I make several battery power projects for microcontrollers like IR remote control. I seeking for commertial solutions and can't see less the $500 systems :(

So , i had problems measuring & calculating battery life with these projects , and decided to make some simple automatic measurement system with few bucs budget.

BOM:

stm32f103c6t6 (cheapest blue pill) ~($1.5)

st7789 spi display ~($2)

resistors + capacitors + wires + schottky diode ~(2$)

Requirement: 1uA - 150mA current with 5V-4V with precision +-5%

Lines on photo display:

current current mA :)

mean current   mA

current voltage V

time from start Sec

consumed energy in mAs

consumed energy in J

Can be used for  battery life calculation and debug low power modes of microcontrollers.

WIP