Objective
The following step-by-step guide shows you how to create a low-power sensor project and configure low-power parameters in Atmel START. This project is generated using the ATtiny3217 Xplained Pro along with the QT7 Xplained Pro Extension Kit.| Low-power with event system | The CPU is put into Standby mode and a periodic RTC/Timer event triggers a touch sensor measurement on the configured low power sensor. In this mode, only a single button or lump sensor (a single group of buttons/sliders/wheels) can be configured as a low-power wake-up sensor. This is also called an Event-Driven Low-Power mode. |
| Low-power without event system | A periodic RTC/Timer interrupt wakes up the CPU from Standby mode to trigger a touch measurement on the configured low-power sensor. In this mode, a combination of buttons/lump sensors/slider or wheel sensors can be configured as low-power wake-up sensors. This is also called Software-Driven Low-Power mode. |
| Lump | A lump is a group of two or more buttons or slider or wheel in any combination. In addition, a lump can be configured as low-power with or without an event system. |
Materials
Hardware Tools
| Tool | About | Purchase |
|---|---|---|
 ATtiny3217 Xplained Pro
ATTINY3217-XPRO |
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QT7 Xplained Pro Extension Kit
ATQT7-XPRO |
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Software Tools
| Tool | About | Installers |
Installation
Instructions |
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|---|---|---|---|---|---|
| Windows | Linux | Mac OSX | |||
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Atmel® START (ASF4)
Integrated Software Framework |
| Web Based | |||
Procedure
Creating a Low Power Sensor
1
QT7 Configuration
Add the QT7 sensor configuration (i.e., two buttons, one slider) to the QTouch® device canvas page.
Refer to the "Generate User Board Touch Project" page for more details on how to create an Atmel START Project.
Event-Driven Low-Power
1
Selecting Low-Power Sensor
Click on the desired sensor to be selected as the low-power sensor and click Configure as low power.
Configure as low power is also visible if you right click on sensor.
After configuring the button as a low-power sensor, the button turns green.
If a button is configured as a low-power sensor using the steps above, it is configured as Event-Driven Low-Power mode. If a slider or wheel is configured as low-power, then Software-Driven Low-Power mode is configured.
2
Configuring Lump as Low-Power
Select the three sensors and click Create Lump. The lump sensor will be displayed in the bottom of the page.
- Click on Lump sensor and click Configure as low power to configure this lump as a low-power.
- By hovering the mouse over the lump, all the lumped sensors will be highlighted in yellow.
The configuration parameters below are based on Event-Driven Low-Power mode.
The "Configuring all unused pins as output low" checkbox is optional and only to be selected after configuring all PTC, UART lines, etc.
- The sensor saturation must be taken care of while handling the lumps.
- The lump sensor threshold should be the same as the low-power detect threshold.
Software-Driven Mode
1
Selecting Low-Power Sensor
Click on the desired sensor to be selected as low-power and click Configure as low power.
Configure as low power is also visible if you right click on sensor.
After configuring the button as a low-power sensor, the button turns green.
2
Enable Software-Driven Mode
Navigate to QTouch > Parameters > Low Power and uncheck the Configure event system checkbox to enable the Software-Driven mode.
Multiple buttons or sliders or wheels can be configured as low-power in this mode.
3
Select Sensors
Select two buttons and a slider and click Configure as low power as them as a low-power sensors.
This indicates all the sensors now act as Low-Power Software-Driven sensors.
Switching back to Event-Driven Mode from Software-Driven Mode
1
Enable the Configure event system checkbox.
2
Select any one of the sensors in the Sensor Selection dialog drop-down box to configure as an Event-Driven Low-power sensor.
