Depends on how the joystick switching function is done, and if you can/want to rewire the joystick.leenew wrote:Yep me too
I will pull one apart and also check pinout diagrams for the beeb and see where I go from there.
Will I definitely need transistors? or can this not be done with simple wiring?
I seem to remember someone saying it had been over-complicated but can't remember where, or whether he offered the simple solution!
Lee.
Yes, you will need four resistors, all the same value.leenew wrote:Hi,
I am going to use the arcade joystick pictured above.
This uses 4 individual enclosed microswitches.
I will also use arcade buttons for fire buttons which have individual microswitches.
can i just wire this up? will the port just see full movement when a switch is pressed? or do i maybe need some resistors?
ta.
Lee.
Also note that the Beeb ADC only has 4096 values and so increments in steps of 16. I just did a quick test with the Acorn BBC analogue joysticks and ADVAL(1) - the only one I bothered to test - reported a min of 16 and a max of 65520, which would correspond to "1->4095" on the ADC. Of course the numbers are backwards; 16 was "far right", 65520 was "far left"paulv wrote: Being an analogue port, the channels range from @0 to 65535 and sit at around half way when the stick is centred. The figures are approximate and depend on the machine in question and how far out of whack the reference voltage is etc. For most Beebs I've seen none reach the maximum and minimum limits.
Code: Select all
VREF
pin 14 O------+------+-----------------+------+---- VREF
(red) | | | |
|¯| O Left |¯| O Up
R| | \ Switch R| | \ Switch
|_| O |_| O
| | | |
Ch0 | | | | Ch1
pin 15 O------+------+ +------+-------O pin 7
(green) | | | | (blue)
|¯| O Right |¯| O Down
R| | \ Switch R| | \ Switch
|_| O |_| O
| | | |
A-GND | | | |
pin 8 O------+------+-----------------+------+---- Ground
(black)
Note pin 15 is shown as channel 0 for port pin out, but BASIC uses ADVAL(1).
Note pin 7 is shown as channel 1 for port pin out, but BASIC uses ADVAL(2).
Fire switch 1 wired between pin 13 (white) and ground.
Fire switch 2 wired between pin 10 (yellow) and ground.
Colours quoted are the wire colours in my home made joystick cable.Mark1024MAK wrote:Yes, you will need four resistors, all the same value.
The actual value is not critical, but they must all be the same value (within say 5% to 10%, the normal resistor tolerance is 5%). A value of between 10k ohms and 22k ohms is good.
Use the diagram "Figure II" in the BBC Micro User article above as a guide.
The above is almost completely incorrect!sydney wrote:Looking at the photo's in Paul's post I've deduced the following:
All 4 ground pins on the microswitches are connected to each other and ground on the beeb connector(pin 8 ).
The remaining pins on the up and down switch are connected in series to each other and pin 7 on the beeb connector. The same for left and right to pin 15.
) a Voltmace 3a for "commodore", i tested with my c64 and didn't work well so... i found this thread and added the 5v line to the potentiometer, and a 22k resistor between 5v and variable line of both potentiometer (this because the 100k potentiometer seemed too high for beeb, and joystick gave always too high reading).
neat if a little wasteful.It's right Tricky, i rechecked the schematic and it's 0v (not 5v) line that i ported from buttons' pcb to potentiometers. And, i placed the resistors between 0v and variable pins. Sorry, but i didn't test voltage with multimeter, and probably inverted 7 & 8 pin when looking at db9 original connection.tricky wrote: ↑Thu Jan 31, 2019 7:22 am Sorry to keep going on!
On a beeb joystick, the fire button only connects to 0v so for a two button stick you only need: 1.8v, ch0, ch1, 0v, fb0 and fb1.
I don't know the joystick you are talking about, so it might want 5v for something else or I could just be completely wrong!
I'm pretty sure on my Atari to beeb adapters I only use the 5v for the analogue switch ic. On my megadrive to beeb ones, the 5v is needed for the switch and for the pad as they have internal ICs.
Sorry for rambling.
I would have thought that you mod would make the stick off centre.
