While uploading sketches to the MM mainboard double + function board ESP32WIFI, with either the MM ESP32 or the MM Artemis is working without any problems I did notice something weird today.
The charge led is flashing unregular all the time with the MM ESP32 processor
Situation :
ESP32 WIFI function board in place
No battery or LIPO connected.
Power jumpers are in the default place. (both right)
Charge switches in the default position (both on)
Measurement with analog logic analyzer (Saleae logic 8). The measured voltages are shown to be stable (< 0.05V noise)
With MM ESP32
5v -> 4,825V (after the PTC)
3v3 -> 3.229V (on MEAS connector)
The charge led is flashing unregular all the time. Even when I push and hold reset it flashes unregular but much slower.
When I connect a probe to the battery '+' connector, it stops flashing, Charge LED is off. I have different probes and depending on the probe the '+ 'will read 0V or 4.165V. Probably an impedance issue.
[b]Changing over to the MM Artemis[/b]
All seems normal when installing a MM Artemis.
5v -> 4,877V (after the PTC)
3v3 -> 3.239V (on MEAS connector)
The charge led is OFF, seems to flash sporadically, and always flashes shortly when I touch the '+' on the battery connector. This is to be expected and measure 0V.
Alternatives I tried with the MM ESP32 processor board
1. Remove the ESP32 function board.
5v -> 4.945V (after the PTC)
3v3 -> 3.294V (on MEAS connector)
The charge led stays OFF.
2. Standard situation, but both charge current resistor off .
5v -> 4.907V (after the PTC)
3v3 -> 3.294V (on MEAS connector)
The charge led stays OFF.
3. Standard situation, but only the 100mA charge current resistor ON .
5v -> 4.907V (after the PTC)
3v3 -> 3.294V (on MEAS connector)
The charge led flashes unregular.
3. Standard situation, but only the 500mA charge current resistor ON .
5v -> 4.849V (after the PTC)
3v3 -> 3.294V (on MEAS connector)
The charge led flashes unregular.
4. Connect the board to a different PC (Standard situation, same cable, same setup)
With MM ESP32
5v -> 4.976V (after the PTC)
3v3 -> 3.319V (on MEAS connector)
The charge led is NOT flashing. Charge LED is off. I have different probes and depending on the probe the '+ 'will read 0V or 4.165V. Probably an impedance issue.
5. Connectetd to an external USB-type-C power supply (Standard situation)
5v -> 5.026V (after the PTC)
3v3 -> 3.32V (on MEAS connector)
The charge led is NOT flashing. Charge LED is off.
Why the charge led is flashing with the ESP32 and not with Artemis. Don’t know. But clearly, the power supply has an impact.