Does anyone remember the old-school Lego Mindstorms bricks (RCX, Scout) that used infrared to communicate? Lego released an IR remote to control them with, but I can't seem to get my hands on one of those. I have a Lego Mindstorms Scout and I wish to control it via Infrared with the Arduino. If any of you happens to have the remote, can someone capture the remote codes for all of the buttons and send them to me either here or via PM?
old-school Lego Mindstorms bricks (RCX, Scout) that used infrared to communicate?
Yes it was simple. It just uses normal serial data sent to a IR LED. The signal is inverted so that the mark state there is no IR and for a space there is.
It uses 9600 baud, 8 bits, no parity, one stop, one start.
There is no RCX or Scout marking on mine - just LEGO.
I hooked it up a few years ago & my memory is that it is what Mike suggested. The real issue is to get the commands for control, as I believe the device just transmits the serial as modulated IR.
I am a bit busy for the next few weeks, but if you don't get anywhere, I can try to help - time permitting.
Out of curiosity, I just opened it up to see whats inside:
IR Receiver: TSOP1138 (so modulation is 38kHz)
IR LEDs: 2 (possibly connected to the switch for Low/High Power.
Power: 9V battery
All SMD components except the IR receiver & IR LEDs and one beefy resistor on the serial circuit.
Modulation is via 2 74xxxxx series chips as part of the oscillator circuit (no sign of a 555). The serial I/F is driven by transistors. Date codes are 1998 (PCB) and 1999 (ICs)
So it should be possible to follow Mikes tips and just build your own with an Arduino.
I suggest getting a more modern TSOPxxxx38 (TSOP34438) or maybe even the TSSP4038 as your IR receiver.
It should be possible to feed the IR receiver directly into a UART rx pin and for Tx - generate a 38kHz PWM while turning it on/off to match the timing of signal being sent. Of course the hard bit is to find the signals , which this just relays (from what I saw on the PCB)
