1+ // Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
2+ //
3+ // Licensed under the Apache License, Version 2.0 (the "License");
4+ // you may not use this file except in compliance with the License.
5+ // You may obtain a copy of the License at
6+
7+ // http://www.apache.org/licenses/LICENSE-2.0
8+ //
9+ // Unless required by applicable law or agreed to in writing, software
10+ // distributed under the License is distributed on an "AS IS" BASIS,
11+ // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12+ // See the License for the specific language governing permissions and
13+ // limitations under the License.
14+
15+ #if defined(ESP_H)
16+
17+ #include " esp32_adc_driver.h"
18+ #include " Arduino.h"
19+
20+ #include " freertos/FreeRTOS.h"
21+ #include " freertos/task.h"
22+ #include " rom/ets_sys.h"
23+ #include " esp_attr.h"
24+ #include " esp_intr.h"
25+ #include " soc/rtc_io_reg.h"
26+ #include " soc/rtc_cntl_reg.h"
27+ #include " soc/sens_reg.h"
28+
29+ static uint8_t __analogAttenuation = 3 ;// 11db
30+ static uint8_t __analogWidth = 3 ;// 12 bits
31+ static uint8_t __analogCycles = 8 ;
32+ static uint8_t __analogSamples = 0 ;// 1 sample
33+ static uint8_t __analogClockDiv = 1 ;
34+
35+ // Width of returned answer ()
36+ static uint8_t __analogReturnedWidth = 12 ;
37+
38+ void __analogSetWidth (uint8_t bits){
39+ if (bits < 9 ){
40+ bits = 9 ;
41+ } else if (bits > 12 ){
42+ bits = 12 ;
43+ }
44+ __analogReturnedWidth = bits;
45+ __analogWidth = bits - 9 ;
46+ SET_PERI_REG_BITS (SENS_SAR_START_FORCE_REG, SENS_SAR1_BIT_WIDTH, __analogWidth, SENS_SAR1_BIT_WIDTH_S);
47+ SET_PERI_REG_BITS (SENS_SAR_READ_CTRL_REG, SENS_SAR1_SAMPLE_BIT, __analogWidth, SENS_SAR1_SAMPLE_BIT_S);
48+
49+ SET_PERI_REG_BITS (SENS_SAR_START_FORCE_REG, SENS_SAR2_BIT_WIDTH, __analogWidth, SENS_SAR2_BIT_WIDTH_S);
50+ SET_PERI_REG_BITS (SENS_SAR_READ_CTRL2_REG, SENS_SAR2_SAMPLE_BIT, __analogWidth, SENS_SAR2_SAMPLE_BIT_S);
51+ }
52+
53+ void __analogSetCycles (uint8_t cycles){
54+ __analogCycles = cycles;
55+ SET_PERI_REG_BITS (SENS_SAR_READ_CTRL_REG, SENS_SAR1_SAMPLE_CYCLE, __analogCycles, SENS_SAR1_SAMPLE_CYCLE_S);
56+ SET_PERI_REG_BITS (SENS_SAR_READ_CTRL2_REG, SENS_SAR2_SAMPLE_CYCLE, __analogCycles, SENS_SAR2_SAMPLE_CYCLE_S);
57+ }
58+
59+ void __analogSetSamples (uint8_t samples){
60+ if (!samples){
61+ return ;
62+ }
63+ __analogSamples = samples - 1 ;
64+ SET_PERI_REG_BITS (SENS_SAR_READ_CTRL_REG, SENS_SAR1_SAMPLE_NUM, __analogSamples, SENS_SAR1_SAMPLE_NUM_S);
65+ SET_PERI_REG_BITS (SENS_SAR_READ_CTRL2_REG, SENS_SAR2_SAMPLE_NUM, __analogSamples, SENS_SAR2_SAMPLE_NUM_S);
66+ }
67+
68+ void __analogSetClockDiv (uint8_t clockDiv){
69+ if (!clockDiv){
70+ return ;
71+ }
72+ __analogClockDiv = clockDiv;
73+ SET_PERI_REG_BITS (SENS_SAR_READ_CTRL_REG, SENS_SAR1_CLK_DIV, __analogClockDiv, SENS_SAR1_CLK_DIV_S);
74+ SET_PERI_REG_BITS (SENS_SAR_READ_CTRL2_REG, SENS_SAR2_CLK_DIV, __analogClockDiv, SENS_SAR2_CLK_DIV_S);
75+ }
76+
77+ void __analogSetAttenuation (uint8_t attenuation)
78+ {
79+ __analogAttenuation = attenuation & 3 ;
