1 // Copyright 2013 Emilie Gillet.
2 //
3 // Author: Emilie Gillet (emilie.o.gillet@gmail.com)
4 //
5 // Permission is hereby granted, free of charge, to any person obtaining a copy
6 // of this software and associated documentation files (the "Software"), to deal
7 // in the Software without restriction, including without limitation the rights
8 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
9 // copies of the Software, and to permit persons to whom the Software is
10 // furnished to do so, subject to the following conditions:
11 //
12 // The above copyright notice and this permission notice shall be included in
13 // all copies or substantial portions of the Software.
14 //
15 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
21 // THE SOFTWARE.
22 //
23 // See http://creativecommons.org/licenses/MIT/ for more information.
24 //
25 // -----------------------------------------------------------------------------
26 //
27 // Driver for DAC.
28 
29 #ifndef TIDES_DRIVERS_DAC_H_
30 #define TIDES_DRIVERS_DAC_H_
31 
32 #include "stmlib/stmlib.h"
33 
34 #include <stm32f10x_conf.h>
35 
36 namespace tides {
37 
38 const uint16_t kPinSS = GPIO_Pin_12;
39 
40 class Dac {
41  public:
Dac()42   Dac() { }
~Dac()43   ~Dac() { }
44 
45   void Init();
46 
Write(uint16_t channel_1,uint16_t channel_2)47   void Write(uint16_t channel_1, uint16_t channel_2) {
48     data_[0] = channel_1;
49     data_[1] = channel_2;
50   }
51 
ready()52   bool ready() { return active_channel_ == 0; }
53 
Update()54   inline void Update() {
55     GPIOB->BSRR = kPinSS;
56     GPIOB->BRR = kPinSS;
57     if (active_channel_ == 0) {
58       SPI2->DR = 0x1000 | (data_[0] >> 8);
59       while (!(SPI2->SR & SPI_I2S_FLAG_RXNE));
60       SPI2->DR = (data_[0] << 8) & 0xffff;
61       active_channel_ = 1;
62     } else {
63       SPI2->DR = 0x2400 | (data_[1] >> 8);
64       while (!(SPI2->SR & SPI_I2S_FLAG_RXNE));
65       SPI2->DR = (data_[1] << 8) & 0xffff;
66       active_channel_ = 0;
67     }
68   }
69 
Update(uint8_t channel)70   inline void Update(uint8_t channel) {
71     GPIOB->BSRR = kPinSS;
72     GPIOB->BRR = kPinSS;
73     if (channel == 0) {
74       SPI2->DR = 0x1000 | (data_[0] >> 8);
75       while (!(SPI2->SR & SPI_I2S_FLAG_RXNE));
76       SPI2->DR = (data_[0] << 8) & 0xffff;
77     } else {
78       SPI2->DR = 0x2400 | (data_[1] >> 8);
79       while (!(SPI2->SR & SPI_I2S_FLAG_RXNE));
80       SPI2->DR = (data_[1] << 8) & 0xffff;
81     }
82   }
83 
84  private:
85   uint16_t data_[2];
86   uint8_t active_channel_;
87 
88   DISALLOW_COPY_AND_ASSIGN(Dac);
89 };
90 
91 }  // namespace tides
92 
93 #endif  // TIDES_DRIVERS_DAC_H_
94