git.gag.com Git - fw/altos/blob - src/drivers/ao_ads1256.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_ads1256.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_ads1256_sample        ao_ads1256_current;
  31 uint8_t         nextchan = 0;
  32 uint8_t         ao_ads1256_drdy;
  33
  34 static void
  35 ao_ads1256_start(void) {
  36         ao_spi_get_bit(AO_ADS1256_SPI_CS_PORT,
  37                        AO_ADS1256_SPI_CS_PIN,
  38                        AO_ADS1256_SPI_BUS,
  39                        AO_ADS1256_SPI_SPEED);
  40 }
  41
  42 static void
  43 ao_ads1256_stop(void) {
  44         ao_spi_put_bit(AO_ADS1256_SPI_CS_PORT,
  45                        AO_ADS1256_SPI_CS_PIN,
  46                        AO_ADS1256_SPI_BUS);
  47 }
  48
  49
  50 static uint8_t
  51 ao_ads1256_reg_read(uint8_t addr)
  52 {
  53         uint8_t d[2];
  54
  55         d[0] = addr | AO_ADS1256_RREG;
  56         d[1] = 0;
  57         ao_ads1256_start();
  58         ao_spi_send(d, 2, AO_ADS1256_SPI_BUS);
  59         d[0] = 0;
  60         ao_spi_recv(d, 1, AO_ADS1256_SPI_BUS);
  61         ao_ads1256_stop();
  62
  63         PRINTD(DEBUG_LOW, "read %x = %x\n", addr, d[0]);
  64
  65         return d[0];
  66 }
  67
  68 /*
  69 static void
  70 ao_ads1256_reg_write(uint8_t addr, uint8_t value)
  71 {
  72         uint8_t d[3];
  73
  74         PRINTD(DEBUG_LOW, "write %x %x\n", addr, value);
  75         d[0] = addr | AO_ADS1256_WREG;
  76         d[1] = 0;
  77         d[2] = value;
  78         ao_ads1256_start();
  79         ao_spi_send(d, 3, AO_ADS1256_SPI_BUS);
  80         ao_ads1256_stop();
  81
  82 }
  83 */
  84
  85 static void
  86 ao_ads1256_isr(void)
  87 {
  88         ao_ads1256_drdy = 1;
  89         ao_wakeup(&ao_ads1256_drdy);
  90 }
  91
  92 static void
  93 ao_ads1256_setup(void)
  94 {
  95         uint8_t d[20];
  96
  97         ao_delay(1);
  98
  99         /* set up interrupt on DRDY going low */
 100
 101         ao_exti_setup(AO_ADS1256_DRDY_PORT, AO_ADS1256_DRDY_PIN,
 102                 AO_EXTI_MODE_FALLING|AO_EXTI_PRIORITY_HIGH,
 103                 ao_ads1256_isr);
 104
 105         /* read status register and confirm device id matches */
 106
 107         uint8_t devid = ao_ads1256_reg_read(AO_ADS1256_STATUS) >> 4;
 108         if (devid != AO_ADS1256_ID_ADS1256)
 109                 ao_panic(AO_PANIC_SELF_TEST_ADS);
 110
 111         /* write configuration registers, tell converter to start working */
 112
 113         d[0] = AO_ADS1256_STATUS | AO_ADS1256_WREG;
 114         d[1] = 4;       /* write 5 registers starting with STATUS */
 115         d[2] = 0x00;    /* msb first, auto-cal off, analog buffer disabled */
 116         d[3] = 0x08;    /* mux AIN0 relative to AINCOM */
 117         d[4] = 0x20;    /* clock out = fclkin, sensor detect off, pga gain 1 */
 118         d[5] = 0xf0;    /* data rate 7500 SPS */
 119         d[6] = 0xf0;    /* all gpio pins are inputs */
 120         d[7] = AO_ADS1256_SYNC;
 121         d[8] = AO_ADS1256_WAKEUP;
 122         ao_ads1256_start();
 123         ao_spi_send(d, 9, AO_ADS1256_SPI_BUS);
 124         ao_ads1256_stop();
 125 }
 126
 127 static void
 128 ao_ads1256(void)
 129 {
 130         uint8_t d[6], curchan;
 131
 132         ao_ads1256_setup();
 133
 134         ao_exti_enable(AO_ADS1256_DRDY_PORT, AO_ADS1256_DRDY_PIN);
 135
 136         for (;;) {
 137                 ao_arch_block_interrupts();
 138                 ao_ads1256_drdy = 0;
 139                 while (ao_ads1256_drdy == 0)
 140                         ao_sleep(&ao_ads1256_drdy);
 141                 ao_arch_release_interrupts();
 142
 143                 curchan = nextchan;
 144                 nextchan = (nextchan + 1) % AO_ADS1256_CHANNELS;
 145
 146                 d[0] = AO_ADS1256_MUX | AO_ADS1256_WREG;
 147                 d[1] = 0;                       /* write one register */
 148                 d[2] = nextchan << 4 | 0x08; ;  /* relative to AINCOM */
 149                 d[3] = AO_ADS1256_SYNC;
 150                 d[4] = AO_ADS1256_WAKEUP;
 151                 d[5] = AO_ADS1256_RDATA;
 152                 ao_ads1256_start();
 153                 ao_spi_send(d, 6, AO_ADS1256_SPI_BUS);
 154                 ao_spi_recv(d, 3, AO_ADS1256_SPI_BUS);
 155                 ao_ads1256_stop();
 156
 157                 ao_ads1256_current.ain[curchan] =
 158                         d[0] << 16 | d[1] << 8 | d[2];
 159
 160                 // FIXME
 161                 //      If nextchan == 0, we have a complete set of inputs
 162                 //      and we need to log them somewhere
 163
 164                 ao_ads1256_drdy = 0;
 165         }
 166 }
 167
 168 static struct ao_task ao_ads1256_task;
 169
 170 static void
 171 ao_ads1256_dump(void)
 172 {
 173         static int done;
 174
 175         if (!done) {
 176                 done = 1;
 177                 ao_add_task(&ao_ads1256_task, ao_ads1256, "ads1256");
 178         }
 179
 180         printf ("ADS1256 value 0x%x 0x%x 0x%x 0x%x\n",
 181                 ao_ads1256_current.ain[0],
 182                 ao_ads1256_current.ain[1],
 183                 ao_ads1256_current.ain[2],
 184                 ao_ads1256_current.ain[3]);
 185 }
 186
 187 const struct ao_cmds ao_ads1256_cmds[] = {
 188         { ao_ads1256_dump,      "D\0Display ADS1256 data" },
 189         { 0, NULL },
 190 };
 191
 192 void
 193 ao_ads1256_init(void)
 194 {
 195         ao_cmd_register(ao_ads1256_cmds);
 196
 197 //      ao_enable_output(AO_ADS1256_RESET_PORT, AO_ADS1256_RESET_PIN, 0);
 198
 199         ao_spi_init_cs(AO_ADS1256_SPI_CS_PORT,
 200                 (1 << AO_ADS1256_SPI_CS_PIN));
 201
 202 //      ao_add_task(&ao_ads1256_task, ao_ads1256, "ads1256");
 203 }