80+ uint32_t att_data = 0 ;
81+ int i = 10 ;
82+ while (i--){
83+ att_data |= __analogAttenuation << (i * 2 );
84+ }
85+ WRITE_PERI_REG (SENS_SAR_ATTEN1_REG, att_data & 0xFFFF );// ADC1 has 8 channels
86+ WRITE_PERI_REG (SENS_SAR_ATTEN2_REG, att_data);
87+ }
88+
89+ void IRAM_ATTR __analogInit (){
90+ static bool initialized = false ;
91+ if (initialized){
92+ return ;
93+ }
94+
95+ __analogSetAttenuation (__analogAttenuation);
96+ __analogSetCycles (__analogCycles);
97+ __analogSetSamples (__analogSamples + 1 );// in samples
98+ __analogSetClockDiv (__analogClockDiv);
99+ __analogSetWidth (__analogWidth + 9 );// in bits
100+
101+ SET_PERI_REG_MASK (SENS_SAR_READ_CTRL_REG, SENS_SAR1_DATA_INV);
102+ SET_PERI_REG_MASK (SENS_SAR_READ_CTRL2_REG, SENS_SAR2_DATA_INV);
103+
104+ SET_PERI_REG_MASK (SENS_SAR_MEAS_START1_REG, SENS_MEAS1_START_FORCE_M); // SAR ADC1 controller (in RTC) is started by SW
105+ SET_PERI_REG_MASK (SENS_SAR_MEAS_START1_REG, SENS_SAR1_EN_PAD_FORCE_M); // SAR ADC1 pad enable bitmap is controlled by SW
106+ SET_PERI_REG_MASK (SENS_SAR_MEAS_START2_REG, SENS_MEAS2_START_FORCE_M); // SAR ADC2 controller (in RTC) is started by SW
107+ SET_PERI_REG_MASK (SENS_SAR_MEAS_START2_REG, SENS_SAR2_EN_PAD_FORCE_M); // SAR ADC2 pad enable bitmap is controlled by SW
108+
109+ CLEAR_PERI_REG_MASK (SENS_SAR_MEAS_WAIT2_REG, SENS_FORCE_XPD_SAR_M); // force XPD_SAR=0, use XPD_FSM
110+ SET_PERI_REG_BITS (SENS_SAR_MEAS_WAIT2_REG, SENS_FORCE_XPD_AMP, 0x2 , SENS_FORCE_XPD_AMP_S); // force XPD_AMP=0
111+
112+ CLEAR_PERI_REG_MASK (SENS_SAR_MEAS_CTRL_REG, 0xfff << SENS_AMP_RST_FB_FSM_S); // clear FSM
113+ SET_PERI_REG_BITS (SENS_SAR_MEAS_WAIT1_REG, SENS_SAR_AMP_WAIT1, 0x1 , SENS_SAR_AMP_WAIT1_S);
114+ SET_PERI_REG_BITS (SENS_SAR_MEAS_WAIT1_REG, SENS_SAR_AMP_WAIT2, 0x1 , SENS_SAR_AMP_WAIT2_S);
115+ SET_PERI_REG_BITS (SENS_SAR_MEAS_WAIT2_REG, SENS_SAR_AMP_WAIT3, 0x1 , SENS_SAR_AMP_WAIT3_S);
116+ while (GET_PERI_REG_BITS2 (SENS_SAR_SLAVE_ADDR1_REG, 0x7 , SENS_MEAS_STATUS_S) != 0 ); // wait det_fsm==
117+
118+ initialized = true ;
119+ }
120+
121+ void __analogSetPinAttenuation (uint8_t pin, uint8_t attenuation)
122+ {
123+ int8_t channel = digitalPinToAnalogChannel (pin);
124+ if (channel < 0 || attenuation > 3 ){
125+ return ;
126+ }
127+ __analogInit ();
128+ if (channel > 7 ){
129+ SET_PERI_REG_BITS (SENS_SAR_ATTEN2_REG, 3 , attenuation, ((channel - 10 ) * 2 ));
130+ } else {
131+ SET_PERI_REG_BITS (SENS_SAR_ATTEN1_REG, 3 , attenuation, (channel * 2 ));
132+ }
133+ }
134+
135+ bool IRAM_ATTR __adcAttachPin (uint8_t pin){
136+
137+ int8_t channel = digitalPinToAnalogChannel (pin);
138+ if (channel < 0 ){
139+ return false ;// not adc pin
140+ }
141+
142+ int8_t pad = digitalPinToTouchChannel (pin);
143+ if (pad >= 0 ){
144+ uint32_t touch = READ_PERI_REG (SENS_SAR_TOUCH_ENABLE_REG);
145+ if (touch & (1 << pad)){
146+ touch &= ~((1 << (pad + SENS_TOUCH_PAD_OUTEN2_S))
147+ | (1 << (pad + SENS_TOUCH_PAD_OUTEN1_S))
148+ | (1 << (pad + SENS_TOUCH_PAD_WORKEN_S)));
149+ WRITE_PERI_REG (SENS_SAR_TOUCH_ENABLE_REG, touch);
