Fabrication by electrodeposition

An open-source equipment for thin films fabrication by electrodeposition, dip-coating and S.I.L.A.R.

ELECTRONIC SUPPORTING INFORMATION

M. Congiua), F. Deckerb), D. Dinib), C.F.O. Graeffa)

a) UNESP – Univ. Estadual Paulista, POSMAT - Programa de Pós-Graduação em Ciência e Tecnologia de Materiais, Av. Eng. Luiz Edmundo Carrijo Coube14-01, 17033-360 Bauru, SP, Brazil

b) DC-FC - UNESP – Univ. Estadual Paulista, Av. Eng. Luiz Edmundo Carrijo Coube14-01, 17033-360 Bauru, SP, Brazil

c) University of Rome ''La Sapienza'', Department of Chemistry, Piazzale Aldo Moro 5, Rome, RM, Italy

Mirko Congiu, corresponding author

Email: mirko.congiu@fc.unesp.br

Phone:  +55-14-3103.6084, r. 7662

Mobile: +55-14-981402118

1. ELECTRONIC CIRCUIT

In the following figure 2 (Fig. 2), the electronic circuit is represented schematically. As shown in the scheme, the RS232 trans-receiver (MAX232) is connected to the digital pins Tx and Rx of the microcontroller.  The instrument is controlled by three push buttons connected to three digital pins. The user can set-up the deposition procedure through the buttons and the LCD (2x16). In this example, the two axis clamp is driven by two servo motors connected to the digital pins. The microcontroller used in the example (ATmega328) has 14 digital input/output pins. In the configuration shown, just the pin 13 remains free after all of the connections. In this case this pin can be used to connect thee clamp´s opening and closing system which could be another servo motor or, as reported in the paper, an electromagnet.

[pic 1]

Figure 2: Schematic view of the electronic circuit used in a simple configuration of the equipment. Notice that the scheme can be modified if a more complex configuration has to be implemented.

A smart alternative, to have three more digital pins, is the use of a button ladder (Fig. 3), connected to one of the analogic pins.

[pic 2]

Figure 3: Configuration of a button ladder to avoid the use of digital I/O pins. This configuration use just one analogic I/O pin.

In this way the digital pins used to control the buttons (Fig.2) can be used to connect other devices. In the software, the pushed button event is associated to a measurement of voltage between the analogic port and the ground. This solution could be very interesting in the case of a more complex project. Notice that other microcontroller with higher number of pins can be used in this project for example the ATmega 2500 which has 54 digital I/O pins. Furthermore, the use of more push buttons could simplify the programming code.  

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