These are the examples provided for [[/users/frank26080115/libraries/LPC1700CMSIS_Lib/]] Note, the entire "program" is not compilable!
Diff: DAC/WaveGenerate/abstract.h
- Revision:
- 0:bf7b9fba3924
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/DAC/WaveGenerate/abstract.h Sun Mar 20 05:38:56 2011 +0000 @@ -0,0 +1,132 @@ + ******************** (C) COPYRIGHT 2010 NXPSemiconductors ******************* + * @file DAC\WaveGenerate\abstract.txt + * @author NXP MCU SW Application Team + * @version 2.0 + * @date + * @brief Description of the example to generate sinewave, triangle, + * escalator signal by DAC. + ****************************************************************************** + * Software that is described herein is for illustrative purposes only + * which provides customers with programming information regarding the + * products. This software is supplied "AS IS" without any warranties. + * NXP Semiconductors assumes no responsibility or liability for the + * use of the software, conveys no license or title under any patent, + * copyright, or mask work right to the product. NXP Semiconductors + * reserves the right to make changes in the software without + * notification. NXP Semiconductors also make no representation or + * warranty that such application will be suitable for the specified + * use without further testing or modification. + ****************************************************************************** + +@Example description: + Purpose: + This example describes how to use DMA to generate multi signal forms. + Process: + DAC will be initialized with maximum current is 700uA. This allows a maximum update rate of 1Mhz + Formula for ouput voltage on AOUT is: + AOUT = VALUE x ((Vrefp - Vrefn)/1024)+Vrefn + in which: + - Vrefp: tied to VDD(3.3V) + - Vrefn: tied to Vss + + DAC will generate a sinewave with peak to peak is within Vrefp and Vrefn. We need to prepare a + look up table with 60 items, each item is the value to update AOUT voltage, and it's correspondent + to a sample point of 1 circle sinewave signal. The formula is below: + for(i=0;i<NUM_SAMPLE_SINE;i++) //NUM_SAMPLE_SINE = 60 + { + dac_lut[i] = 512 + 512*sin(i); + dac_lut[i] = (dac_sine_lut[i]<<6); + } + For generating triangle wave signal, the following formula is used: + for(i=0;i<NUM_SAMPLE;i++) //NUM_SAMPLE=64 + { + if(i<32) dac_lut[i]= 32*i; + else if (i==32) dac_lut[i]= 1023; + else dac_lut[i] = 32*(NUM_SAMPLE-i); + dac_lut[i] = (dac_lut[i]<<6); + } + This will create a balance triangle. + Below is the formula for escalator case: + for(i=0;i<NUM_SAMPLE;i++) //NUM_SAMPLE=64 + { + dac_lut[i] = (1023/3)*(i/16); + dac_lut[i] = (dac_lut[i]<<6); + } + This will create an escalator with 4 steps. + + GPDMA channel 0 is configured in this example and used to transfer dac_lut[i] to DAC peripheral. + When the last item of dac_lut is transfered, GPDMA will roll back to transfer the first item. + + DAC is configured to use time out for each DAC value update and trigger GPDMA to fill DAC value register. + This time out value can also be used to calculate the signal frequency: + time out = (PCLK_DAC_IN_MHZ*1000000)/(SIGNAL_FREQ_IN_HZ*NUM_SAMPLE); + Where: - PCLK_DAC_IN_MHZ = 25 + - SIGNAL_FREQ_IN_HZ = 60 + - NUM_SAMPLE = 60 / 64 + + UART0 will display a menu, asks user to select the signal to generate: + 1) Sine + 2) Triangle + 3) Escalator + Select the signal type and observe AOUT signal by oscilloscope. + Press ESC if you want to terminate trasmitting the currect signal type + and generate other signal types. + +@Directory contents: + \EWARM: includes EWARM (IAR) project and configuration files + \Keil: includes RVMDK (Keil)project and configuration files + + lpc17xx_libcfg.h: Library configuration file - include needed driver library for this example + makefile: Example's makefile (to build with GNU toolchain) + dac_wave_generate.c: Main program + +@How to run: + Hardware configuration: + This example was tested on: + Keil MCB1700 with LPC1768 vers.1 + These jumpers must be configured as following: + - VDDIO: ON + - VDDREGS: ON + - VBUS: ON + - SPK: OFF + - Remain jumpers: OFF + IAR LPC1768 KickStart vers.A + These jumpers must be configured as following: + - PWR_SEL: depend on power source + - DBG_EN : ON + - Remain jumpers: OFF + + Serial display configuration: (e.g: TeraTerm, Hyperterminal, Flash Magic...) + 115200bps + 8 data bit + No parity + 1 stop bit + No flow control + + Running mode: + This example can run on RAM/ROM mode. + + Note: If want to burn hex file to board by using Flash Magic, these jumpers need + to be connected: + - MCB1700 with LPC1768 ver.1: + + RST: ON + + ISP: ON + - IAR LPC1768 KickStart vers.A: + + RST_E: ON + + ISP_E: ON + + (Please reference "LPC1000 Software Development Toolchain" - chapter 4 "Creating and working with + LPC1000CMSIS project" for more information) + + Step to run: + - Step 1: Build example. + - Step 2: Burn hex file into board (if run on ROM mode) + - Step 3: Connect UART0 on this board to COM port on your computer + - Step 4: Configure hardware and serial display as above instruction + - Step 5: Run example and observe AOUT signal by oscilloscope + + (Pls see "LPC17xx Example Description" document - chapter "Examples > DAC > WaveGenerate" + for more details) +@Tip: + - Open \EWARM\*.eww project file to run example on IAR + - Open \RVMDK\*.uvproj project file to run example on Keil \ No newline at end of file