PIC32MX695F512L - Device Detected: Unknown - When programming

[chris11jed]

Hello MikroE Mods,

I am having trouble programming a PIC32MX695F512L on a custom board with my mikroProg. Could someone take a look and maybe help?

mikroProg Error Message:

Device detected: Unknown!
Device selected: PIC32MX695F512L
Continue anyway?

MikroE Software/Hardware Specifics:

• mikroC PRO for PIC32 v4.0.0
• mikroProg Suite for PIC v2.90
• HW: mikroProg v01.16.12.21

The PIC32695F512L is on a custom board. I followed this as my guide to the schematic: easypic fusion v7 PIC32MX4 MCU Card Manual V100

MCU Scematic Design:

PIC32MX695F512L MCU Connections Schematic.pdf

(191.32 KiB) Downloaded 31 times

Board Layout Design:

PIC32MX695F512L Board Design.pdf

(183.64 KiB) Downloaded 35 times

Image of Board with mikroProg attached:

PIC32MX695F512L Physical Board Layout with mikroProg attached.jpg (116.42 KiB) Viewed 867 times

Things tried:

• Programming two PIC18F87K22 MCU's on custom boards. Result: Programs fine.
• Checking power to the custom board, and to PIC32MX695F512L. Result: +3.28V
• Programming with board power on. Result: Get error.
• Programming without board power. Result: Get error.
• Taking LCD off board, disconnecting ribbon cables to peripherals, and unplug keyboard. Result: Get error.
• Each attempt, the DIL switch next to the mikroProg header named 'Bypass' is switched 'off' (These switches, as seen in the MCU schematic, act as links between the MCU trace and the rest of the circuit. Having them switched to 'off' allows the mikroProg header to work.). Result: Get error.

Hopefully someone might see something, or come up with something, to try out.

Thank you.
Chris

[MicroMark]

Hi, one problem I see on the pcb is Vcap pin 85. On your board you have it connected to vdd. It should only connect to one side of the 10uf cap. The other side of the cap should be connected to vss. You can verify this in the datasheet under "minimum connections". I had the same problem once that drove me crazy. One side of the vcap lifted off the pcb and was unconnected. The programmer would not recognize the chip.

Good luck

[chris11jed]

Hi MicroMark,

YOU SIR, ARE A GOD-SENT!!!!

After some surgery where I de-soldered the 10uF cap, scrapped back some of the black coating off the trace, used a dremel to cut the trace between pin 85 and the vdd very carefully, cleaned everything, I then resoldered the 10uF cap 90 degrees on its GND pad. Then used two strands of some 13-strand x 0.12mm tinned hook-up wire (twisted together) to bridge the vcap trace and the other end of the 10uF cap. Man! It looks ugly-ish, but got it all done!

AND THE CHIP NOW PROGRAMS FINE!!!! Woooooooooooo!!!!

So, I am not sure why I connected Vdd to the Vcap capacitor in my schematic? Mental lapse? Not sure. But, the link I gave, and you gave, clearly shows the cap to gnd and just the vcap pin
Anyway, really good to have someone spot this mistake!! Am so over the moon right now. Can not thank you enough! Was the answer I'd been sweating, praying, hoping on, haha!

Now I just need to fine-tune how to make this PIC32 chip do what I want it to do. Which is a whole other post, haha. But, now, at the very least, I can flash the thing. Which is terrific!

Thank you so very much!!!

[MicroMark]

Good going, glad you got it running!