| ??? 08/25/05 20:27 Read: times |
#100103 - To reduce the data amount to transfer Responding to: ???'s previous message |
To reduce the data amount to transfer,
a) Make up the figure as poly-line. Each line has brightness factor. b) Send the graphic data as sequence of a pair of corner point coordinates and line brightness (X(n), Y(n), Br(n)).... Line brightness is represented as the moving speed of the laser spot. On the device, the position of the mirror is refreshed at constant interval. When the laser spot is on the line of (X(n),Y(n)) - (X(n+1),Y(n+1)), the coordinates (x,y) of the mirror is represented as follows. x = X(n) + Br(n+1) * dx * cnt / sqrt(dx*dx + dy*dy) y = Y(n) + Br(n+1) * dy * cnt / sqrt(dx*dx + dy*dy) where dx = X(n+1) - X(n), dy = Y(n+1) - Y(n) cnt: number of time intervals after laser spot is on this line. sqrt: square root This formula seems to be heavy for 8bit MCU at a glance, but several 10kHz interval will be achieved on fast one-clocker 51, under next condition. a) Limit coordinates to 8bit b) Use table method for the calculation of square root. c) Integer (fixed point) math Tsuneo |
| Topic | Author | Date |
| Laser projecter / 8051 timer/PWM | 01/01/70 00:00 | |
| Doubtful | 01/01/70 00:00 | |
| if speed is an issue | 01/01/70 00:00 | |
| DAC | 01/01/70 00:00 | |
| To reduce the data amount to transfer | 01/01/70 00:00 | |
| table | 01/01/70 00:00 | |
| No free lunch! | 01/01/70 00:00 | |
| understandable | 01/01/70 00:00 | |
| table and another approach... | 01/01/70 00:00 | |
| VC program finished | 01/01/70 00:00 | |
| Interrupt-driven Serial IO | 01/01/70 00:00 | |
| stuck in a rut as so amny before you, wh | 01/01/70 00:00 | |
| F120 overkill | 01/01/70 00:00 | |
that may be, but the proposed 12 clocker | 01/01/70 00:00 |