[TouchCore1.0] Algorithm & PCB Design Guide. V1.1 March 2008

Transcription

1 TouchCore Family #031 (AN031-V1.1) [TouchCore1.0] Algorithm & PCB Design Guide V1.1 March 2008 CORERIVER Semiconductor reserves the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time. CORERIVER shall give customers at least a three month advance notice of intended discontinuation of a product or a service through its homepage. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. The CORERIVER products listed in this document are intended for usage in general electronics applications. These CORERIVER products are neither intended nor warranted for usage in equipment that requires extraordinarily high quality and/or reliability or a malfunction or failure of which may cause loss of human life or bodily injury.. ( tech@coreriver.com)

2 Contents [PART I : Demo Board] [PART III : Algorithm] Schematic Diagram (One Channel Type) PCB Artwork Design PCB Artwork Design Guide Demo Board Design Samples (Slide Type & Matrix Type) [PART II : TouchCore Tool] TC Tool of TouchCore1.0 Initial Operation Run of TouchCore1.0 Enabling Touch Sensor Channel Making TouchCore1.0 Header File Features for Applied Algorithms Demo Application Flow Chart Terminology Part 1. Setup Initial State Part 2. Noise Cancellation Part 3. Environmental Change Trace Demo Board with Algorithms Other Algorithm for Slide Bar [2]

3 TouchCore Family PART I : Demo Board Schematic Diagram (One Channel Type) PCB Artwork Design PCB Artwork Design Guide Demo Board CORERIVER Semiconductor reserves the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time. Design Samples (Slide Type & Matrix Type) CORERIVER shall give customers at least a three month advance notice of intended discontinuation of a product or a service through its homepage. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. The CORERIVER products listed in this document are intended for usage in general electronics applications. These CORERIVER products are neither intended nor warranted for usage in equipment that requires extraordinarily high quality and/or reliability or a malfunction or failure of which may cause loss of human life or bodily injury.. ( tech@coreriver.com)

4 1.1. Schematic Diagram In more detail information about the pin description, please refer to manual of TouchCore1.0. The Gap (or Clearance) between Touch PAD & GND is approximately 2.0mm. [Touch PAD Part] J2 9mm X 9mm J3 9mm X 9mm TS0 TS1 TS[7:0] [PCB Material] Rigid PCB (FR-4) 2-layer PCB 1.6mm Thickness LED[7:5] [MCU Part] LED6 LED7 +3.3V TS0 +3.3V TS[3:0] C8 0.1uF R1 1k + D1 LED +3.3V + + [LED Part] J4 9mm X 9mm TS P1.1 P1.0 VSS VDD TS0 LED0 LED1 LED2 LED3 LED4 LED5 LED6 LED7 J5 9mm X 9mm J8 7mm X 7mm TS3 TS4 TS[7:4] LED5 TS7 TS6 TS5 TS4 1 P1.2 / RSTB 2 TS7 3 4 TS6 TS5 U2 TC10-QF20IP 5 TS4 TS1 15 TS2 14 TS3 13 SDA0 12 SCL0 11 TS1 TS2 TS3 SDA0 SCL0 LED[7:0] J12 7mm X 7mm J13 7mm X 7mm TS5 TS6 [ISP Interface] +3.3V P2.4 P2.5 6 P2.6 P0.7 P LED4 LED3 LED2 LED1 LED0 +3.3V [Power Part] U1 KIA1117S33 GND OUT IN +9V (External Power) J14 7mm X 7mm TS7 SCL0 LED5 (RSTB) SDA0 LED[4:0] C11 10uF/16V TAN-B C12 10uF/16V [4]

5 1.2. PCB Artwork Design [Bottom Side : Circuit Part] [Top Side : Touch PAD Part] 2.0 mm (Gap) Touch PAD GND (Hatch) Hole (for LED) ISP Interface Board Name : TouchCore-DEMO V1.0m ( ) [5]

6 1.3. PCB Artwork Design Guide [Top View] The Contents for Design Guide is based on Only Demo Board. TouchCore-DEMO V1.0m Trace Touch PAD GND PAD Size 9mm X 9mm (TS[3:0]), 7mm X 7mm (TS[7:4]) PAD Gap (for GND) PAD Gap : 2.0mm Trace Width : 0.2mm PAD Size PCB Material Rigid PCB (FR-4), 2-layer PCB, 1.6mm Thickness GND Copper Plane for Touch PAD Hatch Plane, 60% Fill, Diagonal [Side View] Trace Routing We recommend the following method for trace routing, because of the parasitic capacitors. Touch PAD GND [Trace Routing] : Parasitic Cap. PCB (FR-4) Trace VIA hole The Position of Via Hole can be at any Touch PAD. [Good] [Not Good] [6]

7 1.4. Demo Board [Assembled Demo Board] [Top Side] Acryl Plate (1.5mm Thick.) 2-layer PCB (FR-4, 1.6mm Thick.) Touch PAD LED Hole ISP Interface (Bottom Side) OFF ON +9V GND Power Switch [7]

8 1.5. Design Sample : 1) Slide Type [Schematic Design] [PCB A/W Design] The Touch Sensor has generally three design types. (One Channel Type, Slide Type, Matrix Type) This Schematic Design is the sample for Slide Type Touch Sensor. GND TS0 TS1 TS0 TS[7:0] TS1 TS2 TS2 [Typical PCB A/W Design Guide] TS3 1 (or 2; Gap for GND) TS4 TS5 1 (Gap) 8 TS6 TS Unit : mm [8]

9 1.5. Design Sample : 2) Matrix Type [Schematic Design] [PCB A/W Design] This Schematic Design is the sample for Matrix Type Touch Sensor. The Shape of Touch Sensor is not fixed. The Total Touch Switch Channel is 15. (3 X 5 Matrix) TS0 TS[7:0] TS1 TS2 [Matrix Configuration] TS3 TS3 TS4 TS5 TS2 TS1 TS6 TS7 TS0 TS7 TS6 TS5 TS4 [9]

10 TouchCore Family PART II : TouchCore Tool TC Tool of TouchCore1.0 Initial Operation Run of TouchCore1.0 Enabling Touch Sensor Channel CORERIVER Semiconductor reserves the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time. Making TouchCore1.0 Header File CORERIVER shall give customers at least a three month advance notice of intended discontinuation of a product or a service through its homepage. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. The CORERIVER products listed in this document are intended for usage in general electronics applications. These CORERIVER products are neither intended nor warranted for usage in equipment that requires extraordinarily high quality and/or reliability or a malfunction or failure of which may cause loss of human life or bodily injury.. ( tech@coreriver.com)

11 2.1. TC Tool of TouchCore1.0 This GenICE2000 Manager is the GUI program for CORERIVER s MCU. To select the TouchCore1.0 MCU, select the TouchCore1.0 from device menu as below. To use the TouchCore1.0 tool (TC Tool), click the TC Tool button. The window TC Tool supports the touch sensor counter values of the enabled touch sensor channels. Counter values means Base, Threshold, & Current Values. [11]

12 2.2. Initial Operation [Before Initial Run] The base & threshold values can be generated with initial operation. First, click the button Initial. The base & threshold values are updated automatically. Base [Max] values are updated when you touch each PAD with your finger. Next, click the button Stop Initial for finishing the initial operation. Scanning & Updated [After Initial Run] [12]

13 2.3. Run of TouchCore1.0 [Before Run of TouchCore1.0] The current counter values of touch sensor channels can be shown at this windows TC Tool. First, click the button Run. The window TC Tool shows the current counter values as below. If user wants to stop of TouchCore, click the button Stop. Show Current Values [After Run of TouchCore1.0] [13]

14 2.4. Enabling Touch Sensor Channel [Touch Sensor Channel Enable Checking] The touch sensor channels can be enabled or disabled. The channel check boxes of the item Enable can be checked or unchecked by clicking with mouse. Fox example, touch sensor channel 3 & 5 are disabled (unchecked) and the other channels are enabled (checked) at left figure. [Run of TouchCore1.0] [14]

15 2.5. Making TouchCore1.0 Header File Make header file for TouchCore1.0 Click the button Write header Make header file name TC10_V3.2.h [15]

16 PART III : Algorithm Features for Applied Algorithms Demo Application Flow Chart Terminology Part 1. Setup Initial State (Initial Baseline Trace) Part 2. Noise Cancellation (Low Pass Filter) Part 3. Environmental Change Trace (Main Baseline Trace, Pattern Trace, Analysis of the Variance, Grass Level Filter) Demo Board with Algorithms Other Algorithm for Slide Bar (Weighted Averaging) [16]

17 3.1. Features for Applied Algorithms Kinds of Noise Slow Changing Noise Noise caused by environmental changes including temperature & voltage Abruptly Changing Noise Strong burst noise caused by external changes Noise caused by environmental changes due to initial operation Common Algorithms in CORERIVER s Solution Part 1. Setup Initial State Initial Baseline Trace Part 2. Noise Cancellation Low Pass Filter Part 3. Environmental Change Trace Main Baseline Trace Pattern Trace Analysis of Variance Grass Level Filter Application-Specific Algorithms Slide Bar (Weighted Averaging) [17]

18 3.2. Demo Application Flow Chart Initialize No Baseline Searching Baseline Adjust? Yes Read Sensor Baseline : 32 * 8 averaging Max. delta - bound < Baseline < Max. delta + bound 32 averaging Calculate Variance Specified 1 channel Calculate percentage & on # Yes Find Touch Down ID Variance? No No Touched? Yes Yes Repeated Read Sensor Same Touch ID Yes Touched? No Calculate percentage & on # No Touch Up Touch Up Yes No Same Touch ID No Repeated done? Yes Touch Down Track Baseline Baseline Adjust Snap Mode [18]

19 3.3. Terminology Baseline Minimum Not Touched Counter Value. This value is needed to be calculated the current counter value which touched or not touched. Threshold Touch Reference Value. If the current counter value is greater than the threshold, it means that TS channel is touched. Touchline Maximum Touched Counter Value [Touch Sensor Counter Graph] 255 Current TS Channel Counter Value Touchline (Touched) Counter Value Not Touched Touched Threshold (for Detect the TS Channel) Baseline (Not Touched) 0 Time [19]

20 3.4. Part 1. Setup Initial State (1 of 1) [Algorithm 1. Initial Baseline Trace] Algorithm for Slow Change Noise by Environmental Changes (Temperature & Voltage) Performance 0.5 Difference / Process (@Demo Board) Cycle & Memory Requirement (for 8 Touch Sensor Channels) Instruction# : 2,887 Cycles Process Time# : 0.96ms (@12MHz) Memory : Data = 24 Bytes (Including Local & Global Variables) Code = 200 Bytes Experimental Result Temperature Range : -20 ~70. [Counter Value Change with Temperature] Normal Temp. High Temp Low Temp. Counter Value Touchline Threshold Baseline Time [20]

21 3.5. Part 2. Noise Cancellation (1 of 1) [Algorithm 2. Low Pass Filter] Algorithm for Abruptly Change Noise by External Noise (High Frequency Noise) Counter Value Current Counter Value including External Noise (High Freq.) After LPF Counter Value Current Counter Value after Noise Cancellation Time Time Performance 32-tab Average Filter Board) Cycle & Memory Requirement (for 8 Touch Sensor Channels) Instruction# : 4,893 Cycles Process Time# : 1.6ms (@12MHz) memory : Data = 41 Bytes (Including Local & Global Variables) Code = 181 Bytes Magnitude Signal Pass LPF Curve Signal (Desired Counter Value) External Noise (High Frequency Noise) Noise Cancellation Frequency [21]

22 3.6. Part 3. Environmental Change Trace (1 of 4) [Algorithm 3. Main Baseline Trace] Algorithm for Slow Change Noise by Environmental Changes (Temperature & Voltage) Performance 0.5 Difference / Process (@Demo Board) Cycle & Memory Requirement (for 8 Touch Sensor Channels) Instruction# : 573 Cycles Process Time# : 0.19ms (@12MHz) Memory : Data = 26 Bytes (Including Local & Global Variables) Code = 213 Bytes Experimental Result Temperature Range : -20 ~70. [Counter Value Change with Temperature] Normal Temp. High Temp Low Temp. Counter Value Touchline Threshold Baseline Time [22]

