hi everybody, I'm looking for the simplest way to add a proximity detector that detects when something moves in front of it, at a range of ~ 1meter - no info on distance is necessary, just on/off. Can you point me to some resource - possibly DIY? I only found until now the Sharp GP2D12, but I'd prefer a slightly larger range. thanks!
You will find the LM565 ? PLL to be the lowest cost and highest performance device . Its antenna pattern is distorted by objects and the rate is readable .
Since its a PhaseLockedLoop , it will read rate as well as the pull . You can gaurd them , so they will be able to figure if the object is moving and how fast and what direction . There is less cost and hassle , using LM565 . But of course you must use an ARM 7 , 144 pin , to make it "sing"
I'm using them and a $20 700by420 pixel BW CCD camera to control moving objects like robots and cars . It has .01 LUX ( I.R.) Im using front surface mirrors that rotate in front of the camera , periodically to expand the vu of the camera . I will scan only every 10th vertical line and evaluate it , as a insects compound eye does . Then switch to full scan to do slow stuff . BTW I2C and RS232 and SPI . Everyone thinks they are narrow . But clever people can make them work more . You might try using SPI to do RS232 and vice versa , and SPI sub for I2C etc etc ..
We read the specs , and get blinded , because spec sheets are poorly written leave out stuff and amount to advertizing ! So we arent brave enuf to experiment . I will be booting ARM by many methods . I want flexibilty and fault tolerance , so when i want to boot it , i want to be able to select many methods of booting , at boot time . The SPI bus is the lowest cost and smartest method , just put a tiny 2K EEPROM there . If you boot wide , then you'll have to configure EXT RAM . SPI is easier . 74HC595 and 597 is a generic way to do parallel on SPI bus . HC299 also works . I will use many ARM 7 mcu's to do the work .
thank you for the GP2Y0A02YK. suggestion, I didnt know it and I guess it will be OK. Concerning the LM565, I confess I did not understand how to use it. If you (werty) have a link to some schematics I'll be happy to study it...
ignore werty. in fact, ignore anyone whose name is a linear sequence of characters on a standard keyboard. it is unlikely that you would want to use a phase locked loop for this application.
sharp rangefinders work pretty well. i have used them on every robot i've built.
if you want to d.i.y, you could use an infrared led and detector as available at radio shack. that, however, would be a luminance based sensor, so a good reflector at much more than one meter range would trigger it before a poor reflector at less than one meter. also, it would have as wide beam pattern as the led, which is usually pretty wide.
sharp rangefinders have an infrared led with a focus lens so they have a pretty narrow beam width. also, they measure angle, not luminance, so as long as there is minimum reflection they are unaffected by target color.
BTW I have been studying the ARM Instruction set . Its a closely gaurded secret . Everyone wants you to see only nuemonics and not the binary it refers to .
Ville Pietikainen of Finland , gave out a free xxxx.PDF on Thumb , but it was buggy . He does not understand the "H" bit . I've been searching for months , for second sources on Thumb ISA .
Fortunetly , Edward Nevill email@example.com has a more accurate chart .
Its a struggle , cause they want to appear a WIZARD , and show you how great their assemblers are . Assemblers are WORSE ! They lock 2 doors ! They claim Psuedo ops . But its supposed to be in a "macro" NOT a psuedo op !
Im doin ARM 7 and 9 . I have boxes full of ARM mcu's .
Every door closed ! ATMEL created some helpful tools to boot its AT91xxx . Bloat crap , SAMBA is 20MB ! I will instead program a tiny 35KB Editor "Qedit" to do the flashing .
All the I.D.E.'s and C/C++ compilers are a huge waste of effort , in programming MCU's for robots .
You can create s/w in minutes , with a modern "loader" in 8 KB of the Flash RAM .
But exect the same Luddite Loaders from all the big companys , ST , ATMEL, Philips , all waste the 8KB , it will only look in 2 places ! UART and USB , and then , expect deaf and dumb .
My loader starts in SRAM , so it can be fixed , if it dont work , in minutes . after weeks of coding , when you have not needed to "improve" it , then flash it ..... Always treat your flash as a HDD , and use precious SRAM for hi-speed code .
The performanceof ARM 7 is slowed by less SRAM . I found 2 ARM7s with 64KB and 96KB SRAM . Your code running inside , will run very fast and at extreme low power !
Im doin many things , ARM EVBs , Nintendo DS Lites , GP2X boxes , all ARM mcu's . Very powerful !