From 7b391d7f76a2d56242420c560d65f00a60f78682 Mon Sep 17 00:00:00 2001 From: bnewbold Date: Sat, 7 Aug 2010 20:29:37 -0400 Subject: basic working dac implementation --- examples/test-dac.cpp | 53 +++++++++++++++++++++++++ libmaple/dac.c | 67 +++++++++++++++++++++++++++++++ libmaple/dac.h | 108 ++++++++++++++++++++++++++++++++++++++++++++++++++ libmaple/rcc.h | 3 ++ libmaple/rules.mk | 1 + notes/dac.txt | 32 +++++++++++++++ 6 files changed, 264 insertions(+) create mode 100644 examples/test-dac.cpp create mode 100644 libmaple/dac.c create mode 100644 libmaple/dac.h create mode 100644 notes/dac.txt diff --git a/examples/test-dac.cpp b/examples/test-dac.cpp new file mode 100644 index 0000000..65496f4 --- /dev/null +++ b/examples/test-dac.cpp @@ -0,0 +1,53 @@ + +#include "wirish.h" +#include "fsmc.h" +#include "rcc.h" +#include "gpio.h" +#include "dac.h" + +#define LED_PIN 23 // hack for maple native +#define DISC_PIN 14 // hack for USB on native + +int toggle = 0; +uint16 count = 0; + +void setup() { + + pinMode(LED_PIN, OUTPUT); + pinMode(DISC_PIN, OUTPUT); + digitalWrite(DISC_PIN,1); + digitalWrite(LED_PIN,1); + + Serial1.begin(9600); + Serial1.println("Hello World!"); + + Serial1.print("Init... "); + dac_init(); + Serial1.println("Done."); +} + +void loop() { + digitalWrite(LED_PIN, toggle); + toggle ^= 1; + delay(100); + + count += 100; + + if(count > 4095) { + count = 0; + } + + dac_write(1, 2048); + dac_write(2, count); +} + +int main(void) { + init(); + setup(); + + while (1) { + loop(); + } + return 0; +} + diff --git a/libmaple/dac.c b/libmaple/dac.c new file mode 100644 index 0000000..b9c7d63 --- /dev/null +++ b/libmaple/dac.c @@ -0,0 +1,67 @@ + +/* ***************************************************************************** + * The MIT License + * + * Copyright (c) 2010 Bryan Newbold. + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + * ****************************************************************************/ + +#include "libmaple.h" +#include "rcc.h" +#include "gpio.h" +#include "dac.h" + +// Only one, so global to this file +DAC_Map *dac = (DAC_Map*)(DAC_BASE); + +// This numbering follows the registers (1-indexed) +#define DAC_CHA 1 +#define DAC_CHB 2 + +// Sets up the DAC peripheral +void dac_init(void) { + + // First turn on the clock + rcc_enable_clk_dac(); + + // Then setup ANALOG mode on PA4 and PA5 + gpio_set_mode(GPIOA_BASE, 4, CNF_INPUT_ANALOG); + gpio_set_mode(GPIOA_BASE, 5, CNF_INPUT_ANALOG); + + // Then do register stuff. + // Default does no triggering, and buffered output, so all good. + dac->CR |= DAC_CR_EN1; + dac->CR |= DAC_CR_EN2; + +} + +void dac_write(uint8 chan, uint16 val) { + + switch(chan) { + case DAC_CHA: + dac->DHR12R1 = 0x0FFF & val; + break; + case DAC_CHB: + dac->DHR12R2 = 0x0FFF & val; + break; + default: + ASSERT(0); // Shouldn't get here + } +} diff --git a/libmaple/dac.h b/libmaple/dac.h new file mode 100644 index 0000000..de1fd3f --- /dev/null +++ b/libmaple/dac.h @@ -0,0 +1,108 @@ +/* ***************************************************************************** + * The MIT License + * + * Copyright (c) 2010 Bryan Newbold. + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + * ****************************************************************************/ + +/* + * See ../notes/dac.txt for more info + */ + +#ifndef _DAC_H_ +#define _DAC_H_ + +#ifdef __cplusplus +extern "C"{ +#endif + +#define DAC_BASE 0x40007400 + +typedef struct { + volatile uint32 CR; + volatile uint32 SWTRIGR; + volatile uint32 DHR12R1; + volatile uint32 DHR12L1; + volatile uint32 DHR8R1; + volatile uint32 DHR12R2; + volatile uint32 DHR12L2; + volatile uint32 DHR8R2; + volatile uint32 DHR12RD; + volatile