Devkit8500FAQ
This page mainly summarizes solutions to some main problems during the development of Embest Devkit8500. Hope it would give you some help.
Hardware problem
Why my new bought 7-inch LCD has no display when power on the board?
Answer: This is a very normal problem. Embest default delivery is preloaded with 4.3-inch LCD image. User needs to change the image for 7-inch LCD. Please follow the document "Devkit8500 Quick User Manual.pdf" included in product DVD.
Why the touch screen could not be used when getting into WinCE system?
Answer: When getting into WinCE system, the LCD displays as below, there is no response if using finger to click the center cross. There might be two reasons:
1. The touch screen is resistive touch screen, we suggest user using touch pen to click the center cross not finger;
2. It needs about one second touching for calibration, if touching time is too short, the operation will be invalid.
Linux problem
How to debug audio applications?
Answer: We are using ALSA audio library, please go to its offical website to download relative material. You would better confirm the ALSA version you used on your target board before downloading. Please get into file system and input: cat /proc/asound/version
After you confirmed the ALSA version, please download alsa-utils-xxx from:
http://www.alsa-project.org/main/index.php/Main_Page
There are source codes of aplay, arecord and more others for your reference.
WinCE problem
Why need touch screen calibration every time when getting into WinCE system?
Answer: Because Embest provides 4.3-inch and 7-inch LCDs for the board, different LCDs use different touch screen parameters, so it needs calibration every time.
However, we can solve the problem as below:
1. Open the Hyper-terminal and boot the WinCE system, do touch screen calibration once and check the Hyper-terminal information, you will see similar sentence like "CalibrationData"="2016,1888 1056,864 992,2912 3040,2976 3072,896"， these are parameters of touch screen.
2. Please add the touch screen parameters to BSP path: bsp/file/platform.reg
;-- Touch Screen driver --------------------------------------------------------
; @CESYSGEN IF CE_MODULES_POINTER
; @CESYSGEN IF GWES_TCHUI
; @XIPREGION IF PACKAGE_OEMDRIVERS
IF BSP_NOTOUCH !
[HKEY_LOCAL_MACHINE\HARDWARE\DEVICEMAP\TOUCH]
"DriverName"="touch.dll"
IF IMGNOCALIBRATION //mask this line
"CalibrationData"="2016,1888 1056,864 992,2912 3040,2976 3072,896" //These are parameters of your touch screen, please modify it to 4.3inch or 7inch
ENDIF IMGNOCALIBRATION //mask this line
"MaxCalError"="6"
"SPIAddr"=dword:0 ; McSPI1 channel 0
"PenGPIO"=dword:1B ; gpio27// gpio_175
"PenUpDebounceMS"=dword:28 ; PenUp debounce time in MS, 0 to disable debounce process
"InitialSamplesDropped"=dword:2 ; Number of samples to be dropped after pen down detection
; Default is 1
;"SampleRate"=dword:64 ; samples per second, default is 100
ENDIF BSP_NOTOUCH !
; @XIPREGION ENDIF PACKAGE_OEMDRIVERS
; @CESYSGEN ENDIF GWES_TCHUI
; @CESYSGEN ENDIF CE_MODULES_POINTER
