Chirp I2C Soil moisture sensors support

diff --git a/extdrv/chirp.c b/extdrv/chirp.c
new file mode 100644 (file)
index 0000000..41da414
--- /dev/null
+++ b/extdrv/chirp.c
@@ -0,0 +1,159 @@
+/****************************************************************************
+ *   extdrv/chirp.c
+ *
+ *
+ * Copyright 2017 Nathael Pajani <nathael.pajani@ed3l.fr>
+ *
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *************************************************************************** */
+
+
+#include "core/system.h"
+#include "lib/errno.h"
+#include "drivers/i2c.h"
+#include "extdrv/chirp.h"
+#include "lib/utils.h"
+
+/***************************************************************************** */
+/*          Support for CHIRP101 temperature sensors from Texas Instrument       */
+/***************************************************************************** */
+/* This driver is made for the CHIRP101 version of the chip, though there's few
+ * diferences between the CHIRP100 and CHIRP101 version.
+ * This driver does not handle the SMBus Alert command.
+ */
+
+
+enum chirp_internal_reg_numbers {
+       CHIRP_REG_CAP = 0,
+       CHIRP_REG_LIGHT_REQ = 3,
+       CHIRP_REG_LIGHT = 4,
+       CHIRP_REG_TEMPERATURE = 5,
+       CHIRP_REG_RESET = 6,
+};
+
+
+
+int chirp_probe_sensor(struct chirp_sensor_config* conf)
+{
+       char cmd_buf = (conf->addr | I2C_READ_BIT);
+
+       /* Did we already probe the sensor ? */
+       if (conf->probe_ok != 1) {
+               conf->probe_ok = i2c_read(conf->bus_num, &cmd_buf, 1, NULL, NULL, 0);
+       }
+       return conf->probe_ok;
+}
+
+
+
+#define CMD_BUF_SIZE 3
+int chirp_sensor_read(struct chirp_sensor_config* conf, uint8_t reg)
+{
+       int ret = 0;
+       uint16_t val = 0;
+       char cmd_buf[CMD_BUF_SIZE] = { conf->addr, 0, (conf->addr | I2C_READ_BIT), };
+       char ctrl_buf[CMD_BUF_SIZE] = { I2C_CONT, I2C_DO_REPEATED_START, I2C_CONT, };
+
+       if (chirp_probe_sensor(conf) != 1) {
+               return -ENODEV;
+       }
+       cmd_buf[1] = reg;
+
+       ret = i2c_read(conf->bus_num, cmd_buf, CMD_BUF_SIZE, ctrl_buf, (char*)&val, 2);
+
+       /* Swap to our endianness */
+       val = (uint16_t)ntohs(val);
+
+       if (ret != 2) {
+               conf->probe_ok = 0;
+               return ret;
+       }
+
+       return (int)val;
+}
+
+int chirp_sensor_write(struct chirp_sensor_config* conf, uint8_t val)
+{
+       int ret = 0;
+       char cmd[CMD_BUF_SIZE] = { conf->addr, };
+
+       if (chirp_probe_sensor(conf) != 1) {
+               return -ENODEV;
+       }
+
+       cmd[1] = val;
+       ret = i2c_write(conf->bus_num, cmd, 2, NULL);
+
+       return ret;
+}
+
+
+
+
+/* Capacitance Read
+ * Performs a non-blocking read of the capacitance from the sensor.
+ * Return value(s):
+ *   Upon successfull completion, returns the capacitance read (uint16_t).
+ *   On error, returns a negative integer equivalent to errors from glibc.
+ */
+int chirp_sensor_cap_read(struct chirp_sensor_config* conf)
+{
+       return chirp_sensor_read(conf, CHIRP_REG_CAP);
+}
+
+
+/* Temp Read
+ * Performs a non-blocking read of the temperature from the sensor.
+ * Return value(s):
+ *   Upon successfull completion, returns the temperature read (uint16_t).
