2 * Copyright © 2019 Bdale Garbee <bdale@gag.com>
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.
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.
17 #include "ao_ads124s0x.h"
25 #define PRINTD(l, ...) do { if (DEBUG & (l)) { printf ("\r%5u %s: ", ao_tick_count, __func__); printf(__VA_ARGS__); flush(); } } while(0)
30 struct ao_ads124s0x_sample ao_ads124s0x_current;
32 uint8_t ao_ads124s0x_drdy;
35 ao_ads124s0x_start(void) {
36 ao_spi_get_bit(AO_ADS124S0X_SPI_CS_PORT,
37 AO_ADS124S0X_SPI_CS_PIN,
39 AO_ADS124S0X_SPI_SPEED);
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);
51 ao_ads124s0x_reg_read(uint8_t addr)
55 d[0] = addr | AO_ADS124S0X_RREG;
58 ao_spi_duplex(d, d, 2, AO_ADS124S0X_SPI_BUS);
61 PRINTD(DEBUG_LOW, "read %x = %x\n", addr, d);
67 ao_ads124s0x_reg_write(uint8_t addr, uint8_t value)
71 PRINTD(DEBUG_LOW, "write %x %x\n", addr, value);
72 d[0] = addr | AO_ADS124S0X_WREG;
76 ao_spi_send(d, 3, AO_ADS124S0X_SPI_BUS);
80 d[0] = addr | AO_ADS124S0X_RREG
83 ao_spi_duplex(d, d, 2, AO_ADS124S0X_SPI_BUS);
85 PRINTD(DEBUG_LOW, "readback %x %x\n", d[0], d[1]);
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?
96 ao_ads124s0x_setup(void)
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);
104 ao_exti_setup(AO_ADS124S0x_DRDY_PORT, AO_ADS124S0X_DRDY_PIN,
105 AO_EXTI_MODE_FALLING|AO_EXTI_PRIORITY_HIGH,
108 /* run converter at 4ksps so we can scan 4 channels at 1ksps using
109 full duplex ala datasheet section 9.5.4.3 */
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);
129 /* start conversions */
131 d[0] = AO_ADS124S0X_START;
132 ao_ads124s0x_start();
133 ao_spi_send(d, 1, AO_ADS124S0X_SPI_BUS);
140 uint8_t d[3], curchan;
142 ao_ads124s0x_setup();
144 ao_exti_enable(AO_ADS124S0X_DRDY_PORT, AO_ADS124S0X_DRDY_PIN);
147 ao_sleep(&ao_ads124s0x_drdy);
150 nextchan = (nextchan + 1) % AO_ADS124S0X_CHANNELS;
152 d[0] = AO_ADS124S0X_INPMUX | AO_ADS124S0X_WREG;
154 d[2] = nextchan << 4 | 0x0c; ; /* relative to AINCOM */
155 ao_ads124s0x_start();
156 ao_spi_duplex(d, d, 3, AO_ADS124S0X_SPI_BUS);
159 ao_ads124s0x_current.ain[curchan] =
160 d[0] << 16 | d[1] << 8 | d[2];
163 // If nextchan == 0, we have a complete set of inputs
164 // and we need to log them somewhere
169 void ao_ads124s0x_isr(void)
171 ao_wakeup(&ao_ads124s0x_drdy);
174 static struct ao_task ao_ads124s0x_task;
177 ao_ads124s0x_dump(void) // FIXME
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]);
186 const struct ao_cmds ao_ads124s0x_cmds[] = {
187 { ao_ads124s0x_dump, "I\0Display ADS124S0X data" },
192 ao_ads124s0x_init(void)
194 ao_cmd_register(ao_ads124s0x_cmds);
196 ao_spi_init_cs(AO_ADS124S0X_SPI_CS_PORT,
197 (1 << AO_ADS124S0X_SPI_CS_PIN));
199 ao_add_task(&ao_ads124s0x_task, ao_ads124s0x, "ads124s0x");