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I had put some of the final tuning on the back burner for a while, but have ironed out a few bugs and tuned the control gains so it flies decently. It's a large frame with a hefty moment of...

The code is about 1400 lines at this point (probably could/should be shorter - plenty of white space) and definitely not streamlined and would probably offer a wealth of lessons on how not to comment...

Yep, you can do a quadcopter on an 18F chip with PBP. I found this question in a post from a long time ago, but that thread is now closed. I'd been working a quadcopter on and off for maybe the past...

Yeah, that was it. After switching to HS it went from about 800ppm slower than I wanted to about 125ppm faster. The first chip also went from 23ppm slower to roughly 125ppm faster. For clarity,...

I have a timing critical application and am running an 8Mhz xtal with a 16F628a. When I program chip 1 with given HEX code (compiled with PBP), it runs roughly 23 ppm slow. I programmed a different...

Your answer specific to the "// 32" operation was extremely helpful and did indeed result in a significant speed increase. And I very much appreciate it. One of your later replies did address my...

I did implement the "& 31" change, and that did significantly speed it up (output tone increased to ~2400 Hz, which is an order of magnitude increase and the // operation was indeed the main speed...

I'm trying to generate multiple audio tones using a DAC/resistor ladder (currently 4 bit / 16 values - will scale up eventually), but am troubleshooting increasing the speed of this loop for a single...

I posted this question on another website but did not really get a straight answer.

If I have an array of 32 bytes defined in a variable SINB, and I execute the command "ampvar=SINB[lookbyte]",...

I'm about to start tinkering with the rfm69hw, and was wondering if anyone has some example code? The application is to send GPS data from up to 1/3 mile away in wide-open terrain.

I'm also open...

It's using an external crystal with the "HS" oscillator setting.

After adding some caps, the output is much better and it's clearly exporting acceleration data correctly. Flipping it around on...

It was communicating with the terminal program at 9600 baud without a problem... wouldn't it have spouted gibberish if it didn't use 8Mhz? I'll use uppercase to be safe.

But I think I figured out...

I'm having trouble interfacing an ADXL375 accelerometer (almost the same as the more widely used ADXL345 from what I can tell). I would appreciate any help!

The datasheet for the ADXL375 is here:...

Thanks for the responses...

I haven't connected the computer to the GPS rx pin, so that shouldn't be damaged. And I misspoke when I said I had connected the module to an RS-232 port... it's a...

I have a gy-neo6mv2 (ublox NEO 6M GPS) that's regulated to 3.3v. I'm planning on parsing the NMEA sentences with code, but wanted to get a sample of the data before it was hooked up to a pic. After...

Does anyone have any experience with interfacing RFID receivers and active tags that are more for automotive systems? A lot of the chips for tire pressure monitoring systems (TPMS) look particularly...

So how come my older computer could read serial data from a PIC operating at 5V? Was it not "RS232"? I had ground between them connected, so the data line wasn't "floating".

Also, hypothetically...

My old computer had a serial port that I could read 9600bps data exported from a 16F628 operating at 5V without a MAX232 chip. I installed a card with a parallel and serial port on my new computer...

Is it acceptable to connect a crystal oscillator circuit to the supply voltage instead of ground? I've gotten into the practice of doing this because (1) the OSC pins are closer to the supply...

Thanks for all the good comments and suggestions!

The oscillator is a wein-bridge oscillator, and DC drift could be the cause of it. I'll be hooking up an oscilloscope to check this weekend. ...

I'm developing an audio frequency radio modem, and have a problem I was hoping some of the gurus here could help me with. I greatly appreciate any help that can be provided!

In short, the modem...

Thanks! I'm at work and haven't gotten a chance to try it yet, but I noticed you said it would work for "some" 16F chips. Would a 16F628a be included in that group?

Thanks again!
Dave

I remember seeing a post regarding how to measure the elapsed time for some code, but after searching for it I can't find it. My application is for a radio modem, and I need to measure things in the...

Ah ha, that might be it... I have the configuration word set to XT on the pull-down menu (I don't typically set the oscillator type in the program). I guess that should be set to HS. Odd that the...

I'm having some trouble with my crystal oscillator. It worked fine on another 16f628a, but I've soldered some more components to my prototype board (and I accidentally bent the pins on the original...