if you just need to decode the protocol? USB-RS485 adapters are available for a few bucks on ebay. Once you've figured it out then implement what you want to achieve with a picaxe.
  10. J

    14M2 2-4 line LCD PCB

    Too dim on contrast usually means too low contrast voltage, so It's likely the LCD you're having would require a negative contrast voltage to work in 5V system. If you had a spare PWM pin (looks like you don't on that design) you could use it to generate a negative voltage with a charge pump...
  11. J

    Install axe 027 in Ubuntu 18.04

    Hi, Not sure how to do it in linux, I used a windows computer to do the PID change.. as per the instructions Technical posted in post #2.
  12. J

    Install axe 027 in Ubuntu 18.04

    Hi, from my experience the best method is to program the Picaxe usb lead with a PID of 6001, after that it's plug and play every time. Even if you manage to get it to work now, chances are the next version of ubuntu will have it work in a different way.. So far going up from 12.04, 14.04 broke...
  13. J

    Picaxe/Pi DataLogger

    Thanks for the info, I'll look into it. A word of caution about using the UART on PI, at least on some PI 3 B boards with bluetooth by default the UART pins on the 40-pin IO header are being run by the software uart, and the baudrate will go haywire if the CPU goes into reduced speed mode. Not...
  14. J

    Picaxe/Pi DataLogger

    Hi, Are you using some sort of x86 emulator to program picaxe from the raspberry? I'd be interested to hear your solution as I could use a raspberry-programmable picaxe myself. Or do you mean just collecting data from the picaxe to the raspberry using the serial interface?
  15. J

    USB data to FRAM

    µAL-FAT board might be the answer to this problem. Not sure about the current offerings, but the old boards they had could use spi or uart to access the file system on an SD card or USB memory.