git.gag.com Git - fw/altos/blob - src/drivers/ao_ads124s0x.c

   1 /*
   2  * Copyright © 2019 Bdale Garbee <bdale@gag.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  */
  14
  15 #include <ao.h>
  16 #include <ao_exti.h>
  17 #include "ao_ads124s0x.h"
  18
  19 #define DEBUG_LOW       1
  20 #define DEBUG_HIGH      2
  21
  22 #define DEBUG           0
  23
  24 #if DEBUG
  25 #define PRINTD(l, ...) do { if (DEBUG & (l)) { printf ("\r%5u %s: ", ao_tick_count, __func__); printf(__VA_ARGS__); flush(); } } while(0)
  26 #else
  27 #define PRINTD(l,...)
  28 #endif
  29
  30 struct ao_ads124s0x_sample      ao_ads124s0x_current;
  31 uint8_t         nextchan = 0;
  32 uint8_t         ao_ads124s0x_drdy;
  33
  34 static void
  35 ao_ads124s0x_start(void) {
  36         ao_spi_get_bit(AO_ADS124S0X_SPI_CS_PORT,
  37                        AO_ADS124S0X_SPI_CS_PIN,
  38                        AO_ADS124S0X_SPI_BUS,
  39                        AO_ADS124S0X_SPI_SPEED);
  40 }
  41
  42 static void
  43 ao_ads124s0x_stop(void) {
  44         ao_spi_put_bit(AO_ADS124S0X_SPI_CS_PORT,
  45                        AO_ADS124S0X_SPI_CS_PIN,
  46                        AO_ADS124S0X_SPI_BUS);
  47 }
  48
  49 /*
  50 static uint8_t
  51 ao_ads124s0x_reg_read(uint8_t addr)
  52 {
  53         uint8_t d[2];
  54
  55         d[0] = addr | AO_ADS124S0X_RREG;
  56         d[1] = 0;
  57         ao_ads124s0x_start();
  58         ao_spi_duplex(d, d, 2, AO_ADS124S0X_SPI_BUS);
  59         ao_ads124s0x_stop();
  60
  61         PRINTD(DEBUG_LOW, "read %x = %x\n", addr, d);
  62
  63         return d[1];
  64 }
  65
  66 static void
  67 ao_ads124s0x_reg_write(uint8_t addr, uint8_t value)
  68 {
  69         uint8_t d[3];
  70
  71         PRINTD(DEBUG_LOW, "write %x %x\n", addr, value);
  72         d[0] = addr | AO_ADS124S0X_WREG;
  73         d[1] = 0;
  74         d[2] = value;
  75         ao_ads124s0x_start();
  76         ao_spi_send(d, 3, AO_ADS124S0X_SPI_BUS);
  77         ao_ads124s0x_stop();
  78
  79 #if DEBUG & DEBUG_LOW
  80         d[0] = addr | AO_ADS124S0X_RREG
  81         d[1] = 0;
  82         ao_ads124s0x_start();
  83         ao_spi_duplex(d, d, 2, AO_ADS124S0X_SPI_BUS);
  84         ao_ads124s0x_stop();
  85         PRINTD(DEBUG_LOW, "readback %x %x\n", d[0], d[1]);
  86 #endif
  87 }
  88 */
  89
  90 // FIXME
  91 //      We need to be in continuous conversion mode, and use the WREG
  92 //      command to set the next conversion input while reading each
  93 //      which I don't see an example for elsewhere?