+ *   On error, returns a negative integer equivalent to errors from glibc.
+ */
+int chirp_sensor_temp_read(struct chirp_sensor_config* conf)
+{
+       return chirp_sensor_read(conf, CHIRP_REG_TEMPERATURE);
+}
+
+
+/* Start a conversion of the light sensor. */
+int chirp_sensor_start_light_conversion(struct chirp_sensor_config* conf)
+{
+       return chirp_sensor_write(conf, CHIRP_REG_LIGHT_REQ);
+}
+
+/* Light Read
+ * Performs a non-blocking read of the light from the sensor.
+ * Return value(s):
+ *   Upon successfull completion, returns the ambiant light read (uint16_t).
+ *   On error, returns a negative integer equivalent to errors from glibc.
+ */
+int chirp_sensor_light_read(struct chirp_sensor_config* conf)
+{
+       return chirp_sensor_read(conf, CHIRP_REG_LIGHT);
+}
+
+
+
+/* Sensor reset
+ * Return value:
+ *   Upon successfull completion, returns 2. On error, returns a negative integer
+ *   equivalent to errors from glibc.
+ */
+int chirp_reset(struct chirp_sensor_config* conf)
+{
+       return chirp_sensor_write(conf, CHIRP_REG_RESET);
+}
+
+

diff --git a/include/extdrv/chirp.h b/include/extdrv/chirp.h
new file mode 100644 (file)
index 0000000..a566402
--- /dev/null
+++ b/include/extdrv/chirp.h
@@ -0,0 +1,87 @@
+/****************************************************************************
+ *   extdrv/chirp.h
+ *
+ *
+ * Copyright 2017 Nathael Pajani <nathael.pajani@ed3l.fr>
+ *
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *************************************************************************** */
+
+#ifndef EXTDRV_CHIRP_H
+#define EXTDRV_CHIRP_H
+
+#include "lib/stdint.h"
+
+
+/***************************************************************************** */
+/*          Support for chirp sensor from miceuz (twitter.com/miceuz)          */
+/*                https://wemakethings.net/chirp/                              */
+/***************************************************************************** */
+
+
+struct chirp_sensor_config {
+       uint8_t addr;
+       uint8_t bus_num;
+       uint8_t probe_ok;
+};
+
+
+/* Check the sensor presence, return 1 if found
+ * This is a basic check, it could be anything with the same address ...
+ */
+int chirp_probe_sensor(struct chirp_sensor_config* conf);
+
+
+/* Capacitance Read
+ * Performs a non-blocking read of the capacitance from the sensor.
+ * Return value(s):
+ *   Upon successfull completion, returns the capacitance read (uint16_t).
+ *   On error, returns a negative integer equivalent to errors from glibc.
+ */
+int chirp_sensor_cap_read(struct chirp_sensor_config* conf);
+
+/* Temp Read
+ * Performs a non-blocking read of the temperature from the sensor.
+ * Return value(s):
+ *   Upon successfull completion, returns the temperature read (uint16_t).
+ *   On error, returns a negative integer equivalent to errors from glibc.
+ */
+int chirp_sensor_temp_read(struct chirp_sensor_config* conf);
+
+
+/* Start a conversion of the light sensor. */
+int chirp_sensor_start_light_conversion(struct chirp_sensor_config* conf);
+
+/* Light Read
+ * Performs a non-blocking read of the light from the sensor.
+ * Return value(s):
+ *   Upon successfull completion, returns the ambiant light read (uint16_t).
+ *   On error, returns a negative integer equivalent to errors from glibc.
+ */
+int chirp_sensor_light_read(struct chirp_sensor_config* conf);
+
+
+
+/* Sensor reset
+ * Return value:
+ *   Upon successfull completion, returns 2. On error, returns a negative integer
+ *   equivalent to errors from glibc.
+ */
+int chirp_reset(struct chirp_sensor_config* conf);
+
+
+#endif /* EXTDRV_TEMP_H */
+