Note
This Bricklet is currently in the prototype stage and the software/hardware as well as the documentation is in an incomplete state.
This is the description of the C/C++ API bindings for the Industrial Dual Analog In Bricklet. General information and technical specifications for the Industrial Dual Analog In Bricklet are summarized in its hardware description.
An installation guide for the C/C++ API bindings is part of their general description.
The example code below is Public Domain (CC0 1.0).
Every function of the C/C++ bindings returns an integer which describes an error code. Data returned from the device, when a getter is called, is handled via call by reference. These parameters are labeled with the ret_ prefix.
Possible error codes are:
as defined in ip_connection.h.
All functions listed below are thread-safe.
The Bricklet has two input channel. Functions that are related directly to a channel have a channel parameter to specify one of the two channels. Valid values for the channel parameter are 0 and 1.
Creates the device object industrial_dual_analog_in with the unique device ID uid and adds it to the IPConnection ipcon:
IndustrialDualAnalogIn industrial_dual_analog_in;
industrial_dual_analog_in_create(&industrial_dual_analog_in, "YOUR_DEVICE_UID", &ipcon);
This device object can be used after the IP connection has been connected (see examples above).
Removes the device object industrial_dual_analog_in from its IPConnection and destroys it. The device object cannot be used anymore afterwards.
Returns the voltage for the given channel in mV.
If you want to get the voltage periodically, it is recommended to use the callback INDUSTRIAL_DUAL_ANALOG_IN_CALLBACK_VOLTAGE and set the period with industrial_dual_analog_in_set_voltage_callback_period().
Sets the sample rate. The sample rate can be between 1 sample per second and 976 samples per second. Decreasing the sample rate will also decrease the noise on the data.
The following defines are available for this function:
Returns the sample rate as set by industrial_dual_analog_in_set_sample_rate().
The following defines are available for this function:
Sets offset and gain of MCP3911 internal calibration registers.
See MCP3911 datasheet 7.7 and 7.8. The Industrial Dual Analog In Bricklet is already factory calibrated by Tinkerforge. It should not be necessary for you to use this function
Returns the calibration as set by industrial_dual_analog_in_set_calibration().
Returns the ADC values as given by the MCP3911 IC. This function is needed for proper calibration, see industrial_dual_analog_in_set_calibration().
Returns the version of the API definition (major, minor, revision) implemented by this API bindings. This is neither the release version of this API bindings nor does it tell you anything about the represented Brick or Bricklet.
Returns the response expected flag for the function specified by the function ID parameter. It is true if the function is expected to send a response, false otherwise.
For getter functions this is enabled by default and cannot be disabled, because those functions will always send a response. For callback configuration functions it is enabled by default too, but can be disabled by industrial_dual_analog_in_set_response_expected(). For setter functions it is disabled by default and can be enabled.
Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.
See industrial_dual_analog_in_set_response_expected() for the list of function ID defines available for this function.
Changes the response expected flag of the function specified by the function ID parameter. This flag can only be changed for setter (default value: false) and callback configuration functions (default value: true). For getter functions it is always enabled and callbacks it is always disabled.
Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.
The following function ID defines are available for this function:
Changes the response expected flag for all setter and callback configuration functions of this device at once.
Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.
The position can be 'a', 'b', 'c' or 'd'.
The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.
Registers a callback with ID id to the function callback. The user_data will be given as a parameter of the callback.
The available IDs with corresponding function signatures are listed below.
Sets the period in ms with which the INDUSTRIAL_DUAL_ANALOG_IN_CALLBACK_VOLTAGE callback is triggered periodically for the given channel. A value of 0 turns the callback off.
INDUSTRIAL_DUAL_ANALOG_IN_CALLBACK_VOLTAGE is only triggered if the voltage has changed since the last triggering.
The default value is 0.
Returns the period as set by industrial_dual_analog_in_set_voltage_callback_period().
Sets the thresholds for the INDUSTRIAL_DUAL_ANALOG_IN_CALLBACK_VOLTAGE_REACHED callback for the given channel.
The following options are possible:
Option | Description |
---|---|
'x' | Callback is turned off |
'o' | Callback is triggered when the voltage is outside the min and max values |
'i' | Callback is triggered when the voltage is inside the min and max values |
'<' | Callback is triggered when the voltage is smaller than the min value (max is ignored) |
'>' | Callback is triggered when the voltage is greater than the min value (max is ignored) |
The default value is ('x', 0, 0).
The following defines are available for this function:
Returns the threshold as set by industrial_dual_analog_in_set_voltage_callback_threshold().
The following defines are available for this function:
Sets the period in ms with which the threshold callback
is triggered, if the threshold
keeps being reached.
The default value is 100.
Returns the debounce period as set by industrial_dual_analog_in_set_debounce_period().
Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the industrial_dual_analog_in_register_callback() function. The parameters consist of the device object, the callback ID, the callback function and optional user data:
void my_callback(int p, void *user_data) { printf("parameter: %d\n", p); } industrial_dual_analog_in_register_callback(&industrial_dual_analog_in, INDUSTRIAL_DUAL_ANALOG_IN_CALLBACK_EXAMPLE, (void *)my_callback, NULL);
The available constants with corresponding callback function signatures are described below.
Note
Using callbacks for recurring events is always preferred compared to using getters. It will use less USB bandwidth and the latency will be a lot better, since there is no round trip time.
void callback(uint8_t channel, int32_t voltage, void *user_data)
This callback is triggered periodically with the period that is set by industrial_dual_analog_in_set_voltage_callback_period(). The parameter is the voltage of the channel.
INDUSTRIAL_DUAL_ANALOG_IN_CALLBACK_VOLTAGE is only triggered if the voltage has changed since the last triggering.
void callback(uint8_t channel, int32_t voltage, void *user_data)
This callback is triggered when the threshold as set by industrial_dual_analog_in_set_voltage_callback_threshold() is reached. The parameter is the voltage of the channel.
If the threshold keeps being reached, the callback is triggered periodically with the period as set by industrial_dual_analog_in_set_debounce_period().
This constant is used to identify a Industrial Dual Analog In Bricklet.
The industrial_dual_analog_in_get_identity() function and the IPCON_CALLBACK_ENUMERATE callback of the IP Connection have a device_identifier parameter to specify the Brick's or Bricklet's type.