I tried driving the serial port directly, but it doesn't appear that the 3.3V is enough. I actually tried using the open drain option, with a 1K resistor to +5, and setting the TX invert properly, but still no go. With my PC, at any rate. --=20 Larry Bradley =20 Orleans (Ottawa) Canada=20 On Sat, 2014-04-19 at 13:41 -0400, Byron Jeff wrote: > On Sat, Apr 19, 2014 at 01:10:53PM -0400, Larry Bradley wrote: > > Josh: > >=20 > > Finally got around to UART use on the PIC24F on the Microstick II. My > > biggest problem was getting a terminal emulator working on Linux. Had t= o > > use a MAX232 to interface to my PC. >=20 > I haven't used a MAX232 in quite a while. For the last few years I've bee= n > using a 2 diode/2 resistor external voltage clamp that Olin Latrop > describes in this thread for TX and DTR from the PC: >=20 > http://www.microchip.com/forums/m154654.aspx >=20 > Less than 5 minutes to put in a circuit and works like a champ. Transmit > from the PIC is always tied directly to the serial port. I haven't run > across one in several years that didn't respond to direct TTL/CMOS level > output. Of course I'm still running everything at 5V. Unsure how effect i= f > is at 3.3V. >=20 > I love the fact that the PIC24 UART can be inverted to accept the inverte= d > input signal using the hardware UART too. >=20 > BAJ >=20 > >=20 > > So far just doing output at 9600 baud - all is well. Later on I'll up > > the speed, and try reading from the PC via the UART. > >=20 > > Doing my own handling of the UART, rather than using the Microchip > > libraries, as I like to understand how the hardware works. > > --=20 > > Larry Bradley =20 > > Orleans (Ottawa) Canada=20 > >=20 > > On Tue, 2014-04-15 at 12:04 -0400, Josh Koffman wrote: > >=20 > > > On Tue, Apr 15, 2014 at 9:12 AM, Larry Bradley = wrote: > > > > I would think that 0.25% accuracy would be fine for serial comms - = async > > > > serial is not very demanding. I will be trying some serial comms wi= th my > > > > MicroStick II in the next day or so. I'll post my results here. No= te > > > > that the non-USB versions of the 24F only have a 2% clock accuracy.= But > > > > the 24FJ64GB002 that comes with the MicroStick is 0.25%. > > >=20 > > > Interesting. I am hoping to play with some of the WS2812 LEDs (with > > > built in controllers), which have a bit of an oddball timing > > > requirement, making them tricky to drive on a micro that has a bunch > > > of other tasks to perform. I'm hoping that by using a chip with a hig= h > > > enough instruction clock I will be able to do some useful work while > > > still driving the LEDs. So...MIPS are important! > > >=20 > > > > You can mount the MicroStick on a prototyping board and then use an > > > > external xtal. If you then build a PCB for the final device, you do= n't > > > > need the MicroStick. The main reason I wanted the MicroStick was fo= r the > > > > built-in programmer, so I could play with the 16 and 32 bit chips. = If I > > > > want to get serious, then I can always buy a PicKit III or other > > > > programmer. > > >=20 > > > I have a few PICKits, and I like them a lot. They're small enough tha= t > > > I can take them with me, and as I sometimes do development while > > > traveling, that's a huge bonus. Normally I just use a board from a > > > previous project when I'm trying things out, but as I'm looking to ge= t > > > into higher level PICs, I don't have anything like that yet. Since I > > > want to mess around with them on these projects, I wanted to get a > > > general purpose board that I can play with. I don't think I'll end up > > > using a proto-board, I'll most likely jumper whatever dev board I end > > > up with over to one of my boards. > > >=20 > > > > I'm just a hobbyist these days, so I don't need anything fancy. > > >=20 > > > I'm not looking for too fancy either, just something that works! > > >=20 > > > Josh > > > --=20 > > > A common mistake that people make when trying to design something > > > completely foolproof is to underestimate the ingenuity of complete > > > fools. > > > -Douglas Adams > > --=20 > > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > > View/change your membership options at > > http://mailman.mit.edu/mailman/listinfo/piclist >=20 > --=20 > Byron A. Jeff > Chair: Department of Computer Science and Information Technology > College of Information and Mathematical Sciences > Clayton State University > http://faculty.clayton.edu/bjeff --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .