DIY Roomba Virtual Wall, Part 4

So I went ahead and made another Roomba Virtual Wall. Everything else is pretty much the same as before, except I made each mounting layer one single ring, instead of 2 separate pieces. The single-piece design makes them easier to align and attach, at the expense of slightly longer print time and more filament used.

When soldering the proto-board, I tried moving the 3 resistors to the bottom of the board. Bad move. It was too crowded. In the end, I moved 2 of them back to the top.

I found that the IR LED that I used for this unit is actually the one I salvaged from the broken Roomba Virtual Wall because it has a very narrow degree of projection (2 ~ 3° at most). I thought the first unit had it.

What happened was, I was testing out the IR LED from the virtual wall and the old TV remote on the breadboard, and somehow got them mixed up. So I thought the first unit was using the IR LED from the broken virtual wall, but actually it had the TV remote IR LED, which makes sense now, because it has a much wider degree of projection (~30°).

For my own usage, it doesn't really matter, so I won't be making any changes. But if the IR beam needs to be as narrow as possible, then it pays to purchase an IR LED with that characteristic.

Part 1 - Part 2 - Part 3

Comments

Update: Line adapter for Ozito Blade Trimmer

Update (Dec 2021): If you access to a 3D printer, I would now recommend this solution , which makes it super easy to replace the trimmer line. I have been using it for a few months now with zero issue.

3D Printer Filament Joiner

I have been looking at various ways of joining 3D printing filaments. One method involves running one end of a filament through a short PTFE tubing, melting it with a lighter or candle, retracting it back into the tubing and immediately plunging the filament to be fused into the tubing: One problem with this method is that you can't really control the temperature at which you melt the filament, so you frequently end up with a brittle joint that breaks upon the slightest bend. Aliexpress even sells a contraption that works along the same line. As it uses a lighter or candle as well, it suffers from the same weakness. I am not even sure why you need a special contraption when a short PTFE tubing will work just as well. Another method involves using shrink tubing/aluminium foil, and a heat gun: But a heat gun is rather expensive, so I wanted to explore other alternatives. The candle + PTFE tubing method actually works quite well when you happen to melt it at the rig

Attiny85 timer programming using Timer1

This Arduino sketch uses Timer1 to drive the LED blinker: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 /* * Program ATTiny85 to blink LED connected to PB1 at 1s interval. * Assumes ATTiny85 is running at 1MHz internal clock speed. */ #include <avr/io.h> #include <avr/wdt.h> #include <avr/sleep.h> #include <avr/interrupt.h> bool timer1 = false , led = true ; // Interrupt service routine for timer1 ISR(TIMER1_COMPA_vect) { timer1 = true ; } void setup() { // Setup output pins pinMode( 1 , OUTPUT); digitalWrite( 1 , led); set_sleep_mode(SLEEP_MODE_IDLE); // Setup timer1 to interrupt every second TCCR1 = 0 ; // Stop timer TCNT1 = 0 ; // Zero timer GTCCR = _BV(PSR1); // Reset prescaler OCR1A = 243 ; // T = prescaler / 1MHz = 0.004096s; OCR1A = (1s/T) - 1 = 243 OCR1C = 243 ; // Set to same value to reset timer1 to

Random Sequence

Search This Blog