uint32 DHR12LD; + volatile uint32 DHR8RD; + volatile uint32 DOR1; + volatile uint32 DOR2; +} DAC_Map; + + +// And here are the register bit ranges +#define DAC_CR_EN1 BIT(0) +#define DAC_CR_BOFF1 BIT(1) +#define DAC_CR_TEN1 BIT(2) +#define DAC_CR_TSEL1 (BIT(3) | BIT(4) | BIT(5)) +#define DAC_CR_WAVE1 (BIT(6) | BIT(7)) +#define DAC_CR_MAMP1 (BIT(8) | BIT(9) | BIT(10) | BIT(11)) +#define DAC_CR_DMAEN1 BIT(12) +#define DAC_CR_EN2 BIT(16) +#define DAC_CR_BOFF2 BIT(17) +#define DAC_CR_TEN2 BIT(18) +#define DAC_CR_TSEL2 (BIT(19) | BIT(20) | BIT(21)) +#define DAC_CR_WAVE2 (BIT(22) | BIT(23)) +#define DAC_CR_MAMP2 (BIT(24) | BIT(25) | BIT(26) | BIT(27)) +#define DAC_CR_DMAEN2 BIT(28) + +#define DAC_SWTRIGR_SWTRIG1 BIT(0) +#define DAC_SWTRIGR_SWTRIG2 BIT(1) + +#define DAC_DHR12R1_DACC1DHR 0x00000FFF + +#define DAC_DHR12L1_DACC1DHR 0x0000FFF0 + +#define DAC_DHR8R1_DACC1DHR 0x000000FF + +#define DAC_DHR12R2_DACC2DHR 0x00000FFF + +#define DAC_DHR12L2_DACC2DHR 0x0000FFF0 + +#define DAC_DHR8R2_DACC2DHR 0x000000FF + +#define DAC_DHR12RD_DACC1DHR 0x00000FFF +#define DAC_DHR12RD_DACC2DHR 0x0FFF0000 + +#define DAC_DHR12LD_DACC1DHR 0x0000FFF0 +#define DAC_DHR12LD_DACC2DHR 0xFFF00000 + +#define DAC_DHR8RD_DACC1DHR 0x000000FF +#define DAC_DHR8RD_DACC2DHR 0x0000FF00 + +#define DAC_DOR1 0x00000FFF + +#define DAC_DOR2 0x00000FFF + + +void dac_init(void); +void dac_write(uint8 chan, uint16 val); + +#ifdef __cplusplus +} // extern "C" +#endif + + +#endif diff --git a/libmaple/rcc.h b/libmaple/rcc.h index 8ad70e5..2dca151 100644 --- a/libmaple/rcc.h +++ b/libmaple/rcc.h @@ -139,6 +139,7 @@ struct rcc_device { #define RCC_APB1ENR_USART3EN BIT(18) #define RCC_APB1ENR_SPI2EN BIT(14) #define RCC_APB1ENR_USB BIT(23) +#define RCC_APB1ENR_DACEN BIT(29) /* AHB peripheral clock enable bits */ #define RCC_AHBENR_DMA1EN BIT(0) @@ -174,6 +175,8 @@ struct rcc_device { #define rcc_enable_clk_adc1() __set_bits(RCC_APB2ENR, RCC_APB2ENR_ADC1EN) +#define rcc_enable_clk_dac() __set_bits(RCC_APB1ENR, RCC_APB1ENR_DACEN) + #define rcc_reset_adc1() { __set_bits(RCC_APB2RSTR, RCC_APB2RSTR_ADC1RST); \ __clear_bits(RCC_APB2RSTR, RCC_APB2RSTR_ADC1RST); \ } diff --git a/libmaple/rules.mk b/libmaple/rules.mk index db9540a..8428277 100644 --- a/libmaple/rules.mk +++ b/libmaple/rules.mk @@ -26,6 +26,7 @@ cSRCS_$(d) := systick.c \ flash.c \ spi.c \ fsmc.c \ + dac.c \ usb/usb.c \ usb/usb_callbacks.c \ usb/usb_hardware.c \ diff --git a/notes/dac.txt b/notes/dac.txt new file mode 100644 index 0000000..9df0782 --- /dev/null +++ b/notes/dac.txt @@ -0,0 +1,32 @@ + +DAC notes (for maple native and other "high density" STM32 devices) +------------------------------------------------------------------------------- +There is an ST application note for the DACs; it provides a lot of context but +doesn't help setup the peripheral very much. + +For the first code iteration we'll just use 12-bit right-aligned single writes, +so use DAC_DHR12Rx + +Once data is loaded into the digital registers, there are a number of possible +triggers to start conversion to analog output: external interrupts, software +control, and timer events. We'll just use software triggering for now. + +There is (obviously) DMA support for DAC output. + +There are noise output and triangle wave output features with variable +amplitude. + +There are many additional modes to tigger output to both channels at the same +time. + +Buffering will be enabled by default. + +TODO +------------------------------------------------------------------------------- +- sine wave demo using Timer interrupts +- wirish implementation +- documentation +- higher performance modes? +- signal quality testing +- DMA output + -- cgit v1.2.3