Unable to detect PIC32 or PIC24 using adaptor board  - Page 1
Forum section: electronics / general

author: diyaudio
author_rank: Frequent Contributor
timestamp: February 23, 2014, 03:27:19 pm
content: HiI soldered a PIC-32MX795F512L and PIC-24FJ128GB210 adaptor boards, one 0.5mm and one 0.4mm respectively the 0.4 was the most challenging (its the first time I soldered a high pin 0.4mm pitch 100 pin device it wasn't to bad as I used a usb microscope.The problem is I cant get "none" of the devices to detect I even tried to re-solder both boards just in case I missed some leads, still nothing?? Has anyone had any success using these adaptor boards ??I got my PICs from microchip direct the boards I bough off ebay they quite common.Using a genuine PICKIT-3 and MPLAB even tried the MPLAB IPE still nothing.Any advice will be highly appreciated.

author: hans
author_rank: Super Contributor
timestamp: February 23, 2014, 04:04:14 pm
content: Make sure all pins have decoupling caps.Make sure there is a (preferably) ceramic cap on Vcore, and the regulator is not disabled. Some parts have enable vreg, some have disable vreg. Very easy to mess up, make sure it isn't floating too. Measure the voltage and verify them against datasheet (most of them are 2.5V I believe)

author: hli
author_rank: Frequent Contributor
timestamp: February 23, 2014, 04:06:10 pm
content: Also, make sure all ground and power supply pins are connected.

author: diyaudio
author_rank: Frequent Contributor
timestamp: February 23, 2014, 04:41:59 pm
content: Quote from: hans on February 23, 2014, 04:04:14 pmHi,1) All the pins have ceramics 0603 ceramics soldered 100n, 0.1uf caps.2) Not sure about the regulator disabled.3) I measured 2.5v and 3.3 respectively 3.3 on the supply (sourced from the PICKIT).I will measure the voltages again.

author: diyaudio
author_rank: Frequent Contributor
timestamp: February 23, 2014, 04:44:24 pm
content: Quote from: hli on February 23, 2014, 04:06:10 pmThe power is directly sourced from the PICKIT-3, all power connections connected via the adaptor board.

author: dannyf
author_rank: Super Contributor
timestamp: February 23, 2014, 04:47:45 pm
content: Make sure that you follow the power requirements on the datasheet.Also, some PIC chips (24F at least) have defective PGc/d pins: read the errata to be sure.

author: diyaudio
author_rank: Frequent Contributor
timestamp: February 23, 2014, 05:01:36 pm
content: Quote from: dannyf on February 23, 2014, 04:47:45 pm@dannyf I will check the datasheet errata as well, so many pins so much room for error.

author: hli
author_rank: Frequent Contributor
timestamp: February 23, 2014, 05:03:22 pm
content: The PIC32MX795F512L needs at least 10µF on its Vcap/ Vcore pin, low ESR. Also, a bulk capacitor for Vcc is recommended. (see its DS, table 31-15)

author: hans
author_rank: Super Contributor
timestamp: February 23, 2014, 05:25:51 pm
content: To rule out it's an error with the adapter board(as you asked for experiences), is the ISP header connected correctly? Beep them to verify you got the right VCC/GND/PGC/PGD/MCLR pins, and check the PGC/PGD pairs.PIC24 had a buggy PGC/PGD pair in some parts (as Dave explained in a video about his uCalc/uWatch project). I don't see it in the errata for the PIC32 though, so I suspect the ISP pins may not be wired correctly or at all. Maybe it's just there so you can solder wires on the pins to the right outer pads.Or maybe there is a short on MCLR/PGC/PGD to GND/VCC?2.5V on the Vcore pin is good. I've used cheap 10uF aluminum caps before on a dsPIC33 and it was fine. So if there is any 10uF cap there, I would expect it to work.

author: diyaudio
author_rank: Frequent Contributor
timestamp: February 23, 2014, 05:32:03 pm
content: Okay I "Might" have found the issue here..The adaptor has PIN -30 OPEN circuit for the analogue section. The data sheet says other wise see attachment.This applies to the 24FJ128GB210 need to verify this for the PIC32MX795F512L.

author: diyaudio
author_rank: Frequent Contributor
timestamp: February 23, 2014, 06:13:36 pm
content: Okay it successfully read the device after supplying power to the AVdd PIN.thanks @danny motivated to read the power section it was described in bold clearly.

author: Lunasix
author_rank: Regular Contributor
timestamp: February 25, 2014, 11:04:25 am
content: Too late ! Reading the beginning of this post, I was thinking at AVdd. I have had the problem an a board due to a capacitor soldered in place of a resistor in this AVdd line.