This is a project included in a series of projects ive decided to start, to reduce the hadware set up time for prototype developing.
This one is a shield for the Arduino boards.
It has eight LEDs each one with a 470Ω resistor in series to pins zero to seven, also known in arduino has digital outputs.
Then it has four push buttons, each one with a 10KΩ resistor pull-up, meaning this buttons are ON with 0V its a negated input (Ī), also each button has a 10nF capacitor to GND that works has debouncing, thus a debouncing subroutine is optional to the buttons.
Connected to digital output 13 there is a 1KΩ resistor that drives a BC817 NPN transistor which grounds a buzzer, theres is also a small capacitor between the buzzer pins to filter bouncing.
Placing and parts list :
BOM (Bill of material) :
REFERENCE VALUE PACKAGE
R1, R2, R3, R4, R5, R6, R7, R8 --- 470Ω R0805
R9 --- 1KΩ R0805
R10, R11, R12, R13, R14 --- 10KΩ R0805
C1, C2, C3, C4, C6 --- 10nF C0805
Q1 --- BC817 SOT-23
LED1, LED2, LED3, LED4, LED5, LED6, LED7, LED8 --- LED KA-3528ASYC
S1, S2, S3, S4 --- Button B3F-10XX
S5 --- DS18S20 3 pin Socket
S6 --- Buzzer
In the S5 there is a socket for 3 pins packages usually TO-92, being pin 1-GND, pin 2-DATA and pin 3 connects to SJ1 which is a jumper to be connected to either GND or VCC, in case of 1 Wire devices if you connect SJ1 to GND the device will work in parasitic mode, getting power from the DATA line, otherwise you connect it to VCC to get the device powered.
Most of the components can be found in farnell, But if you really want to build this and run into problems, you can always contact me, i still have a lot of spare parts.
I have made the PCB with the Osh park service, here is the clean and built PCBs :
The PCB is also available to be ordered from here Osh park shared project.
And here is a final picture of the board connected inside a box.
Check now revision B of this board.
Last but not least a nice video :
Have fun and good prototyping.