VK202-25 with Keypad - Garbage characters on screen
Posted: Mon Nov 11, 2002 9:08 am
I have a VK202-25 VFD and it shows garbage chars on the screen if more than one button is pressed on the keypad at the same time. Is there any workaround for this behavior?
Just for background, the reason that more than one button goes high is I have a jog wheel that has three wires: common, out1, out2. The common is attached to a column and the two outs are connected to different rows. When the jog wheel is spun (left or right), you can tell which direction it is rotating based on which out goes high first. The problem is the outs go high very close together, maybe even with a slight overlap where they are both high. I have tried toying with different debounce time settings, but to no avail. When I spin the jog, I get "dddddd" on my display and nothing is placed in the keypad buffer. All other keys are functioning properly. It would be acceptable (preferred even in this specific case) if the display did not get garbage characters and only the first key were sent when multiple were simultaneously pressed.
And for the curious...why do I have a jog wheel? I have gutted a Sony S530D DVD player and am building a home theater pc inside it. I have designed pcboards to replace the originals so that all buttons on the front panel are still operational. The VFD replaces the original display and the dvd player's builtin filter gives it that nice blue color! The final motherboard will probably be the new Eden2 mini-itx board once it is available. I am driving the display with custom software that is about 95% complete and will play all common media types. Pics will be posted for those who are interested once I get this final hardware problem resolved.
Thanks!
-BK
Just for background, the reason that more than one button goes high is I have a jog wheel that has three wires: common, out1, out2. The common is attached to a column and the two outs are connected to different rows. When the jog wheel is spun (left or right), you can tell which direction it is rotating based on which out goes high first. The problem is the outs go high very close together, maybe even with a slight overlap where they are both high. I have tried toying with different debounce time settings, but to no avail. When I spin the jog, I get "dddddd" on my display and nothing is placed in the keypad buffer. All other keys are functioning properly. It would be acceptable (preferred even in this specific case) if the display did not get garbage characters and only the first key were sent when multiple were simultaneously pressed.
And for the curious...why do I have a jog wheel? I have gutted a Sony S530D DVD player and am building a home theater pc inside it. I have designed pcboards to replace the originals so that all buttons on the front panel are still operational. The VFD replaces the original display and the dvd player's builtin filter gives it that nice blue color! The final motherboard will probably be the new Eden2 mini-itx board once it is available. I am driving the display with custom software that is about 95% complete and will play all common media types. Pics will be posted for those who are interested once I get this final hardware problem resolved.
Thanks!
-BK