LEGO MINDSTORMS - The Unofficial Guide to Robots - Jonathan B. Knudsen Part 8

Tham khảo tài liệu 'lego mindstorms - the unofficial guide to robots - jonathan b. knudsen part 8', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 130 Note that we ve specified the value in hexadecimal -1066 but the display always shows decimal -4198 . pbFORTH provides two words that show or hide individual display segments basically everything except the numbers LCD_SHOW segment -- LCD HIDE segment -- These words show or hide the given display segment. Valid values are shown in Table 6-7. The values that are flagged as a sequence can be repeatedly called to update the display automatically. For example the datalog indicator 3018 consists of four quarters of a circle. The first time you show 3018 you ll see one quarter. Show 3018 again and a second quarter lights up. Do this three more times and the third quarter lights up the fourth quarter lights up and then all the quarters go blank and the sequence begins again. Table 6-7. LCD Segment Numbers Segment Number Hex Sequence Description 3006 no Standing figure 3007 no Walking figure 3008 no Input 1 selected 3009 no Input 1 active 300A no Input 2 selected 300B no Input 2 active 300C no Input 3 selected 300D no Input 3 active 300E no Output A selected 300F no Output A backward 3010 no Output A forward 3011 no Output B selected 3012 no Output B backward 3013 no Output B forward 3014 no Output C selected 3015 no Output C backward 3016 no Output C forward 3018 yes 4 Datalog indicator segments 3019 yes 5 Data transfer segments ascending 301A yes 5 Data transfer segments descending 301B no Low battery indicator 301C no Short range download indicator table continued on next page 131 table continued from previous page Table 6-7. LCD Segment Numbers continued Segment Number hex Sequence Description 301D no Long range download indicator 3020 no All segment LCD_SHOW only Conveniently you can clear the entire display with a single word LCD-CLEAR -- This word clears the RCX s display so that no segments are lit. Input Control Words Before you configure inputs or read values from them you should initialize pbFORTH s input system with the following word SENSOR_INIT -- This .