Hardware notes


-This page is a stub
- This page is meant for random hardware notes



Attenuator-amplifier
This is simple preamplifier, and also attenuator. R1 is in reality variable resistor (10kiloOhm). in this simulation it is turned to zero ohm and input signal is around 1 uV. If turned to higher resistance, circuit acts like attenuator...
R4 is only for simulation, to check output voltage at 50 ohm system. In right simulation red is input signal and blue output, both voltages.
I happend to have BC549 in junk box, which is kind of low-noice-high-gain version of very common BC548 or BC 547.
In real life R1 is potentiometer with switch, which act like power switch of this...umh...attamplifier.

You may ask why to attenuate first and then amplify...it is a good guestion. It is just one of those general building bricks.
preAmp.png

LCD wiring

- LCD module type is "Topway LM12864MBC"

-Wiring: LCD panel is type "B" at GLCD-documentation (GLCD is arduino library)

LCD pIn
LCD pin number
ArduinoPin number
Description
GND
1


PWR
2
+5v
Yellow1
LCD contrast ref.
3


RS
4
23
Orange1
R/W
5
25
Red1
E
6
27
brown
DB0
7
29
Black1
DB1
8
31
Yellow2
DB2
9
33
Orange2
DB3
10
35
Red2
DB4
11
37
Brown2
DB5
12
39
Black2
DB6
13
43*
Yellow3
DB7
14
41*
Orange3
CS1
15
45 * *
Red3
CS2
16
47 * *
Brown3
/RST
17
49
Black3
VOUT
18


BLA
19


BLK
20






-*Note wiring is inconsistent, accidentally
-** Note I had to switch these pins (in file ks0108_Mega.h) to get lcd work properly.


Keypad wiring

byte rowPins[ROWS] = {30, 28, 26, 36}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {22, 40, 38}; //connect to the column pinouts of the keypad

Keypad pin
arduino pin
Description

1
30


2
28


3
26


4
24
re-dial

5
22


6
40


7
38


8
36


9
34


10
32
call

Keypad pin number = when watched from button side (in front of keypad), and from left to right.
(Please note that keypad used here is unusual, couple of buttons are wired separately.)

txmeter2.png