0
\$\begingroup\$

I've already built a few test prototype for a large(ish) 16-segment display board. I want to use a Arduino of ESP8266 to run it, with external power, and ICs for the Characters.

So far, I've been able to make 2 rows, with 8 characters each using a MAX6954 IC chip for each row. I've found 8 characters isn't enough, so I want 12-14. I could just double up and do 16 characters per row, with 2 MAX6954 per row. I want a total of 10 rows. The problem is MAX6954 for me cost almost 30 dollars each. Making the project $600 in IC chips alone, the rest of the parts are <100 dollars.

I've looked into doing a TLC5940 16-channel LED driver per character (about a 1.50 each). However it looks like you can only chain 40 together The following equation calculates the minimum frequency required: f(GSCLK) = 4096 ´ f(update). I don't know if it would be possible to drive 4 sets of 40 with an arduino, or would I need to chain Arduino?

The AS1130 chip says it can run 132 LEDs (wow) for under 10 dollars. But there is very little documentation for it. I've only been able to find a single library, that is optimized for dotmatrix displays, so I'm not sure if it would work in this use case.

any suggestions appreciated!

\$\endgroup\$
3
  • \$\begingroup\$ 10 rows times 12-14 characters times 16 segments is 1920-2240 segments. That's a lot. And it may also require substantial power supply design considerations, too. If the ICs (boutique, plus they come and go) are costing the hogs' share of your budget, switch to discrete components and modularize your system with separate MCUs per display section (make your own driver.) But since you are using libraries, this may imply you have limited programming skills. Regardless, you will need to provide many more specifications before anyone can really help provide a more detailed consideration. \$\endgroup\$ – jonk Aug 18 '18 at 23:24
  • \$\begingroup\$ @jonk thanks for the insight. I think my best bet is a brain mcu and then I can do 2 rows per mcu. Still a lot cheaper than the max solution. Thanks \$\endgroup\$ – Danielle Aug 18 '18 at 23:30
  • \$\begingroup\$ Any solution that works for you, I suppose, is the right one. I worked on modules with 768 LED segments (256 RGB LEDs) and used 6 ICs for each module. But those were commercial units and the ICs were custom. For discrete, I recommend getting a copy of Hewlett Packard's "Optoelectronics Fiber-Optics Applications Manual," 2nd edition. (It may be difficult/expensive, because I bought every copy I could find when Siemens-OSRAM told me to get a copy when working on the project. I filled a shelf with them, to give away.) \$\endgroup\$ – jonk Aug 18 '18 at 23:39

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.