Eval¶

V2¶

New version with I2C EEPROM? Oh wait, there is an internal EEPROM.
Uart not even neccessary. Fancy GDB-Magic can be used.
At the moment its probably an STM32L011F4P6. Uart for configuring is needed. "Customer" should be able to configure it with adapter via USB.
So UART would be nice then. Assume its already wired correctly.

An adapter for UART to USB would be nice. So able to configure it without STLink. MCP2221 looks good. Ophio

STM32L031F6
STM32L031F6P6 has 32KB.January 2022; 2,22920€ 25pc. EEPROM is also integrated. Pin-kompability to be checked.
STM32L031F6P7 is 2,38520€ 25pc. 717 available. Link
Pins are the same, Uart is on the same pins. Buzzer same, SWD same.

UART works as expected (STM32L011). Binary Size is still ok (Release only, Debug not possible).
STerm is way to big (4K over size). Have to look whats the issue there. Faking a 64K Version, making full debug image and check symbol sizes.

Battery life¶

Unterschwelleneffekt / leakage current

Buzzer is now driven by MOSFET. The "Zero Gate Voltage Drain Current" is relevant for battery life in unused status.
Nexpedia
Most manufactures specify an "Zero Gate Voltage Drain Current" of 1µA at 20-30V. Temperature has an big impact.

Vergleichen mit verwendetem Transistor;
NPN (3.2.2019)
IE scheint 0, ICB ist mit 100nA angegeben

Einfach Messen... ist sowieso ein guter Geraete-Test

150-280mAh, Panasonic: 220mAh
5-9h bei 30mA

Buzzer:
3/(16+22)=80mA (permanent)-> 40mA; 5,5h
3 / (16 + 51) = 45mA -> 22,5mA; 9,7h

Power Range¶

The MCU STM32L031x4 runs with 1.65V to 3.6V. Battery1 Battery2 specify a capacity of 235mAh to 2.0 volts
LEDs should be visible at 2Volts. VGS@2.0V should bring ID of 6A.

The white LED probably has to be replaced.

The violet led was not so picki (The one at the debug board can be enspected).
If this is ok, a white led in the same voltage range can be ordered. https://www.tme.eu/Document/64e15c1a036957b6f84022f15b00ad5b/OSXX0603C1E.pdf