Hi!
I'm starting to build my own controller for Kerbal Space Program (KSP), and I would love to use five 10 segment led bargraphs to indicate the levels of my fuel, monopropellant, etc.
I've been doing some research and most point to daisy chaining multiple 74HC595 shift registers and control them that way.
However, I came across the MAX7219CNG which says that it can control up to 64 LEDs. Which would be perfect since I'd be controlling 50 of them.
What would be the up or downside of each?
I know nothing of KSP. Would the bargraphs all be localized to, for example, a space 15 cm x 15 cm? If so, absolutely use the 7219. The only reason I can think of to go with the shift register approach is if you wanted to spread the bargraphs out across several feet of a surface, where the line lengths become a problem for the 7219.
The shift register approach may be simpler to grasp, though, if you're new to programming.
The bargraphs would be next to each other yes. maybe a cm between them.
I'm not new to programming, so that shouldn't be an issue.
To use the 7219 you have to consider the driver as 8 groups of 8 rather than just a matrix. I had several comments in another thread about selecting individual LEDs for an analog clock stating at post 13. You would need to rework it to select multiple LEDs for a bar graph display.
@oldcurmudgeon is correct, there will be some minor gymnastics in wiring your LEDs into the 8x8 'concept space' of the 7219, but nothing difficult. You'd have similar 'gyrations' wiring them to 8-bit shift registers, anyway, because you'd have to come up with the extra two bits in each case, unless you arranged them as 5 strings of two 8-bit shift registers, and just not used the last six bits of the second shift register.
IIRC, the MAX7219 library I used a while back even had an 'array' mode that let the user work with the LEDs as a 1 x 64 array, so once you get it wired, you can stop thinking about it.
A Neopixel matrix can do that without a wiring cobweb.
Not cheap though.
Leo..
These pre-made 8x5050 sticks are nice for about US$20 for quantity 10. I did NOT name them.
Another option could be an HT16K33 module. This can drive an 8x16 led matrix, so your 5x10 might be less tricky than with MAX7219.
HT16K33 can also scan a keypad!
I would use an LM3914 chip. It is actually made to do this this job, as it converts a liner voltage into the appropriate segments to drive.
Also look at the LM3915 log 3dB per step. and LM3916, for VU (Volume Units) for using with sound projects.
How would you recommend @eaurouge86 makes the analog signals to drive those chips? Arduino PWM + low pass filters?
I like the idea of the neopixel but it doesnt quite fit with what I had in mind! Thanks though.
Hi! Ive no use for the audio module, but it does look like a good option!
Why are you not accepting the proposal of post #6?
You may try the following setup (Fig-1):
I did now; thanks!
Which one?
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