See BuildrootOrangePiPc (fast boot)
Notes about ECU serial external datalogger
- request runtime data via (bidirectional, full duplex) 1st serial port of VEMS ECU
- log to SD card
- in .vemslog format
- with timestamps if RTC available
- USB mass storage device to PC, so files from SD can be transferred to PC fast (normally without removing SD).
Currently implemented on STM32F103C8T6 (using device' built-in RTC and USB).
Considering: porting to Orange PI PC (or lite / one / zero / plus or similar)
- with optional header-connected I2C RTC (useful if no ntp/GSM/wifi internet or other time-source)
- the immensely powerful device can be "double"-used for many apps simultaneously, even cloud apps: secure wallet, or file sharing, audio/video communications / capture (and motion)
- perhaps recording audio before rally race could log more information about date, environment, vehicle than an RTC would provide,
- and perhaps even running vemstune (although a bit slow for logviewer, and the linux build kinda works, but hasn't been too agressively tested for stability)
STM => Orange PI PC notes
- logging to (unix) file instead of self-handled FAT FS on SD block device
- the timestamp is handled automatically
- using high level /dev/ttySx or /dev/ttyUSB0 or similar serial port, instead of stm32's raw UART.
- mainloop: select() instead of busyloop (considered kind in generic multitasking environment)
- optional: data relay
- if serial data is coming without request, sending (relaying) the same RAW data to the TX would make (perhaps) sense.
- This way ECU TX => ARM => VT => ECU RX could be implemented (when no VT, just plug in a dummy DSUB9 with 2-3 connected to close the loop )
- alternatively ARM could be sniffing the ECU TX => VT line (and ARM => ECU only activated when PC/VT serial is disconnected). No serial relay is needed in the ARM for this.
- However, '''ARM best have v3 ECU config (only needed for EGT cal, assuming 72.5 would work well though, as egt calibration is 72 usually)
- ECU config requested at startup, which might not be available if VT is started before ARM (not the normal usecase, but worths to consider)
Orange PI PC arm-hf binary __might be__ compatible with raspberry arm-hf 32 bit (although raspberry is not an initial target, and might not be supported)
- perhaps depends on Debian Jessie or Ubuntu library details, if that is used (slow boot)
- Orange PI PC H5 and Raspberry 3 in 64 bit mode need different compile (64 bit toolchain)