The one you did (009?) Is the newest wirh the most features and without the authenticating. Now, the older models didn't have the sensor, so while not as precise, you can enjoy the newer features and still use diy.
I actually have two of them. My original one is just a monitor unit running 9.16x and my second one is running 9.3r31. My old one needs repaired now and was planning on sending it to Alex for service but am concerned a firmware update will keep me from using my own reagent.
Hanna HI70464 1.0N reagent grade HCl costs $US 32.00
I have done all the upgrades my self over the years. I contacted Alex and he said he just charges for the parts that were needed so I figured what the heck. I dont know about everyones khg but I test my alk with my red sea kit every other week or so and most of the time I need to reset the reference and I sure would never trust mine to dose alk. I mainly use mine to watch trends for something going wrong.
Right I have that down. How do I install the previous version without bricking my unit?
Reverse engineering software is time intensive, can be frustrating, but it is doable.
My khg's are really basic from what I can tell. they have a precise needle for the droplet size and a sensor to count the drops. Adds drops till it reaches its goal ph level then calculates the alk determined my the number of drops. I guess the drop count could be affected by the weight of the reagent which could cause the drops to be smaller or larger but that would seem to be very minuscule. I dont see anything that would be used to tell the reagent composition to know if it is diy or oem reagent. I may be way off in my thinking and stand to be corrected.
I would love it.Had to dig around my old things to find this,
but here's an example of a payload I injected a while ago into a dosing pump made by Jebao that had a bug where it'd fail to properly load settings after power cycling.
This payload was used mainly to debug the problem itself, and once I figured out what was going on, I was able to develop a patch for it to permanently fix their own bug, which eventually required just a small modification of 2 function calls (marked in red is the actual patch, the code around it is what applies it to the firmware).
It took me about a week (in free time) from start to finish to tinker with and figure it out, however - I had the device on hand, had rich familiarity with its architecture instruction set and their firmware used some open source software that I was able to recognize and thus did not have to fully reverse engineer, which made this process easier for me.
The KHG from the quick glance I had in its firmware, is based on an architecture I have less experience with, and I also have no physical device to facilitate a proper debugging environment to work with.
Having a device on hand (preferably a locked one) would be the biggest road block here IMO.
Anyway - my point is that it is possible and practical to achieve, it'll be fun to work on, useful for many and most importantly - show prove companies that these practices are wrong and will get bypassed.
If someone could pop the back off a unit and take a photo of any leds/sensors in the reagent path, and any markings on them, the sensor type could be determined.
