Another PCB mod and Schematic

[Nightwing]

Cool Grab!

For the ZZ group the receiver side of the circuit is different. But odds are the IC on is the same.

Again good grab.

[Nightwing]

What I have piced together for the front in.

[Nightwing]

And now for the secmatic.

[DensityMan]

Would be REALLY nice to have learned Japanese, Chinese and Electronicese before these things came out... Hehe

Any English-language translations for the various mod-sites out there?

(desperately trying to absorb all of the engineer-speak in here and LOVING the pics on the Japanese sites... just feel like I'm missing steps due to language barriers... *grumble*)

[Nightwing]

There is Babble fish at Altavista.com search site. For the Greek of electronic it wont handle it. Uses it for both French and Japanes but its pritty bad on some things.

PS: I think there is a ground missing on the left side of the circuit diagram.

[funkymonkey]

Ok, reading this thread it seems like DayFall and Nightwing know an awful lot about what they're talking about. I wont pretend to know most of what they're on about.

I may be asking for too much, but would it be possible for one of you guys to do a 'basic theory of operation' of the receiver PCBs?

It seems collectively, and through experience their is an awful lot of knowledge about Bit Char's out there, but i'd say the most complex and mysterious bit remaining is the PCB.

Any electronics gurus fancy doing a tutorial on the PCB board?

I only know basic electronics but would love to learn more about the board.

PS - Craig, where on earth did you get that detailed schematic from? Kudos to you!

[Dayfall]

I don't have any experience in the receiver portion of the electronics. Sorry. From looking at the RF from the transmitter, I can only guess that a number of pulses is sent; the resistors and capacitor on the PCB, that connect only to the IC, are what is used for the timing to count the pulses. I am guessing that the pulses duration determines the data. Either that or the pulses are simular to serial data, where each pulse is for each button on the controller.

Also I just had the experience of controlling a robot toy someone had with my ZZ controller. Combined from other stories I have heard, there seems to be quite a standard as to how the data is sent.

Could some one confirm if it is the same or diffrent than what is used for R/C cars and planes. I am betting that it is the same, and that teach pulse lasts 1ms-2ms depending on what data is sent!

[Snoopy]

The Bit remote uses a different protocol than "real" RC cars and planes.
Models with an analogue control use the 1-2 ms timing you mentioned, where the duration of the pulse determines the position of the servo (1ms= 0% 2ms=100%)
description here

The Bit remote uses another protocol that is very common for simple RC-toys, which allows only on or off and no intermediate values.
like this one

I looked inside the transmitter of a Fit-Racer (OEM-clone) but unfortunately I can not find any documentation for the transmitter IC (PT 8A977BP Y0238JW)
But it seems that many toys use the same protocol. Of course the channels may be switched so that left becomes forward

My remote has a 5th channel that is not used. My guess is that the "Bit Char-G Booster Machine set" uses the 5th channel for the turbo feature.

If someone has a Bit with the booster function he can try to connect pin 7 of the IC to ground, maybe this is the booster. If this works there would be no need to buy a new remote, just add a switch to your existing one.

[Dayfall]

Thanks! I suspected that may be the case. Now to find out if my ZZ has an extra channel.

[n2o_matt]

If you are using a duel batt mod then I don't think you should try shorting the resistors unless you really know what you are doing.

I was wondering if this multi cell mod would work. I think it might since the extra cells r on a seperate circuit. Their circuit is closed when power is sent to the transistor* using the origonal signal from the pbc. After the power is sent through the motor and then through a transistor* before going back to the pcb, so the pbc shpuldn't be able to tell a differance. I think this will prevent the pcb from frying.

*I don’t really know that much about electronics so I’m not sure if this will work. I was wondering if u could help me with a few questions? First, what exactly does a transistor really do? And does a resistor drop voltage, current or both? What do these mofets do, i haven't herd of them? And last, after energy goes through the motor y would it have to be droped by the resistor?

Hope this helps.

I have so far:
zz tubo motor (i think its faster than the nos)
this pbc mod
no reverse mod

Whats next?

[Nathan]

Iv'e had 2-cells for months. Works fine, cause resistors rduce current, so more voltage won't hurt anything. I cannot see how 2.4v would anyway

[Labmonkey]

just wondering if Dayfall
found an extra channel on the ZZ board. Great stuff in this thread...getting ready to do some mods to my first ZZ...just can't decide what to try first....too many good ideas here.

[Labmonkey]

Tried your mod.....I shorted r16, r19, r20, and r21, and I lost a lot of speed. Anyone else have this problem? would really like to find a boost without an extra battery...

Yellow Mustang Cobra
Mazda RX8