I managed to sell this after I brought the price down... significantly. Unlike the AH 98 version, I did't feel so heart-pain. It was a mistake to buy this in the first place.
This edition is meant for Acquire game collectors.
Not bad, has electrical usage statistics too.
The product name is WiFiKIT-II-MRSLIM in Tuya IoT platform. Its version is 3.1.69.
add_ele and cur_power fields are not part of Standard Status Set, so they cannot be queried using Get Operation Log API — until you change the device from Standard Instruction mode to DP Instruction mode. These two fields are sent every 5 mins when in use. Other fields are sent on change only.
Now I'm finally able to achieve fan mode for 20 mins using Tap-and-Run scene.
I decided to buy the Spacemate WiFi module after all.
It is pretty small and light.
I cut myself when I removed the air-con FCU front case. It is always difficult if you have never done it before.
Starmex MSXY-FP is easy once you know the correct steps:
The CN105 port is not on the mainboard on MSXY-FP. It is at the IR receiver. I didn't know that and opened the mainboard cover unnecessarily. Short panic when I could not find the connector.
(This was mentioned in the Spacemate WiFi module installation video, but I didn't know what it meant at that time.)
I decided to run the cable out of the case. It should be possible to tape the module to the metal part and keep it hidden by the front cover.
The front cover can still be closed fully.
I find it tedious to set my Starmex air-con to fan mode for 20 mins after use. It's not that bad if I turn it off at a consistent time, but at any other time, I need to change the Off time, and this takes time — need to hold the left/right keys and watch the time inc/dec by 10 mins every 0.5s. If only the air-con has auto-fan mode, or a smarter Remote Control, or... WiFi.
Starmex does have WiFi, but it is rare and expensive ($200+ per FCU). Will need to use its app too.
A common workaround is to use a WiFi IR RC, but I want something that connects to the FCU directly.
I googled from time to time and this time, I found a third-party option!
There are two models: for Mitsubishi Electric and Daikin air-cons. Each model has two variants, one local Home Assistant only ($79), the other Tuya ($99).
And it is made by a local Singaporean! (No wonder he targets these two air-con models; they are the most popular models locally.)
It costs $109 on Lazada. It must be due to 'Lazada tax'...
$100 for each FCU is quite ex, though.
I was able to undertake this repair only very recently, after I acquired three pieces of information.
This Air Monitor is called PV28-CW. Once I knew its name, I was able to gather very limited information about it. Apparently people had been flashing their own firmware to it (with limited success)!
The first thing is how to take it apart. Apparently it is a common technique to hide screws behind the display cover.
Second is that a common failure for PM sensor is that its fan gets dislodged.
Third is that a dislodged fan can be put back! (If you can get to it.)
First step was to peel off the display cover. It turned out to be pretty simple.
I decided not to disconnect the flex cable since it was not needed to do so. No need to stress it.
Can see the CO2 sensor, PM sensor and battery. The battery is 3.7V 800 mAh. It seems a bit bloated. Now that I can open up the unit, maybe I can find a replacement for it. I checked the fan was indeed dislodged by poking it with a micro screwdriver through the air vents.
I tried to open the PM sensor directly, but found it impossible. I needed to remove the battery before I could peel the PM sensor off — both were taped to the PCB board. I checked that the PM sensor was not soldered on first. The CO2 sensor seemed to be soldered on.
Needed to pry open the top on all four sides. It was not difficult, just need a micro flathead screwdriver.
Opened! Next was to unscrew the fan. I had to use my smallest micro screwdriver.
I could only lift the fan up a bit. Luckily it was enough to fiddle with the fan blade.
Managed to push it in after some tries. It must have dislodged when I dropped the device from the bookshelf.
In working condition once again! (Battery is still flat.)
Will I be able to replace the battery and CO2 sensor?
I was not able to find a 1-to-1 replacement battery. It must exist, just need to search more. Higher capacity would be nice (*), but it won't fit in the space — around 5 cm.
(*) 800 mAh lasts around 4.5 hours, needs 4000 mAh (mobile phone battery capacity) to last a full day. It needs to be much more power efficient, a bigger battery won't help — I want battery life in terms of months.
I also could not find an identical CO2 sensor. There are very similar ones, but I don't know if they are drop-in replacement. Good news: a CO2 sensor costs around 40 - 50 yuan (~S$7.50).
The CO2 sensor is soldered on the PCB, it will take more effort to replace it.
At this point, the best scenario is to hope the CO2 sensor is merely blocked/dusty and a cleaning will unblock it. This is possible because a NDIR sensor is supposed to last for 5 to 15 years. I don't see any opening, though.
