altos: first draft of driver for ADS1256 ADC from TI

diff --git a/src/drivers/ao_ads1256.c b/src/drivers/ao_ads1256.c
new file mode 100644 (file)
index 0000000..8a87f7f
--- /dev/null
+++ b/src/drivers/ao_ads1256.c
@@ -0,0 +1,217 @@
+/*
+ * Copyright © 2019 Bdale Garbee <bdale@gag.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#include <ao.h>
+#include <ao_exti.h>
+#include "ao_ads1256.h"
+
+#define DEBUG_LOW      1
+#define DEBUG_HIGH     2
+
+#define DEBUG          0
+
+#if DEBUG
+#define PRINTD(l, ...) do { if (DEBUG & (l)) { printf ("\r%5u %s: ", ao_tick_count, __func__); printf(__VA_ARGS__); flush(); } } while(0)
+#else
+#define PRINTD(l,...)
+#endif
+
+struct ao_ads1256_sample       ao_ads1256_current;
+uint8_t                nextchan = 0;
+uint8_t                ao_ads1256_drdy;
+
+static void
+ao_ads1256_start(void) {
+       ao_spi_get_bit(AO_ADS1256_SPI_CS_PORT,
+                      AO_ADS1256_SPI_CS_PIN,
+                      AO_ADS1256_SPI_BUS,
+                      AO_ADS1256_SPI_SPEED);
+}
+
+static void
+ao_ads1256_stop(void) {
+       ao_spi_put_bit(AO_ADS1256_SPI_CS_PORT,
+                      AO_ADS1256_SPI_CS_PIN,
+                      AO_ADS1256_SPI_BUS);
+}
+
+/*
+static uint8_t
+ao_ads1256_reg_read(uint8_t addr)
+{
+       uint8_t d[2];
+
+       d[0] = addr | AO_ADS1256_RREG;
+       d[1] = 0;                       
+       ao_ads1256_start();
+       ao_spi_send(d, 2, AO_ADS1256_SPI_BUS);
+       d[0] = 0;
+       ao_spi_recv(d, 1, AO_ADS1256_SPI_BUS);
+       ao_ads1256_stop();
+
+       PRINTD(DEBUG_LOW, "read %x = %x\n", addr, d[0]);
+
+       return d[0];
+}
+*/
+/*
+static void
+ao_ads1256_reg_write(uint8_t addr, uint8_t value)
+{
+       uint8_t d[3];
+
+       PRINTD(DEBUG_LOW, "write %x %x\n", addr, value);
+       d[0] = addr | AO_ADS1256_WREG;
+       d[1] = 0;                       
+       d[2] = value;
+       ao_ads1256_start();
+       ao_spi_send(d, 3, AO_ADS1256_SPI_BUS);
+       ao_ads1256_stop();
+
+}
+*/
+
+static void 
+ao_ads1256_isr(void)
+{
+       ao_ads1256_drdy = 1;
+       ao_wakeup(&ao_ads1256_drdy);
+}
+
+static void
+ao_ads1256_setup(void)
+{
+       uint8_t d[20];
+
+       ao_delay(1);
+
+       /* set up interrupt on DRDY going low */
+
+       ao_exti_setup(AO_ADS1256_DRDY_PORT, AO_ADS1256_DRDY_PIN,
+               AO_EXTI_MODE_FALLING|AO_EXTI_PRIORITY_HIGH,
+               ao_ads1256_isr);
+
+       /* reset the chip */
+
+//     d[0] = AO_ADS1256_RESET;
+//     ao_ads1256_start();
+//     ao_spi_send(d, 1, AO_ADS1256_SPI_BUS);
+//     ao_ads1256_stop();
+
+       /* read status register */
+
+       d[0] = AO_ADS1256_STATUS | AO_ADS1256_RREG;
+       ao_ads1256_start();
+       ao_spi_send(d, 1, AO_ADS1256_SPI_BUS);
+       d[0] = 0;
+       ao_spi_send(d, 1, AO_ADS1256_SPI_BUS);
+       ao_spi_recv(d, 1, AO_ADS1256_SPI_BUS);
+       ao_ads1256_stop();
+
+       printf ("ADS1256 status 0x%x\n", d[0]);
+
+       /* write configuration registers, tell converter to start working */
+
+       d[0] = AO_ADS1256_STATUS | AO_ADS1256_WREG;
+       d[1] = 4;       /* write 5 registers starting with STATUS */
+       d[2] = 0x00;    /* msb first, auto-cal off, analog buffer disabled */
+       d[3] = 0x08;    /* mux AIN0 relative to AINCOM */
+       d[4] = 0x20;    /* clock out = fclkin, sensor detect off, pga gain 1 */
+       d[5] = 0xf0;    /* data rate 30,000 SPS */
+       d[6] = 0xf0;    /* all gpio pins are inputs */
+       d[7] = AO_ADS1256_SYNC;
+       d[8] = AO_ADS1256_WAKEUP;
+       ao_ads1256_start();
+       ao_spi_send(d, 9, AO_ADS1256_SPI_BUS);
+       ao_ads1256_stop();
+}
+
+static void
+ao_ads1256(void)
+{
+       uint8_t d[6], curchan;
+
+       ao_ads1256_setup();
+
+       ao_exti_enable(AO_ADS1256_DRDY_PORT, AO_ADS1256_DRDY_PIN);
+
+       for (;;) {