23 3.6. Part 3. Environmental Change Trace (2 of 4) [Algorithm 4. Pattern Trace] This algorithm monitors the change status for all used Touch Sensor Channels, and analyzes the Pattern of the value changes. Counter Value CH0 Touchline (of Each Channels) Threshold (of Each Channels) Baseline (of Each Channels) CH1 CH2 CH3 CH4 CH5 CH6 CH7 Touch Sensor Channel If all the counter values are incremented together, and are smaller than each channel s threshold, the algorithm determines the counter value is changed by the environmental change. Performance Cycle & Memory Requirement (for 8 Touch Sensor Channels) Instruction# : 442 Cycles Process Time# : 0.14ms (@12MHz) Memory : Data = 38 Bytes (Including Local & Global Variables) Counter Value Case 1. External Noise Case 2. Touched CH0 CH1 CH2 CH3 CH4 CH5 CH6 CH7 Touch Sensor Channel If only some counter values are incremented, the algorithms determines the counter value is changed by the external noise or Touched. Performance Cycle & Memory Requirement (for 8 Touch Sensor Channels) Instruction# : 2,146 Cycles Process Time# : 0.71ms (@12MHz) Memory : Data = 47 Bytes (Including Local & Global Variables) Code = Total 98 Bytes [23]

24 3.6. Part 3. Environmental Change Trace (3 of 4) [Algorithm 5. Analysis of the Variance] Algorithm for the Strong External Noise by Environmental Changes. This algorithm checks the existence of Strong External Noise. If the existence of Strong External Noise, the algorithm Main Baseline Trace doesn t work. Weak Noise Strong Noise Counter Value Counter Value of CH0 Average Value of CH0 (Touched / Not Touched) by Var. Variance Weak Noise Strong Noise T1 time T2 T1 time T2 Performance Cycle & Memory Requirement (for 8 Touch Sensor Channels) Instruction# : 451 Cycles Process Time# : 0.15ms (@12MHz) Memory : Data = 15 Bytes (Including Local & Global Variables) Code = 100 Bytes [24]

25 3.6. Part 3. Environmental Change Trace (4 of 4) [Algorithm 6. Grass Level Filter] Algorithm for the effectively AWGN (Additive White Gaussian Noise) reduction at normal environmental condition. If the counter value is smaller than Grass Level, the counter value will be at baseline. (Refer to the counter values of CH1, CH3, CH6, & CH7 as below) Touchline (of Each Channels) Counter Value Threshold (of Each Channels) Baseline (of Each Channels) Grass Level After GLF Counter Value Counter Value = Base Value CH0 CH1 CH2 CH3 CH4 CH5 CH6 CH7 Touch Sensor Channel CH0 CH1 CH2 CH3 CH4 CH5 CH6 CH7 Touch Sensor Channel Performance Cycle & Memory Requirement (for 8 Touch Sensor Channels) Instruction# : 24 Cycles Process Time# : 0.06ms (@12MHz) Memory : Data = 1 Bytes (Including Local & Global Variables) Code = 3 Bytes [25]

26 3.7. Demo Board with Algorithms This Demo Board uses all the algorithms in this document. [Touch PADs] The 8 Touch Sensor Channel are used. (8-key Touch Sensor Application) V DD = 3.3V, F SYS = 12MHz, F SAMP = 24MHz. [Demo Board] Performance Cycle & Memory Requirement (for 8 Touch Sensor Channels) Instruction# : 6,711 Cycles Process Time# : 2.2ms (@12MHz) Memory : Data = 87 Bytes (Including Local & Global Variables) Code = 1,775 Bytes [26]

27 3.8. Other Algorithm for Slide Bar [Algorithm 7. Weighted Averaging] This algorithms supports the high resolution of touch sensing for slide bar application SLIDE i= n [( i) ( TS [( TS [ i 1] TS delta delta i= 1 Value = i= n i= 1 delta [ i 1] TS delta min)] min)] gain [Case 1.] [Case 2.] [Case 3.] [Case 4.] CH1 CH2 CH3 CH4 CH1 CH2 CH3 CH4 CH1 CH2 CH3 CH4 CH1 CH2 CH3 CH4 Counter Value CH0 CH1 CH2 CH3 CH0 CH1 CH2 CH3 CH0 CH1 CH2 CH3 CH0 CH1 CH2 CH = = = = Performance Cycle & Memory Requirement (for 4 Touch Sensor Channels) Instruction# : 1,376 Cycles Process Time# : 0.45ms (@12MHz) Memory : Data = 21 Bytes (Including Local & Global Variables) Code = 128 Bytes [27]