I have this speed display with the model number GDA-402GF,
I haven't been able to find any manuals on setting it up. I'm trying to set it up to be 33 on low and 66 on turbo, but haven't been able to get anywhere by brute force. Anyone have any ideas?
Applying 5V and ground to two of the pins at the bottom should get it to light up.
Don't think you could hurt it that way, but don't take my word for it.
But are you sure it's a "MHz" display?
For, usually, those have a shitload of jumpers. One for each segment and with four different settings to either light up with turbo on, turbo off, not at all or always.
Hard to implement with only eight DIP switches?
Maybe if it's been preconfigured for a couple of settings.
http://minuszerodegrees.net/led_speed_display … eed_display.htm
I like jumpers.
I'm not entirely sure to be honest. Even just HI and LO would be enough
http://minuszerodegrees.net/led_speed_display … eed_display.htm has nothing similar sadly.
The model # may just be the display part # rather than the whole thing - https://www.para.com.tw/en/product/402/ - there are older versions of the PDF on archive.org
The model number, it seems is not the entire assembly, but only the actual display. Searching for that would probably not give you anything in terms of jumper settings, I'm afraid
Please use the "quote" option if asking questions to what I write - it will really up the chances of me noticing 😀
Darn
8 switches means just 256 total possibilities. You say you tried to brute-force it, but not getting anywhere. What approach did you use? Systematically going through all 256 should give you all possible results. If what you want isn't in there, it probably can't show that - but then the question is what it can do...
Turn all switches off, apply power, then flip either one of the end switches to on. You should get a "1" on the display with one of those. Usually displays like that set the digits with BCD. Similar ones I've seen use jumpers though, instead of the DIP switches. But, I don't see a chip on there, although it could be a small surface mount one under the display. If it does have one, you usually need to hold down a button to program it for the high/low frequency.
dionb wrote on 2022-04-15, 18:05:8 switches means just 256 total possibilities. You say you tried to brute-force it, but not getting anywhere. What approach did you use? Systematically going through all 256 should give you all possible results. If what you want isn't in there, it probably can't show that - but then the question is what it can do...
the problem is each switch turns on some really awkward and nonsensical combination of lights.. And is affected by any other subsequent switch
I have something similar to this, with 2 banks of DIP switches. It sounds like yours works the same as mine. Each switch lights up one or more segments which together build up a number - so you have to work out which segments lit up together make a 3 or 6, or whatever number you need. Was trying to find pics of my one to demonstrate but it helps to grab a pen and paper to work out the combos.
Just guessing here (insomnia bout):
7 segments per digit, so one out of 8 switches to change the digit?
A jumper might "fix" the setting for the chosen digit so you can move to the next digit.
