Electronics design
Design review
A first draft of the schematics and layout is available for review:
- In the repo, under mcattin_hw_dev branch.
- Schematics PDF version.
- Layout PDF version.
- PCB production files ZIP file.
Apart from a general review, here are some specific points to be checked:
What | Who | Status |
Symbols and footprints pinout | Tom checked the MCU | |
Battery charger and fuel gauge connections (GND) | To do | |
MCU peripherals connections (pins can't be connected to any peripheral) |
To do | |
MCU debug port, reset | To do | |
MCU clock sources | To do | |
Is USB low-speed needed? (pull-up on DM line) | To do | |
Do we need ferrites on USB power lines? | To do | |
Is powering the LCD from a MCU pin ok? | To do | |
Is the 150mA LDO enough? (pin compatible 250mA if needed) | To do | |
Is anything missing? | To do |
MCU
Bootloader
To enter the bootloader, DBG_SWCLK (PF0) must be pulled high and the
EFM32 must be reset.
See application note
AN0042
=> We should find a way to run the bootloader from the main application (without having to reset the EFM32).
GPS
Passive antenna
GPS RF design guidelines
Low power design
Power profiling?
Foresee sensors, test points on the PCB?