Combined Gyro-Mode

[peehrlich2]

In EV3-G there is a mode to receive Gyro-Rate & Gyro-Angle both in the same cycle.
In ev3rt you have to choose Rate Xor Angle. If you switch it is like a Reset to the Gyro-Sensor.
Is it possible to implement a combined Gyro-Mode in ev3rt?

[JakubVanek]

It should definitely be possible, although high-level wrappers are not implemented for that. Taking
https://github.com/ev3rt-git/ev3rt-hrp2-sdk/blob/16510594d83b1c50d97f868bbf920914621ecdd2/common/ev3api/src/ev3api_sensor.c#L245 as base:

• it is necessary to use GYRO_GnA in place of GYRO_RATE
• it is necessary to define a new struct that will be filled by uart_fetch_sensor_data:

struct gyro_combo_data {
    int16_t rate;
    int16_t angle;
}

• it is necessary to pass an instance of that struct to uart_fetch_sensor_data instead of the integer.

[JakubVanek]

Hi,

i have written a git patch that adds this functionality. It can be applied with git am <path to patch>:

From 8661f81fa9bc2f2221c4ca36b62f47cee0f48e46 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jakub=20Van=C4=9Bk?= <vanek.jakub4@seznam.cz>
Date: Thu, 20 Feb 2020 17:22:30 +0100
Subject: [PATCH] feat(ev3api/sensors/gyro): add support for fetching
 angle+rate

---
 common/ev3api/src/ev3api_sensor.c | 14 ++++++++++++++
 common/ev3api/src/ev3api_sensor.h | 18 ++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/common/ev3api/src/ev3api_sensor.c b/common/ev3api/src/ev3api_sensor.c
index 1cfb0eb..6495723 100644
--- a/common/ev3api/src/ev3api_sensor.c
+++ b/common/ev3api/src/ev3api_sensor.c
@@ -258,6 +258,20 @@ error_exit:
     return 0;
 }
 
+void ev3_gyro_sensor_get_angle_and_rate(sensor_port_t port, angle_rate_t *data) {
+	ER ercd;
+
+//	lazy_initialize();
+	CHECK_PORT(port);
+	CHECK_COND(ev3_sensor_get_type(port) == GYRO_SENSOR, E_OBJ);
+
+	uart_sensor_fetch_data(port, GYRO_GnA, data, sizeof(angle_rate_t));
+	return;
+
+error_exit:
+	syslog(LOG_WARNING, "%s(): ercd %d", __FUNCTION__, ercd);
+}
+
 ER ev3_gyro_sensor_reset(sensor_port_t port) {
 	ER ercd;
 
diff --git a/common/ev3api/src/ev3api_sensor.h b/common/ev3api/src/ev3api_sensor.h
index c31b907..7666e23 100644
--- a/common/ev3api/src/ev3api_sensor.h
+++ b/common/ev3api/src/ev3api_sensor.h
@@ -85,6 +85,15 @@ typedef struct {
     uint16_t b; //!< \~English Blue value  \~Japanese 青
 } rgb_raw_t;
 
+/**
+ * \~English
+ * \brief Structure for a combined angle-rate gyro state
+ */
+typedef struct {
+    int16_t angle;
+    int16_t rate;
+} angle_rate_t;
+
 /** 
  * \~English
  * \brief 	     Configure a sensor port.
@@ -211,6 +220,15 @@ int16_t ev3_gyro_sensor_get_angle(sensor_port_t port);
  */
 int16_t ev3_gyro_sensor_get_rate(sensor_port_t port);
 
+/**
+ * \~English
+ * \brief 	   Get both the angular position and the angular speed by a gyroscope sensor.
+ * \details    Always returns 0 (error log is outputted) when an invalid sensor number is specified.
+ * \param port Sensor port to be inquired
+ * \param data Combined angle and rate gyroscope data.
+ */
+void ev3_gyro_sensor_get_angle_and_rate(sensor_port_t port, angle_rate_t *data);
+
 /**
  * \~English
  * \brief 	    Reset the angular position of a gyroscope sensor to zero.
-- 
2.17.1