I think mine was even more DIY. A counter and DIP switches with LED's on the address side to select the address , DIP switches and LEDS on the data side to input the the 8 bit data and to check if the data was really programmed correctly.
All by hand , address per address.
I've seen the youtube vid , but I'm not going to buy one that I will barely use.
Your diagram is spot on what I had in mind but not exactly the same .
I would put 3 D-flipflop or latches after the eprom to clock in the 5 bit data for each PWM. I think the 3 extra bits would not even be necessary , the counter for the 2 first address bits could also select de FF or latch . (The 3 extra bits could even be used for dimming , but then the program gets more complex).
Although I like doing a project like this , it should be easier with a custom IC instead of the EPROM. Or maybe I should go the simpler way with much less colours like pcan says , but more than 8 !
All by hand , address per address.
I've seen the youtube vid , but I'm not going to buy one that I will barely use.
Your diagram is spot on what I had in mind but not exactly the same .
I would put 3 D-flipflop or latches after the eprom to clock in the 5 bit data for each PWM. I think the 3 extra bits would not even be necessary , the counter for the 2 first address bits could also select de FF or latch . (The 3 extra bits could even be used for dimming , but then the program gets more complex).
Although I like doing a project like this , it should be easier with a custom IC instead of the EPROM. Or maybe I should go the simpler way with much less colours like pcan says , but more than 8 !
This is a old style circuit so you may do old style analog tricks. Add a small capacitor between the resistor ladder and ground to smooth the transition. You will cycle through 8 colors only, but smoothly.
So, yes, you will use multiplexing.
If I understand, you have the solution, you only miss a way to program your EPROM.
You can prepare EPROM content in an Excel file, one byte per line and ask here or on EEVBlog if someone is willing to program it for you. Based on XL file it shouldn't be difficult to produce a file compatible with the target programmer.
DIYAudio his a great place, there are many people here happy to help.
Chris
Yes multiplexing between the 3 LED data buffers for the PWM.
Well I opened this thread because I realised that the eprom would be the problem and that maybe some one here had a good solution ( without a uP/controler or IC's that needs commands from devices on an I2C bus or other. So a real custom IC already programmed to do the whole red to blue sequence.
The problem is not just the act of programming , but I need to "compose" about 98k addresses with 8 bit data and that is too much work even in an excel document.
And no guaranty that what I put in the eprom is good enough and does what I envisioned.
I'm still looking around , but maybe in the end I'll try the analog/low tech version with 4022 / 4017 types but much more than 8 colours , and yes like pcan says with cap's to smoothly go from one colour to the next.
Well I opened this thread because I realised that the eprom would be the problem and that maybe some one here had a good solution ( without a uP/controler or IC's that needs commands from devices on an I2C bus or other. So a real custom IC already programmed to do the whole red to blue sequence.
The problem is not just the act of programming , but I need to "compose" about 98k addresses with 8 bit data and that is too much work even in an excel document.
And no guaranty that what I put in the eprom is good enough and does what I envisioned.
I'm still looking around , but maybe in the end I'll try the analog/low tech version with 4022 / 4017 types but much more than 8 colours , and yes like pcan says with cap's to smoothly go from one colour to the next.