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Control Power Functions from RCX2

Posted: 08 Jan 2011, 21:37
by nikzagvit
Hello everyone!
Has found on resource PHILIPPE HURBAIN section on control RC Nitro Flash with RCX2 http://www.philohome.com/nitroflash/rc_nitro_rcx.htm. I had a question, whether it is possible to control Power Functions with RCX2?
Has looked at the documentation to Power Functions protocol, the modulated signal 38 кГц is used, IR transmitter RCX2 as can transmit signals on this frequency. Means theoretically probably to control Power Functions with RCX2?

Thanks.

Re: Control Power Functions from RCX2

Posted: 08 Jan 2011, 22:05
by mattallen37
From what I understand, you want to control PF with a 2.0 RCX, right? I think in theory it is possible, but you would probably need to write your own FW to do so. The PF protocol is way different than the IR protocol used by the original RCX FW.

Also, the 2.0 RCX uses a 76khz receiver, not 38. Also, I HEARD that it uses 76 for the IR transmitter carrier, but I only heard that from one source, so I can't be sure. I am positive though, that the 1.0 RCX's use 38 for the receiver, and I am quite sure for the transmitter as well.

Re: Control Power Functions from RCX2

Posted: 08 Jan 2011, 22:48
by nikzagvit
The RCX2 can transmit serial data out the IR port, the transmit buffer can hold up to 16 data bytes. It means that rcx2 can transfer any 16 bytes data packets. As from NQC_Guide page 40.
Image
All the same quits that it is possible to write a management program without change FW?

Re: Control Power Functions from RCX2

Posted: 08 Jan 2011, 23:09
by mattallen37
Right, it sends serial bytes, and I am almost 100% sure it uses normal serial protocol. PF on the other hand, does NOT use anything nearly the same as standard serial protocol, IIRC. Unless you could feed in an array of 1's and 0's, with start bits and all that for it to transmit, I don't think you could do it with the standard firmware.

Re: Control Power Functions from RCX2

Posted: 13 Jan 2011, 08:22
by nikzagvit
Has studied the documentation on LEGO Power Functions RC.
FW RCX2 can clearly generate signals:
Low bit range 316 - 526 us (Approximately corresponds to FW RCX2, 2400 baud)
High bit range 526 – 947 us (Approximately corresponds to FW RCX2, 4800 baud)
For transmission of the mainframe of the data.
But proceeding from the documentation on NQC_Guide, standard FW RCX2 can't generate a signal (Start/stop bit range 947 – 1579 us).

From here and the question to knowing people, and whether supports the hardware RCX2 signal generation in 7200 baud?
Whether there is a possibility to rebuild FW RCX2, for operation with such value (7200 baud)?

Excuse for my English

thanks Nik