+               ao_arch_block_interrupts();
+               ao_ads1256_drdy = 0;
+               while (ao_ads1256_drdy == 0)
+                       ao_sleep(&ao_ads1256_drdy);
+               ao_arch_release_interrupts();
+
+               curchan = nextchan;
+               nextchan = (nextchan + 1) % AO_ADS1256_CHANNELS;
+
+               d[0] = AO_ADS1256_MUX | AO_ADS1256_WREG;
+               d[1] = 0;                       /* write one register */
+               d[2] = nextchan << 4 | 0x08; ;  /* relative to AINCOM */
+               d[3] = AO_ADS1256_SYNC;
+               d[4] = AO_ADS1256_WAKEUP;
+               d[5] = AO_ADS1256_RDATA;
+               ao_ads1256_start();
+               ao_spi_send(d, 6, AO_ADS1256_SPI_BUS);
+//             ao_delay(1);
+               ao_spi_recv(d, 3, AO_ADS1256_SPI_BUS);
+               ao_ads1256_stop();
+
+               ao_ads1256_current.ain[curchan] = 
+                       d[0] << 16 | d[1] << 8 | d[2];
+
+               // FIXME
+               //      If nextchan == 0, we have a complete set of inputs
+               //      and we need to log them somewhere
+
+               ao_ads1256_drdy = 0;
+       }
+}
+
+static struct ao_task ao_ads1256_task;
+
+static void
+ao_ads1256_dump(void)  
+{
+       static int done;
+
+       if (!done) {
+               done = 1;
+               ao_add_task(&ao_ads1256_task, ao_ads1256, "ads1256");
+       }
+               
+       printf ("ADS1256 value %d %d %d %d\n",
+               ao_ads1256_current.ain[0],
+               ao_ads1256_current.ain[1],
+               ao_ads1256_current.ain[2],
+               ao_ads1256_current.ain[3]);
+}
+
+const struct ao_cmds ao_ads1256_cmds[] = {
+       { ao_ads1256_dump,      "D\0Display ADS1256 data" },
+       { 0, NULL },
+};
+
+void
+ao_ads1256_init(void)
+{
+       ao_cmd_register(ao_ads1256_cmds);
+
+//     ao_enable_output(AO_ADS1256_RESET_PORT, AO_ADS1256_RESET_PIN, 0);
+
+       ao_spi_init_cs(AO_ADS1256_SPI_CS_PORT, 
+               (1 << AO_ADS1256_SPI_CS_PIN));
+
+//     ao_add_task(&ao_ads1256_task, ao_ads1256, "ads1256");
+}

diff --git a/src/drivers/ao_ads1256.h b/src/drivers/ao_ads1256.h
new file mode 100644 (file)
index 0000000..4413925
--- /dev/null
+++ b/src/drivers/ao_ads1256.h
@@ -0,0 +1,57 @@
+/*
+ * Copyright © 2019 Bdale Garbee <bdale@gag.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#ifndef _AO_ADS1256_H_
+#define _AO_ADS1256_H_
+
+/* commands */
+#define AO_ADS1256_WAKEUP              0x00
+#define AO_ADS1256_RDATA               0x01
+#define AO_ADS1256_RDATAC              0x03
+#define AO_ADS1256_SDATAC              0x0f
+#define AO_ADS1256_RREG                        0x10
+#define AO_ADS1256_WREG                        0x50
+#define AO_ADS1256_SELFCAL             0xf0
+#define AO_ADS1256_SELFOCAL            0xf1
+#define AO_ADS1256_SELFGCAL            0xf2
+#define AO_ADS1256_SYSOCAL             0xf3
+#define AO_ADS1256_SYSGCAL             0xf4
+#define AO_ADS1256_SYNC                        0xfc
+#define AO_ADS1256_STANDBY             0xfd
+#define AO_ADS1256_RESET               0xfe
+#define AO_ADS1256_WAKEUP2             0xff
+
+/* register map */
+#define AO_ADS1256_STATUS      0x00
+#define AO_ADS1256_MUX         0x01
+#define AO_ADS1256_ADCON       0x02
+#define AO_ADS1256_DRATE       0x03
+#define AO_ADS1256_IO          0x04
+#define AO_ADS1256_OFC0                0x05
+#define AO_ADS1256_OFC1                0x06
+#define AO_ADS1256_OFC2                0x07
+#define AO_ADS1256_FSC0                0x08
+#define AO_ADS1256_FSC1                0x09
+#define AO_ADS1256_FSC2                0x0a
+
+struct ao_ads1256_sample {
+       int32_t ain[AO_ADS1256_CHANNELS];
+};
+
+extern struct ao_ads1256_sample        ao_ads1256_current;
+
+void
+ao_ads1256_init(void);
+
+#endif /* _AO_ADS1256_H_ */