[chbot] Displays

[Volker Kuhlmann]

MAX7219 dot matrix module
http://www.aliexpress.com/item/Free-shipping-Dot-matrix-display-module-MAX7219-single-chip-control-module-DIY-kit-for-arduino/32580544054.html
Chip on a PCB, 32mm 8x8 display, turned headers for display, headers
for interface.
Wow, price has gone down. Many sellers.
Displays are marked on side with pin 1. Silkscreen is upside down.
Data-in	is on the right. Programming might be easiest when data-in is on
right, but tiling from left-to-right, i.e. connect data lines in reverse
order.
MAX7219/MAX7221 can be cascaded into single long shift register, max 8.

Arduino software:
LedControl - Simple, short (shorter if optimising library). Address any
pixel, row or column, per display only.
Max72xxPanel - subclass of Adafruit's GFX, so convenient to program,
hides the tiled nature and treats display as single big one. Can adjust
to various ways of tiling (rotation, placement/order).


TM1638 7-segment controller, 4x4 buttons, 8-digit display devboard
http://www.aliexpress.com/item/Free-Shipping-TM1638-8-Bits-LED-Digital-Tube-Module-Keyboard-Scan-and-Display-Module/32312121947.html
Many sellers. These have CA displays!! Chip is for CC.
Chip can't be cascaded, individual CS lines.

Arduino software:
TM1638 - Easy to use. Use the version for CA displays (needs bit
flipping), and fix 1 bug.

There are similar devboards with fewer buttons, which have CC displays.
The TM1640 can handle 16 digits, but no keypad (it's used on bicolor
matrix displays).


Holtek HT16K33
http://www.aliexpress.com/item/2016-New-Keyestudio-I2C-8X8-LED-Matrix-HT16K33-Lattice-Module-Black/32685350187.html
PCB, chip, display module (bi-colour?)
Plenty of modules without display.
This chip handles 16 segments, so suitable for bi-colour displays, 13x3
button matrix, I2C max 8 addresses.
Haven't played with it.

Arduino software: available


All the libraries handle display shutdown (power saving) and display
brightness adjustment (to the limits of the controller chip).

All chips are easy to get on Aliexpress, except MAX7221 which is
preferable over MAX7219.

Volker

-- 
Volker Kuhlmann
http://volker.top.geek.nz/	Please do not CC list postings to me.