Renewable Energy Innovation

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For a couple of recent projects we have been asked to provide interesting and informative display units. We decided to build a unit which can be used in a number of different applications. It was designed to look good, be able to show graphics and text, have a couple of switch inputs and be configurable for a variety of uses. The end result was so useful, we decided to produce this design and a kit of the main parts.

 

The unit comprises:

  • LED dot matrix display
  • Microprocessor
  • Interface PCB
  • Acrylic hardware

LED dot matrix display

We are using a 32 by 8 LED dot matrix supplied by Sure electronics, based in Hong Kong. They also have an eBay shop. The price ranges from $8 to $16, check eBay first.

More information about using the LED dot matrix display can be found in this blog post.

Microprocessor

To keep development time to a minimum, an arduino is used as the 'brains' of the unit. This is a development board based upon the ATMEL 328 microprocessor chip. Our units use the less-expensive Xino, an arduino clone from Ciseco. Any Arduino compatible board should fit into this display unit (except the MEGA range).

There are numerous open-source examples available for the arduino, hence development time is very short. We have developed a simple clock unit with temperature history display as a sketch to get you going with the use of this display, but the final use is left up to your imagination.

Interface PCB

A specially designed interface PCB has been produced for this unit. There was some extra space on the interface board, so we decided to add a number of components which might be useful for your project. These include:

Prototype PCB

The prototype PCB has just bee made and tested. While it did not work first time, with a few tweeks the unit is working well. Here are some photos:

 

Disconnected boards - Sure LED display, my shield prototype PCB including XRF module,and Xino, the ardunio clone

The XRF can be seen with the white antenna. The coin cell battery keeps the real time clock running.

As usual with a prototype - there were a few wiring changes required...

We now need to produce a production double-sided PCB.

Here is the final circuit diagram for the board:

Right click to save the image for higher quality.

Parts list

Schematic REF Component Value
BT1 BATTERY 20mm coin cell
BZ1 BUZZER Piezo element
C1 CAPACITOR 100n
C2 CAPACITOR 10u
C3 CAPACITOR 100n
C4 CAPACITOR 100n
D1 DIODE 1N4001
D2 DIODE 1N4001
D3 DIODE 1N4001
MOD1 WIRELESS MODULE XRF-00
P1 CONNECTOR BATT
P2 CONNECTOR CHARGER
P3 CONNECTOR CONN_8X2
P4 CONNECTOR CONN_6
P5 CONNECTOR CONN_6
P6 CONNECTOR CONN_8
P7 CONNECTOR CONN_8
R1 RESISTOR 5R 3W
R2 RESISTOR 10k
R4 RESISTOR 10k
R5 RESISTOR 10k
R6 RESISTOR 1K
R7 RESISTOR 1K
SHIELD1 ARDUINO_SHIELD
SW1 POWER SWITCH SPST
SW2 INPUT 1 SW_PUSH
SW3 INPUT 2 SW_PUSH
U2 REAL TIME CLOCK PCF8563
U3 3v3 REGULATOR MC1703
U4 TEMP SENSOR MCP9701
X1 WATCH CRYSTAL 32.78kHz

And the PCB design layout.

****kicad PCB - TO DO, not yet finalised***

Acrylic hardware

The hardware is mainly two pieces of frosted acrylic plastic which are cut out using a CNC machine. The Xino and LED display bolt onto the plastic and spacers are used to hold the two pieces of plastic together.

The design for the plastic was produced using HeeksCNC, the design file is available here. The output g-code is used on our desktop CNC machine run on an Ubuntu machine using EMC2.

Kit of parts

Note: The kit is not quite in production yet - please This email address is being protected from spambots. You need JavaScript enabled to view it. if interested.

These are the parts required for this LED display unit:

***image of parts***

Prototypes of this design have been used in our solar race timer and remote power and energy display.

Please This email address is being protected from spambots. You need JavaScript enabled to view it. if you are interested in purchasing a kit of all the bespoke parts.

To Do

This project is a work in progress. This is a list of essential and useful changes which need to be made:

  • Change 3v3 regulator PCB module - done 30/6
  • Use 3v3 as Vref and for temperture - done 30/6
  • 1mm holes for buzzer, 20mm battery clip, through-pins for shield - done 30/6
  • 1.5mm holes for battery connector - done 30/6
  • Remove pull down resistors from RTC - done 30/6
  • PCB mounting switch for power - found, need PCB design - done 5/7/11
  • Shorter capacitor (it hits the LED display) - done 30/6
  • Move regulator away from 20mm battery clip - done 30/6
  • Pull up resistor for pin 3 RTC - done 30/6
  • Move switches 5mm to right - not doing this 30/6
  • Find good switches for PCB mounting (long switch heads) - not using those switches
  • Make switch connectors points - done 5/7/11
  • Make PCB shorter - done 5/7/11
  • Redo PCB as double sided - done 5/7/11
  • Order PCB prototype - done 5/7/11 from Spirit PCB
  • Build PCB prototype
  • Test PCB prototype
  • Order real PCB
  • Put up kicad PCB files
  • CNC files - finalise hole positions

Comments   

 
#3 byju.t.k 2016-03-01 08:32
I want one kit
 
 
#2 Matthew Little 2013-06-24 12:36
Quoting Guest:
Sarei interessato alla realizzazione di questo kit.
Grazie per una cortese risposta, Giorgio Smith


I am sorry but this kit is not yet available but hopefully there is enough information here to build your own. Regards. Matt

Mi dispiace, ma questo kit non è ancora disponibile, ma si spera ci sono informazioni sufficienti qui per costruire il proprio. Saluti. Matt
 
 
#1 Guest 2013-06-24 09:40
Sarei interessato alla realizzazione di questo kit.
Grazie per una cortese risposta, Giorgio Smith
 

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