Just bought one of these. I really like the form factor and build quality, but not the UI so I decided to look into making a custom driver for it. I’ve taken it completely apart and thought I’d share some details.
There are two PCBs, held together by 4 pins. The front PCB can be removed by desoldering the 4 pins and the LED connections. The back PCB is then held in by a threaded pill in the battery tube.
Back PCB:
The ICs at the bottom are the reverse polarity protection MOSFETs. This board is marked E7-B5.
On the other side is a boost converter:
Turns out I’m not yet allowed more than one image per post, so other images posted here: Index of /images/wuben-e7
It took me a while to figure this one out, but the boost converter is to provide a 5V supply on the USB-C port for the sensor accessory. I can’t find any details on the IC, but it appears to be a combined charge controller and boost regulator. When you supply 5V on what is normally the 5V output, it starts charging at up to 1A, and pin 3 shows the charge status (low = not charging, alternating = charging, high = fully charged).
Interestingly, this boost regulator is on all the time and accounts for pretty much all of the 0.1mA standby current. I presume this IC has a low-voltage cut-off, but i think it’s an interesting compromise to have an extra boost converter and a relatively high standby current to support an accessory which I suspect most people won’t use.
The boost converter means you can actually use the flashlight as a power bank for some devices - they have to be stupid devices that ignore the signal on the CC pins that indicates that the device is a current sink only.
The signal from the external sensor appears to be on the D+/D- pins, which are shorted together, so I’m guessing it’s a very simple high/low signal rather than any digital protocol.
The four pins that rise to the other PCB are GND, Battery +ve, charge status and sensor signal.
The front PCB is more straightforward. The front has an FMD microcontroller, switch, and 2 color LED. I’ve not identified the top left IC - possibly an op-amp?
The back has the driver. The IC is marked EABGdA, but I can’t find any info on it.
The inductors on the two boards are a tight fit once the boards are together.
I’m planning to make a custom driver to replace the top board. I might do the other one too to get rid of the silly standby current, but I’ve not been able to find a source for the USB C ports.