Search Results

Most of my dsPIC3 application is written in C, but one function is particularly speed sensitive, so I had to write that function in assembler. The function looks roughly like this: _FunctionName: lnk …

Apparently this is caused by some kind of partial failure of the chip. I swapped out the part, and the problem has gone away. Turns out it was the hardware after all ;)

I don't know if the PIC can take 40MHz in. Normally we use a 10MHz oscillator and use the PIC's internal PLL to increase it to 40MHz. …

So, whenever I'm writing PIC C, I always check the assembly output to see if it looks sensible. And then, usually, write macros to perform the operations. …

Turns out the answer should have been obvious from the waveforms above. When TX goes low, so does RX. But when TX goes high, RX takes more than 1us to rise again. That's more than a whole bit time! CA …

I am running a short (2 m) CAN bus with about 20 nodes. 1 Mbit/s speed, PIC 18F2580s and 18F4580s with MCP2551 transceivers, 10 MHz (with PLL to 40 MHz) crystal oscillators. …

I am trying to get the ECAN functionality working on a dsPIC33. I have two identical dsPIC33s, each with identical CAN transceivers connected by a short (3 inch) bus. One is transmitting, one is recei …

The PIC is supplied with regulated 5v. Strangely, this problem only seems to manifest if I use 0v-5v input signals. If I use 0v-3.3v inputs, the problem seems to go away. … Is there any strange electrical property of a PIC which can make it miss read a port pin 1% of the time? …

I discovered the answer, and I feel stupid. Turns out that, while in MPLAB C you can write 0b11110000, in MPLAB ASM, you have to write B'11110000'. But the assembler wasn't warning me about this.

Buy it, it's less than a tenner! The parts alone will cost you more than that. Plus the amount of time you spend trying to get it working will make you wish you'd bought it.

I am having trouble getting a simple PWM output to work at all on a PIC32MX775F512H. Looking online, this seems to be all I need to get something working: int main(void) { SYSTEMConfig(SYSTEM_FRE …

I just can't get my PIC12F1822 to switch to 32MHz (8MHz + 4xPLL) I am telling OSCCON to switch to 8MHz, but, according to the debugger, that value is never loaded into it! I also wait for the High Spe …

For some reason, I2C seems to be very confusing and poorly explained in datasheets. Plus the master tends to be very picky about you using it correctly, and the slave is likewise picky. Rightly so, I …

One good way to answer questions like this is to use MPLAB's simulator. If you enable the stopwatch you can see exactly how many CPU cycles, and how many microseconds everything takes:

I tried various optimisation options, but nothing made the compiler produce sane code. I have had similar experiences with the C18 compiler too. Some of the code it generates it amazingly daft, and I …