Which driver variables match the QE CapTouch chart
Which driver variables match the QE CapTouch chart
Background:
Some users have expressed interest in developing their own custom debug monitoring system similar to the QE tool's CapTouch Status Chart View. This article explains which variables in the driver source code correspond to each item displayed in the QE tool's CapTouch Status Chart View.
Answer:
Each item displayed in the Status Chart View of QE for Capacitive Touch (hereafter “QE tool”), and the corresponding variables in the TOUCH middleware source code is explained below.
◆ Button (Self-capacitance) / Keypad (Self-capacitance)
Status Chart View | TOUCH Middleware variable | Remarks |
Measurement Value | data[] (local variable)*1 | Temporarily stored in the local variable data[] of the RM_TOUCH_DataGet function and discarded after the function ends. |
Baseline | g_touch_button_reference[]*1 | The address is stored in binfo.p_reference in the control block*3. |
Threshold | g_touch_button_threshold[]*1 | The address is stored in binfo.p_threshold in the control block*3. |
Touch ON/OFF Difference | None | Calculated and displayed by the QE tool as “Measurement Value − Threshold Value”. |
◆ Slider (Self-capacitance)
Status Chart View | TOUCH Middleware variable | Remarks |
Touch Position | g_touch_slider_position[]*1 | Stored in sinfo.p_position in the control block*3. |
Resolution | None | Always displayed as 100. |
Threshold | g_touch_slider_threshold[]*1 | Stored in sinfo.p_threshold in the control block*3. |
◆ Wheel (Self-capacitance)
Status Chart View | TOUCH Middleware variable | Remarks |
Touch Position | g_touch_wheel_position[]*1 | Stored in winfo.p_position in the control block*3. |
Resolution | None | Always displayed as 360. |
Threshold | g_touch_wheel_threshold[]*1 | Stored in winfo.p_threshold in the control block*3. |
◆ Keypad (Mutual-capacitance)
Status Chart View | TOUCH Middleware variable | Remarks |
Measurement Value | sensor_mutual_val (local variable)*2 | Temporarily stored in the local variable sensor_mutual_val of the RM_TOUCH_DataGet function and discarded after the function ends. |
Baseline | g_touch_button_reference[]*1 | Stored in binfo.p_reference in the control block*3. |
Threshold | g_touch_button_threshold[]*1 | Stored in binfo.p_threshold in the control block*3. |
Touch ON/OFF Difference | None | Calculated and displayed by the QE tool as “Measurement Value − Threshold Value”. |
Note1: The QE tool doesn't monitor this variable directly. Instead, it monitors a global variable g_touch_monitor_buf[] that contains a copy for the data. For more details, refer to the rm_touch.c implemetion.
Note2: This variable is not copied to g_touch_monitor_buf[]. Instead, a local variable data[], which contains the primary and secondary measurement values, is copied to it. The QE tool then calcurates the measurement value as "secondly measurement value - primary measurement value".
Note3: The “control block” refers to the global variable g_qe_touch_ctrl_<configuration_name> generated by the QE tool, which is of type touch_instance_ctrl_t.