  94
  95 static void
  96 ao_ads124s0x_setup(void)
  97 {
  98         uint8_t d[20];
  99
 100         uint8_t devid = ao_ads124s0x_reg_read(AO_ADS124S0X_ID);
 101         if (devid != AO_ADS124S0X_ID_ADS124S06)
 102                 ao_panic(AO_PANIC_SELF_TEST_ADS124S0X);
 103
 104         ao_exti_setup(AO_ADS124S0x_DRDY_PORT, AO_ADS124S0X_DRDY_PIN,
 105                 AO_EXTI_MODE_FALLING|AO_EXTI_PRIORITY_HIGH,
 106                 ao_ads124s0x_isr);
 107
 108         /* run converter at 4ksps so we can scan 4 channels at 1ksps using
 109            full duplex ala datasheet section 9.5.4.3 */
 110
 111         d[0] = AO_ADS124S0X_INPMUX | AO_ADS124S0X_WREG;
 112         d[1] = 8;       /* write 8 registers starting with INPMUX */
 113         d[2] = 0x0c;    /* input mux AIN0 relative to AINCOM */
 114         d[3] = 0x00;    /* default first conversion delay, pga disabled */
 115         d[4] = 0x1e;    /* gchop disabled, internal clock, continuous
 116                            conversion, low-latency filter, 4000 SPS */
 117         d[5] = 0x00;    /* ref monitor disabled, ref buffers bypassed, ref
 118                            set to REFP0/REFN0, internal reference off */
 119         d[6] = 0x00;    /* pga otuput rail, low side power switch, excitation
 120                            current source all off */
 121         d[7] = 0xff;    /* idac1 and idac2 disconnected */
 122         d[8] = 0x00;    /* all vbias disconnected */
 123         d[9] = 0x10;    /* sys monitor off, spi timeout disabled, crc disabled,
 124                            prepending status byte disabled */
 125         ao_ads124s0x_start();
 126         ao_spi_send(d, 10, AO_ADS124S0X_SPI_BUS);
 127         ao_ads124s0x_stop();
 128
 129         /* start conversions */
 130
 131         d[0] = AO_ADS124S0X_START;
 132         ao_ads124s0x_start();
 133         ao_spi_send(d, 1, AO_ADS124S0X_SPI_BUS);
 134         ao_ads124s0x_stop();
 135 }
 136
 137 static void
 138 ao_ads124s0x(void)
 139 {
 140         uint8_t d[3], curchan;
 141
 142         ao_ads124s0x_setup();
 143
 144         ao_exti_enable(AO_ADS124S0X_DRDY_PORT, AO_ADS124S0X_DRDY_PIN);
 145
 146         for (;;) {
 147                 ao_sleep(&ao_ads124s0x_drdy);
 148
 149                 curchan = nextchan;
 150                 nextchan = (nextchan + 1) % AO_ADS124S0X_CHANNELS;
 151
 152                 d[0] = AO_ADS124S0X_INPMUX | AO_ADS124S0X_WREG;
 153                 d[1] = 1;
 154                 d[2] = nextchan << 4 | 0x0c; ;  /* relative to AINCOM */
 155                 ao_ads124s0x_start();
 156                 ao_spi_duplex(d, d, 3, AO_ADS124S0X_SPI_BUS);
 157                 ao_ads124s0x_stop();
 158
 159                 ao_ads124s0x_current.ain[curchan] =
 160                         d[0] << 16 | d[1] << 8 | d[2];
 161
 162                 // FIXME
 163                 //      If nextchan == 0, we have a complete set of inputs
 164                 //      and we need to log them somewhere
 165
 166         }
 167 }
 168
 169 void ao_ads124s0x_isr(void)
 170 {
 171         ao_wakeup(&ao_ads124s0x_drdy);
 172 }
 173
 174 static struct ao_task ao_ads124s0x_task;
 175
 176 static void
 177 ao_ads124s0x_dump(void)                 // FIXME
 178 {
 179         printf ("ADS124S0X value %d %d %d %d\n",
 180                 ao_ads124s0x_current.ain[0],
 181                 ao_ads124s0x_current.ain[1],
 182                 ao_ads124s0x_current.ain[2],
 183                 ao_ads124s0x_current.ain[3]);
 184 }
 185
 186 const struct ao_cmds ao_ads124s0x_cmds[] = {
 187         { ao_ads124s0x_dump,    "I\0Display ADS124S0X data" },
 188         { 0, NULL },
 189 };
 190
 191 void
 192 ao_ads124s0x_init(void)
 193 {
 194         ao_cmd_register(ao_ads124s0x_cmds);
 195
 196         ao_spi_init_cs(AO_ADS124S0X_SPI_CS_PORT,
 197                 (1 << AO_ADS124S0X_SPI_CS_PIN));
 198
 199         ao_add_task(&ao_ads124s0x_task, ao_ads124s0x, "ads124s0x");
 200 }