Universal µC Control
by Martin Clausen (mc AT rotgradpsi DOT de)
This circuit employs MCU to control up to eight voltages each device via knobs and LCD or RS232.
- Standalone operation or operation with other controlling devices
- up to 255 devices cascadeable, also compatible with the whole control familiy
- Up to 8 independent outputs each device
- Values from 0 to 4095 selectable
- Timing ready for usage of optocouplers for galvanic separation (30µs delay between all signal changes)
- 16*2 LCD
- Equal steps while tuning value with rotary encoder
- Value reset button
- All commands from the computer pass through with a delay of only 29µs plus send time of one character, while no key is pressed
- 128 bytes buffer
- RS232 interface, 8 databits, no parity, one stopbit
- Supported baudrates: 115.2; 57.6; 38.4; 19.2; 9.6; 4.8; 2.4 and 1.2 kbps
- Line end character: CR; other possible, please send me a mail
- Prepared for Serial program version information system
- Program is freeware for non-commercial use.
The device utilises LTC1257 to allow the user to control digital up to eight voltages. It can operate on its own or in connection with a computer. All commands from the PC are passed through. If the device receive a command with it own address, it will also set the voltage as required. All commands end with a line end character. This is normally CR.
Address, line end character and the number of outputs can be changed easily, just send me a mail with your demands.
Press sel during powerup to step through the program version information.
Baudrate Selection
| MSB - LSB | Baudrate / kbps
|
|---|
| 111 | 115.2
|
| 110 | 57.6
|
| 101 | 38.4
|
| 100 | 19.2
|
| 011 | 9.6
|
| 010 | 4.8
|
| 001 | 2.4
|
| 000 | 1.2
|
Meaning of 1 and 0 in this table:
The baudrate jumper are read up on reset.
n ist the number of outputs
- Semiconductors:
- 1 AT89C52 or AT89S52, 24MHz; see also programming tips
- 1 MAX232
- 1 16*2 LCD
- n LTC1257
Capacitors:
- 1 1µF / 25V axial
- 6 10µF / 25V axial
- 2 33pF cer
- n+1 100nF cer
Resistors:
- 1 10k*8 / 9 pin sil array
- 1 10k trimmer
Mechanic:
- 1 22.118MHz crystal
- 1 rotary encoder Bourns ECW1JB24AC24 or 2 additional buttons (for encR and encL)
- 6 buttons
- 2 sub-D socket, 9 pin
- 1 dip switch with 3 switches
- 1 case
- 1 pbc
- 1 some thin wire
- 1 socket 16 pin
- 1 socket 40 pin
- 1 loop back plug (9 pin plug with only pin 2 and 3 connected to each other) for the last controller in a chain only
The part description in schematics is read as follows:
part type + value in exponential form + package description + subpart number in package
for example: C1040805,1 means Capacitor, 100nF, package SMD 0805, first subpart in package
Disclaimer: No warranty at all!
Copyright by Martin Clausen, Germany.
Contact the author: mc AT rotgradpsi DOT de
Impressum
