Set64RS-Temperature-Controller: Difference between revisions
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*Why does the TXEN line go to the rs-485 circuit? direction control? | *Why does the TXEN line go to the rs-485 circuit? direction control? | ||
**Most likely the 18.432 xtal is the timing oscillator for serial bus | **Naming convention **TXEN** is suspicious = Transmit Enable ?? > most likely | ||
**Most likely the 18.432 xtal is the timing oscillator for serial bus. 18.432 / 1920 = 9600 baud | |||
**Most likely the TXEN controls flow and RA4 is used as in input output pin for this and not to connect to timer0 | **Most likely the TXEN controls flow and RA4 is used as in input output pin for this and not to connect to timer0 | ||
Revision as of 15:01, 13 December 2009
Set64RS notes
Main Board
- CPU chip = 16F76-I/SO
- RC6 / TX / CK > pin 17 - TX Goes to 485 circuit
- RC7 / RX / DT > pin 18 - RX goes to 485 circuit
- RA4 / T0CKI > pin 6 - TXEN goes to 485 circuit ( T0CKI = Timer 0 Clock input )
PIC chip > 193 bytes RAM / 4096 words of program memory
CD4051B - 8 channel mux / demux
74hc164
24LC64 > 64 kbit serial eeprom 9 ( 8 kbytes )
crystal frequency = 18.432 MHz > 1920X 9600 baud
Comments
- Why does the TXEN line go to the rs-485 circuit? direction control?
- Naming convention **TXEN** is suspicious = Transmit Enable ?? > most likely
- Most likely the 18.432 xtal is the timing oscillator for serial bus. 18.432 / 1920 = 9600 baud
- Most likely the TXEN controls flow and RA4 is used as in input output pin for this and not to connect to timer0