I am thinking of buying a Teensy-type board (specifically, the Teensy++ 2.0) to control five 8x8 LED matrices. These will be "bare" LED matrices, with resistors and wire connected in such a way as to allow 32 pins to control the whole thing.
I am thinking of following this procedure:
Choose any thirty-two pins available for digital output. Treat these as four sets of eight pins each. I will call these sets A, B, C, and D. I will call the LED matrices 1, 2, 3, 4, and 5.
A and B together control 1
A and C together control 2
A and D together control 3
B and C together control 4
B and D together control 5
(I could squeeze in a sixth matrix, but for my purposes, five is enough.)
Can I use the analog output pins on the Teensy++ 2.0 as digital pins? I know that if I use the digital pins in the middle of the board, I will then have enough outputs, but the analog output pins are easier for me to get at, especially for purposes of breadboarding.
Also, the reason I am doing DIY-style multiplexing is that I am not satisfied with some commercial multiplexed displays: the refresh rate is too slow. I intend to have a refresh rate of several kilohertz (yes, kilohertz), or even tens of kilohertz if I can manage it. Any suggestions?
The purpose of all this is to make a digital clock.
The display matrices will be arranged as 8 rows x 40 columns of LEDs.
There will be at least two buttons for controlling the clock. Do any of the chip's inputs contain pullup resistors so I can save myself some assembly time here?
As it's a clock, does the board contain a crystal or ceramic oscillator? I find that with ceramic oscillators, I get timekeeping accuracy more befitting a mechanical clock.
Lastly, will this thing work with the Arduino Wire library (for a Chronodot), and if so, which pins do I use?
Thank you for your patience.
I am thinking of following this procedure:
Choose any thirty-two pins available for digital output. Treat these as four sets of eight pins each. I will call these sets A, B, C, and D. I will call the LED matrices 1, 2, 3, 4, and 5.
A and B together control 1
A and C together control 2
A and D together control 3
B and C together control 4
B and D together control 5
(I could squeeze in a sixth matrix, but for my purposes, five is enough.)
Can I use the analog output pins on the Teensy++ 2.0 as digital pins? I know that if I use the digital pins in the middle of the board, I will then have enough outputs, but the analog output pins are easier for me to get at, especially for purposes of breadboarding.
Also, the reason I am doing DIY-style multiplexing is that I am not satisfied with some commercial multiplexed displays: the refresh rate is too slow. I intend to have a refresh rate of several kilohertz (yes, kilohertz), or even tens of kilohertz if I can manage it. Any suggestions?
The purpose of all this is to make a digital clock.
The display matrices will be arranged as 8 rows x 40 columns of LEDs.
There will be at least two buttons for controlling the clock. Do any of the chip's inputs contain pullup resistors so I can save myself some assembly time here?
As it's a clock, does the board contain a crystal or ceramic oscillator? I find that with ceramic oscillators, I get timekeeping accuracy more befitting a mechanical clock.
Lastly, will this thing work with the Arduino Wire library (for a Chronodot), and if so, which pins do I use?
Thank you for your patience.