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Research-Log-Robot-21 PIC-Multi-Servo
OK.
Now, I know something about PIC.
From now on, I am going to build my first application by PIC.
It is a Multi Servo controller.

Project: PIC Multi Servo
16F876 was engaged in this application as the controler of 14 servos.
A0~A5 applys 6 channels
B0~B7 applys 8 channels
C0, C1, C2, C5 were configed as JP1~JP4
Which asigned the base address of the chips and channel as well.
JP1~JP4 asigned the address from 0x00~0xf0, 16 addresses alltogether.
the address of a servo channel could be:
0x00~0x0d
0x10~0x1d
........
0xf0~0xfd
224 channles as all.
All channels applyied FUTABA-PWM output.
It means the control signal is a continuous stream of pulses
that are 1 to 2 milliseconds long,
repeated approximately fifty times per second.
The width of the pulses determines the position to which the servo moves.
The servo moves to its neutral,
or middle position when the signal pulse width is 1.5 ms.
As the pulse gets wider, the servo turns one way;
if the pulse gets shorter, the servo moves the other way.

This prohect support Serial port and I2C bus.
They can work together.

Protocol
1, Mini SSC II (Serial Servo Controller)
The available baud rate is 2400 or 9600 baud.
To set the servo position, send a sequence of three bytes.
The first byte is a synchronization value that must always be 0xff(255)
Byte 2 is the servo number, and it must not 0xff(255).
Byte 3 is the position to witch servo go.
2, AxnSSC(Axnzero Serial Servo Controller)
Fully compatible with Mini SSC II
If the synchronization value are followed with a byte less than 0xff,
It means Mini SSC II was actived,
The second byte is servo number,
The third byte is servo position.
If the synchronization value are followed with another 0xff,
the sequence will be 6 bytes
1  0xff
2  0xff
3  start_servo_number
4  servo_position_high
5  end_servo_number
6  servo_position_low
End_servo_number should be bigger than start_servo_number.
If end_servo_number smaller than start_servo_number,
End_servo_number will be set as equal to start_servo_number.

The advantage of AxnSSC is:
1, Support multi servo move together.
2, Support 16bit motion control 0x0000~0xfeff.(0~65279)

Zhao Xuedong(Axnzero) 20070620
Version 1.0

Research-Log-Robot-18 apply for something

PIC16F628 1
OSC20M 1
C22p  2
MAX232 1
C50V1u 4
C50V100u 2
C104  2
All above for 2~10 groups

LED  50(Dia3mm)
R330om 50(0.25~1W)
R2.2K  50(0.25~1W)
Copper PCB x
Tiny cable x

LCD42005 1~2
Cutter  1
Pliers  1

DB25M 6
DB15M 6
DB9M  6

Research-Log-Robot-15 LCD LPT 8Bit
First test: LPT, 8Bit
Electronic connections:
LPT 2~9-----LCD DB0~DB7
LPT 16------LCD RS
LPT 17------LCD E

2 pieces of 74HCT245 ware inserts between LPT and LCD,
Because the LPT port can NOT drive the LCD interface.
NO 245, NO success!

The initialise bytes are: 0x38, 0x01, 0x06, 0x0f
The testing data are 0x00~0xff

Research-Log-Robot-14 LCD
New project: LCD
Dr. Min Yang gives me a very good chance to test the PIC.
The LCD modular type is: BTHQ_42005VSS-FSTF-06-LEDWhite_2Die
It is branded by BATRON.

General description:
1, 20 characters (5x8 dots) X 4 lines FSTN positive black & white transflective LCD character module
2, View angle: 60’ clock direction
3, Driving duty: 1/16 duty, 1/5 bias
4, SAMSUNG KS0066UP-10BCC (Die form) LCD controller & driver or equivalent
5, SAMSUNG KS0066B-PCC (Die form) LCD segment drivers or equivalent
6, White LED05 backlight

The interface of this module is 14 Pins:
1, VSS (GND)
2, VDD (5V) Power supply for logic
3, V0 (-10V~5V) Power supply for LCD driver.
4, RS Register Select Input. 1 for data register, 0 for instruction register.
5, R/W Read/Write signal: 1 for read, 0 for write.
6, E Enable, Start signal for data read/write.
7~14, DB0~DB7 Data input/output (LSB)
15 (A) LED+ Anode of LED backlight
16 (K) LED- Anode of LED backlight

Research-Log-Robot-13 SSP
Define a Small Serial Protocol for PIC applications.
Block is a set of flag, head, and data.
A block has 3 parts:
1, Block Flag
2, Block Head
3, Block Data

Block Flag is always set as 0x80.
The range of the rest of the data in the block is between 0x00~0x7F.

Block Head have 3 bytes.
The first byte descripts the length of the Block Data.
The second byte descripts the destiny address.
The third byte descripts the source address.
0x00 could NOT be used as device address.
0x00 means broadcast.

Block Data is appearing in pares as higher bits and lower bits.

Research-Log-Robot-10 Back to PIC
Temporary test my PIC on another computer.
I have to build a new link for RS232.
The new hyper terminal forms a new script file for communication.
Parameter: 9600-8-N-1
Flow Control: Hardware
It can’t works!!
When the parameter ‘Flow Control’ was set to ‘None’,
It works again.
Oh yes.
The interface has only 3 lines:
TxD
RxD
GND
No line for hardware flow control.
So, Flow control has to be set to ‘None’.

After all, the PWM program works.
It works.
It really works!
With RS232 interface, interrupt operation mode,
The PIC output excellent PWM signal,
And the servo works properly.
And the servo works with the small manipulator properly.

Now, I am happy.
I am really, really happy!