Wow.. can you believe it?! I managed to write two компютриPIC24 tutorial pieces in a week!
To tell you the true, the river levels are coming down and I haven’t been kayaking too much. I guess it’s good in a why because there’s so many article I want to write, but just can’t find the time!
Anyways, I posted another section on the I2C tutorial, this time detailing the functions for sequential read and sequential write. The last part of the tutorial should be up next week, where I will dissect an example to show how the I2C can work in a real application.
I’m starting the fiddling process and am moving my normal development platform from a PIC16F690 to a PIC24FJ64GA002 for various reasons. It’s like to start by saying that your tutorial is fantastic. However, I have a couple of questions / comments and I’m not sure where to post them.
A few housekeeping things. I think that you have the data and clock lines switched in your simple schematic in the first part of the tutorial. Also, the link at the bottom of the “Getting Started” page has an extra “http:” in it and is breaking.
My real question boils down to this. I’m having trouble writing to the chip. I’m using a ICD2 clone, and I’ve never had any problem with it and any of the 12, 16, or 18 series chips. This is my first adventure into the 24-series PICs. As you suggested, I hooked up programmer, pulled MCLR high with a 10K resistor, used bypass and filter caps…but the key was that I supplied 3.3v from an external source (not from the ICD2). However, even with all of those steps taken, It is timing out during the verification stage. I can connect to the PIC, set Vdd, do the typical startup things and get to a “ready state; however, verification of program memory hangs every time.
Do you have any thoughts as to how I might be able to fix this? I appreciate it.
Will there still be an example demonstrating these functions for a clearer understanding?
thanks for the info! It is very useful.
Thanks for the comments.
Unfortunately, it’s crunch time for my company right now, and I’ve sorta lost interest in maintaining the website somewhat. As for the I2C, I could probably write something about it soon. Actually the hosting bill is coming up, and I don’t know if I want to pay for another lease… hehe.
To “ben” who’s having trouble with programming the PIC24:
The ICD2 is pretty sensitive to cable lengths. In particular, if your external oscillator is extremely fast, and the cable connecting your ICD to your circuit is very long, the ICD sometimes have trouble programming. Make the cable shorter than 6 inches, and try to keep your external oscillator below 10MHz. That usually works very well. As for the ICD2 clone, I don’t know if it’s a hardware problem. I use the ICD2, and it works great, from the PIC18′s to the PIC32′s. Since you are powering your Vdd_3_3v from an external source, check with the oscilloscope that it is free from any ripples (actually you are SUPPOSE to power it from an external source, the ICD just verifies the Vdd. What I mean by this is, bypass the input voltage with at least one 0.1uF cap and a 10uF cap. Next check that the voltage on the Vddcore is free from any ripples. This should tell you if your power supply is the culprit.
-J