150+ }
151+ } else if (pin == 25 ){
152+ CLEAR_PERI_REG_MASK (RTC_IO_PAD_DAC1_REG, RTC_IO_PDAC1_XPD_DAC | RTC_IO_PDAC1_DAC_XPD_FORCE); // stop dac1
153+ } else if (pin == 26 ){
154+ CLEAR_PERI_REG_MASK (RTC_IO_PAD_DAC2_REG, RTC_IO_PDAC2_XPD_DAC | RTC_IO_PDAC2_DAC_XPD_FORCE); // stop dac2
155+ }
156+
157+ pinMode (pin, ANALOG);
158+
159+ __analogInit ();
160+ return true ;
161+ }
162+
163+ bool IRAM_ATTR __adcStart (uint8_t pin){
164+
165+ int8_t channel = digitalPinToAnalogChannel (pin);
166+ if (channel < 0 ){
167+ return false ;// not adc pin
168+ }
169+
170+ if (channel > 9 ){
171+ channel -= 10 ;
172+ CLEAR_PERI_REG_MASK (SENS_SAR_MEAS_START2_REG, SENS_MEAS2_START_SAR_M);
173+ SET_PERI_REG_BITS (SENS_SAR_MEAS_START2_REG, SENS_SAR2_EN_PAD, (1 << channel), SENS_SAR2_EN_PAD_S);
174+ SET_PERI_REG_MASK (SENS_SAR_MEAS_START2_REG, SENS_MEAS2_START_SAR_M);
175+ } else {
176+ CLEAR_PERI_REG_MASK (SENS_SAR_MEAS_START1_REG, SENS_MEAS1_START_SAR_M);
177+ SET_PERI_REG_BITS (SENS_SAR_MEAS_START1_REG, SENS_SAR1_EN_PAD, (1 << channel), SENS_SAR1_EN_PAD_S);
178+ SET_PERI_REG_MASK (SENS_SAR_MEAS_START1_REG, SENS_MEAS1_START_SAR_M);
179+ }
180+ return true ;
181+ }
182+
183+ bool IRAM_ATTR __adcBusy (uint8_t pin){
184+
185+ int8_t channel = digitalPinToAnalogChannel (pin);
186+ if (channel < 0 ){
187+ return false ;// not adc pin
188+ }
189+
190+ if (channel > 7 ){
191+ return (GET_PERI_REG_MASK (SENS_SAR_MEAS_START2_REG, SENS_MEAS2_DONE_SAR) == 0 );
192+ }
193+ return (GET_PERI_REG_MASK (SENS_SAR_MEAS_START1_REG, SENS_MEAS1_DONE_SAR) == 0 );
194+ }
195+
196+ uint16_t IRAM_ATTR __adcEnd (uint8_t pin)
197+ {
198+
199+ uint16_t value = 0 ;
200+ int8_t channel = digitalPinToAnalogChannel (pin);
201+ if (channel < 0 ){
202+ return 0 ;// not adc pin
203+ }
204+ if (channel > 7 ){
205+ while (GET_PERI_REG_MASK (SENS_SAR_MEAS_START2_REG, SENS_MEAS2_DONE_SAR) == 0 ); // wait for conversion
206+ value = GET_PERI_REG_BITS2 (SENS_SAR_MEAS_START2_REG, SENS_MEAS2_DATA_SAR, SENS_MEAS2_DATA_SAR_S);
207+ } else {
208+ while (GET_PERI_REG_MASK (SENS_SAR_MEAS_START1_REG, SENS_MEAS1_DONE_SAR) == 0 ); // wait for conversion
209+ value = GET_PERI_REG_BITS2 (SENS_SAR_MEAS_START1_REG, SENS_MEAS1_DATA_SAR, SENS_MEAS1_DATA_SAR_S);
210+ }
211+
212+ // Shift result if necessary
213+ uint8_t from = __analogWidth + 9 ;
214+ if (from == __analogReturnedWidth) {
215+ return value;
216+ }
217+ if (from > __analogReturnedWidth) {
218+ return value >> (from - __analogReturnedWidth);
219+ }
220+ return value << (__analogReturnedWidth - from);
221+ }
222+
223+ void __analogReadResolution (uint8_t bits)
224+ {
225+ if (!bits || bits > 16 ){
226+ return ;
227+ }
228+ __analogSetWidth (bits); // hadware from 9 to 12
229+ __analogReturnedWidth = bits; // software from 1 to 16
230+ }
231+
232+ uint16_t IRAM_ATTR adcRead (uint8_t pin)
233+ {
234+ if (!__adcAttachPin (pin) || !__adcStart (pin)){
235+ return 0 ;
236+ }
237+ return __adcEnd (pin);
238+ }
239+
240+ #endif
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