LED banner wall

LED banner wall

Participants	Bjornl
Skills	Programming, electronics, Arduino
Status	Operational
Niche	Electronics
Purpose	Infrastructure
Tool	No
Location
Cost
Tool category

LED banner wall

2013-07-02_23.08.34.jpg {{#if:No | [[Tool Owner::{{{ProjectParticipants}}} | }} {{#if:No | [[Tool Cost::{{{Cost}}} | }}

Small sign

Yotson modified a small LED banner sign to be controlled by an Arduino. After hooking it up to the Dockstar and reprogramming SpaceBot it is now stored somewhere. Code is available on github, based on this earlier code.

15/12/13

Petraea dragged the sign out to give it a little dusting down to find that a bunch of columns no longer worked(See inset animation) A little digging around identified that the CLK line was broken, so a simple extra wire was fitted to repair this.

Large sign

DeDaan brought in a larger sign. This used to work at the previous location.

Current status

Works! It is hanging above the door from bar to Zaal 1. There's a raspberry pi connected to it, with hostname hetisbar.dhcp.nurd.space. Port 5001 udp receives text. Root-account is the usual password. If it doesn't work, reboot it using the reboot command. Sometimes it does lose connection to the arduino of the banner (no /dev/ttyACM0 appears).

Port 5003 listens to pixelflut (UDP!).

home assistant integration

Hardware

The sign consists of 18 smaller panels of 5x7 pixels each, arranged side by side.

Software

Source code:

https://github.com/flok99/BigLedPanel

Protocol

The protocol between the Raspberry pi and the led banner is as follows:

The Raspi sends raw frames over serial at 9600 bps, each column in one byte, 7 bits per byte, from left to right. A frame starts with code 0x80, then 90 bytes of raw column data.

old

https://github.com/NURDspace/BigLedPanel
https://git.nurd.space/bigledpanel/bigledpanel/ (new location)
First try https://gist.github.com/zarya/10f47d6b3097643f4016
It starts to work https://gist.github.com/zarya/33fe46dac38b89f84d60
last current code https://gist.github.com/zarya/24b3b56be5c432334539

First images

Finaly some text
Static text printed from the framebuffer
Het hangt

Schema's / Electronics

Arduino Pin setup

PORT_D
 0 (PD0) - UART RX
 1 (PD1) - D5
 2 (PD6) - D3 A0
 3 (PD5) - D4 A1
 4 (PD4) - D6 A2
 5 (PD3) - D2
 6 (PD2) - D0
 7 (PD1) - D1
PORT_B
 8  (PB0) - MR
 9  (PB1) - E1
 10 (PB3) - E2
PORT_C
 14 (A0,PC0) - A0
 15 (A1,PC1) - A1
 16 (A2,PC2) - A2

PIN OUT

01 - VCC
02 - VCC
03 - VCC
04 - SN74LS273N PIN 1 (MR)
05 - SN74LS138N PIN 5 (E2)
06 - SN74LS273N PIN 4 (D1)
07 - SN74LS138N PIN 1 (A0)
08 - SN74LS273N PIN 3 (D0)
09 - SN74LS138N PIN 2 (A1)
10 - SN74LS273N PIN 7 (D2)
11 - SN74LS138N PIN 3 (A2)
12 - SN74LS273N PIN 17 (D6)
13 - SN74LS138N PIN 4 (E1)
14 - SN74LS273N PIN 13 (D4)
15 - GND
16 - SN74LS273N PIN 8 (D3)
17 - GND
18 - SN74LS273N PIN 14 (D5)
19 - GND
20 - GND

Old info

The larger sign contains a separate control unit, programmed using a separate keyboard with a DB-9 like plug. It is attached to a PCB containing the LEDs with a 20 pin flatcable.

The control unit ( http://www.flickr.com/photos/bjornlammers/8425066292/in/photostream ) contains the following ICs:

NEC D8049HC 195 (pre-programmed CPU)
Motorola SN74LS373N ( http://www.alldatasheet.com/datasheet-pdf/pdf/5714/MOTOROLA/SN74LS373N.html )
Toshiba TC5517APL (Static RAM, probably where the program is stored)
unmarked IC, probably an EPROM

The Toshiba and the unmarked IC are in a socket, the other two are soldered to the PCB.

The LED panel ( http://www.flickr.com/photos/bjornlammers/8425075284/in/photostream ) contains:

6 * SN74LS273N ( http://www.alldatasheet.com/datasheet-pdf/pdf/5696/MOTOROLA/SN74LS273N.html )
6 * uA9668PC ( http://www.alldatasheet.com/datasheet-pdf/pdf/102338/FAIRCHILD/UA9668PC.html )
1 * SN74LS138N Decoder/demultiplexer ( http://www.alldatasheet.com/datasheet-pdf/pdf/5654/MOTOROLA/SN74LS138N.html )
2 * DM74LS259N 8-Bit Addressable Latches ( http://www.alldatasheet.com/datasheet-pdf/pdf/51060/FAIRCHILD/DM74LS259N.html )
4 * unmarked IC

See also this tech-archive thread: http://sci.tech-archive.net/Archive/sci.electronics.repair/2012-06/msg00302.html