Archiving hint: In late summer 2023, Github started to enforce 2FA (Two Factor
                Authentication), so I had to archive it before losing control
                over it.  The heating radiator valve I operate with this 
                electronics and firmware works just as intended for 7 years now,
                so no inducement to change or further develop it.  See also
                #1

                Markus "Traumflug" Hitter, August 2023


ISTAtrol heating valve controller.

Designed for DIY-ability.

For documentation and pictures see http://reprap-diy.com/wiki/istatrol


This controller controls the valve of a heating radiator which is equipped
with a DC motor running at 3 volts. It comes with three temperature sensors:

  1) To be attached to or near to the ISTA counter.

  2) To be attached to the body of the valve.

  3) To measure room temperature.

User input comes in via USB and/or the included three buttons. Output drives
the DC motor of the valve. The motor of the first version was extraced from
a commercial digital valve controller and takes about 15 mA when running.
Valve motor as well as the MCU are fed by 5 V USB or alternatively by an
external voltage source (5 to 12 volts).

This controller was designed because these ISTA counters measure heating
consumption based on the temperature of the radiator, only, which leaves much
room for optimisation.


Directory contents:

  firmware/usbdrv:

    This is the V-USB driver stack. Unmodified extracted from the most recent
    distribution (2012-01-09 as of this writing)

  firmware/libs-device:

    Some helper files coming with V-USB, mostly unchanged.

  firmware/ (other)

    USB configuration, main application and Makefile. The Makefiles work well.
    "make" to just compile, "make program" to compile and upload the code. The
    bootloader Makefile has an additional target "make fuses" which sets the
    fuses correctly. So far, all programming requires an ISP programmer.

  Other files and directories:

    Electronic board design.


Markus "Traumflug" Hitter, March 2016