KLST_PANDA Prototyping
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
- dimming backlight (FAN5333) with PWM + 40-pin TFT Friend - FPC Breakout with LED Backlight Driver
- capacitive touch interface (ADS7843)
- parallel LTDC interface ( is external memory required? )
- decide ( and order ) displays (13×) ( see research.KLST_PANDA–TFTs.md )
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
- test audio codec (WM8904)
- with PIC32 AUDIO CODEC DAUGHTER CARD (AC328904)
SDCard
- test 4-bit wide
SDIO/SDMMC
interface - test card detect functionality
ADC+DAC
- test ADC
- test DAC
microphone
- test MEMS microphone ( via I2S )
- with Adafruit I2S MEMS Microphone Breakout - SPH0645LM4H
@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
- 2×
- 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
- MEMS microphone ( via I2S )
- e.g GMA4030H11-F26
- 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
- 2×
- 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”