Hi Seb, Mostly I used a simple but effective reset circuit, just connect the CTS line with a 10uF capacitor with the reset line (and using a diode + 10K resistor to pull up the reset line). The cap only initiates a pulse when the CTS line is changed from high to low, the reset line will be pulled high after a couple of milliseconds even when the CTS line stays low. Albert
----- Original Message ----- From: "Sebastien Lelong" <[email protected]> To: <[email protected]> Sent: Thursday, August 13, 2009 9:00 PM Subject: [jallib] Re: jaluino (resetting via RTS) I tried to prototype the "reset using RTS" thing on a breadboard, but I got troubles (as expected...). I followed the schematic and connected D2, R2, R3 and Q1 onto the breadboard. It's as though it's acting the reverse: when I plug the serial module, it keeps resetting the PIC. When I plug the serial module: - Vrts ~ 4.1V (5V without hardware D2, R2, ...) - PIC doesn't blink the LED (keeps resetting) For my tests, I used python serial module: import serial ser = serial.Serial(port="/dev/ttyUSB0",baudrate=115200) by default, when the serial connection is created by this command, RTS = 1, and Vrts ~ 0V. The PICs starts ! ser.setRTS(1) -- will reset the PIC, Vrts ~ 4.1V ser.setRTS(0) -- will start the PIC, Vrts ~ 0V So, it seems to work but on the contrary expected behavior. I would expect that by default the PIC starts. Does it seem weird to you too ? Or did I miss something ? Cheers, Seb > > > > > > Also ask by Seb is the reset option by RTS (J7). > > > > OK this is where I'm lost... I have few questions about this: > > > > - RTS and CTS in serial connector are connected to RD5 and RD4. Why ? > > > If you want handshake you can use RD5 and RD4, if you dont need > handshake you > Can use RD4 and RD5 on connected I/O4 > > > > - when I want to reset the board using RTS, I need to switch RTS J7 > > trigger to position 1-2, as in the schematic. Is that right ? > > Yes, if you put it in position 2-3 you cant use reset but you can use > handshake. > If I did not use the switch (is jumper) than you could not use RD4 as > normal I/O > because PIC would reset as soon as RD4 becomes high. > > > > - All the serial modules I've used or built have their RTS connected > > to > > CTS. No flow control, quite common I think. Like in this article: > http://www.lynxmotion.com/images/html/build125.htm. Now imagine I use such > > a module with RTS and CTS connected. I plug it to the board. Will this > work > > ? Or should RTS and CTS remain unconnected from each other ? In that > case, > > do I have to deal with flow control ? (hope not...) > > Yes this will work and No you dont need flow control, but like in > your link dont connect the RTS end CTS from the serial module to the > serial connector of the Main Board else you cant use RD4 and RD5 for > other purpose. > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "jallib" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/jallib?hl=en -~----------~----~----~----~------~----~------~--~---
