Today I've made some tests with my PIC16F628(A) Microcontroler and SX130IS to clarify Timing diagrams
for several options in CHDK USB Remote control V2. I prefer Ricoh CA-1 (Switch type) and my pulse train for
several buttons was consistent with that.
Although I had not so many buttons, I decided to check other options and were generated the necessary pulse sequences (with change in software).
All pulse width and Gaps between pulses are checked with Tektronix 2253 - 100 MHz dual Beam Osciloscope.
1.Button Half Press
--> Start pulse width 20 msec and till 35 msec are OK.If they are below 20 and over 35 msec Cam some time missed to react.If start pulse is = > 40 msec Cam not respond.
-->The GAP after first pulse was 1 sec, but can be and less to say 0.3-0.5 seconds it's enough Cam to
Focus e.t.c..If you prefer to see what happen with Focus, TV, AV e.t.c. make it 2-3 seconds.
-->Last 2 pulsess for Half Press Release are 30 msec, the between pulses Gap is also 30 msec.Approximately 1:1
2.Button Full Press
-->Start pulse is 100 msec width and no Problems, followed by 0.3 sec Gap and two Full Press Release pulses width 30 msec (GAP 30 msec)
It is very dificult to see the green reactangle for Focus (the things happened very quick), but
all is OK with Focus e.t.c.It is possible before Full Press pulse to add Half Press pulses in the chain.
3.Button Burst Go (Ricoh CA-1).
Why such button ? I could not make Burst to work unless in Ricoh CA-1 mode !
I tried all possible ways exept Ricoh CA-1 but only one shoot occurs, burst does not work !
If Ricoh CA-1 is checked all is OK.
--> One Start pulse 25-30 msec only.
To Stop you need two same pulses with Gap also 25-30 msec.With one pulse you can't stop the burst no matter how width it is.
4.Button Burst Stop (Ricoh CA-1)
--> Two pulses 25-30 msec only with 30 msec gap between to stop burst.
Half Press button due to two pulses on the end start burst and then immediately stop it..
Video Mode (Ricoh CA-1 )
-->Half Press start Record.Second Half press stop it.OK.
Quick (Ricoh CA-1)
--> Half Press also works.
Zoom Mode (Ricoh CA-1).
You need 5 buttons at least.
100-120 msec pulses width, with 30-40 msec GAP between pulses doing very good job.80 msec are not enough!
1.--> 1 pulse = 1 step Zoom in... to say from 28 to 30-31-32 (some time, very rarely occurs 2 steps) and
so on... till 336 for full Zoom In
2.--> 2 pulses = 1 step Zoom out
3.--> 3 pulses = SHOOT !
4.--> 4 pulses = Full Zoom In
5.--> 5 pulses = Full Zoom out
Here I see some difference in the number of pulses from CHDK wiki... Will be good if there is possibility to make 5 or 10 Zoom steps at once somehow and to avoid 1 step moving.
Bracketing can't work in Ricoh CA-1 mode, but if in Switch type OnePush is checked all is OK.
-->You need only One pulse - width 30 msec.Half Press Ricoh's CA-1 pulse sequence can't work.
Specifically works, but gets sometime 2 Shoots due to two pulses on the end of sequence
That's not very bad I belive...
No other test were made.The given Timing with 4 buttons is for SX130IS and Ricoh CA-1 Switch
type.Maybe it is the same for many P&S Cams.
Clearly, we need more buttons to better exploit the potential of CHDK USB Remote control V2.
Microcontrolers can do that, and PIC 16F628(A) in my case can accept up to 10 Buttons.