2023-04-17-KLST_PANDA-Prototyping--PIN-assignment

i will start the prototyping with ST’s development board NUCLEO-H723ZG. it allows to test most ( not all ) features and peripherals. PS { the boards connectors need to be equipped with double-row pin headers first … grrrmpf }

i am still struggling with one fundamental decision and that is whether i should produce smaller PCBs ( e.g for external memory BGA-24 IC ) and test them individually or if i should just take a leap of faith and design the entire board, planning 1–2 revision rounds. hmmm, difficult …

these are the sections or modules i want to test:

display

external memory

  • BGA-24 memory (APS12808L-3OBM-BA)
  • Octo-SPI/HyperRAM™ interface
  • not sure how to test the BGA-24 memory IC? to just have this manufactured as a PCB seems a bit excessive

battery + power supply

  • test charging circuit (TP5400)
  • with Lolin D1 Mini Battery Shield
  • test with battery type 18650
  • can the circuit charge and supply power simultanously?
  • do we need a hardware on/off-switch? or can this also be done in software?

USB-C

  • are 2× USB-C connectors required or would a single one work?
  • one for charging or power supply
  • … and one for USB Device/Host where it could also power the board when connected as a ‌USB Device

audio codec

SDCard

  • test 4-bit wide SDIO/SDMMC interface
  • test card detect functionality

ADC+DAC

  • test ADC
  • test DAC

microphone


@todo(elaborate on the details) @todo(see 2022-07-19-KLST_PANDA_starting_design_phase.md )

  • MCU: STM32H723ZGT
  • display
    • 4.3” 480×272
    • capacitive touch ( ADS7843 )
    • dimmable backlight ( PWM+FAN5333 )
    • LTDC interface ( parallel )
  • rechargable battery
    • type 18650
    • with PCB mounted holder e.g MY-18650-01
    • recharging circuit?
    • see KLST_GRASS
  • USB-C
    • one for charging
    • one for USB Device/Host devices
  • audio codec
    • WM8904
  • external memory
    • APS12808L-3OBM-BA
    • Octo-SPI/HyperRAM™ interface
  • SDCard
    • 4-bit wide bus
    • with card detect
  • microphone
  • DAC+ADC
    • DAC(1×)+ADC(3×)
    • connection to modular synth?!?
    • 12V tolerant ( or modular connection as extension board = 0.0—3.3V > -12.0–12.0V + -1.0–1.0V>-5.0>5.0V(?) )
  • GPIO
    • what layout?
    • maybe case with fake shrouded connectors ( see IDC housing )
  • LEDs
    • only 3 LEDs
  • buttons
    • reset, boot, programmer
  • mechanical keybord keys
    • just below encoders?
  • programmer interface
    • STD14
    • pogo pin connector ( without housing on front-side )
  • case+shape
    • switch?
    • portrait mode?
    • something unique!!!
    • hole for a strap
    • black&white PCB
  • on/off switch(?) “just thought that when we have a battery on board there might be the need to be able to switch the power supply on or off”