Recent content by rogerjef

Pullups on chip select lines only. Pull down on SCLK. The whole of the digital section runs from 3V3. There is +/-5V supplies for the analogy bits. There are no DNC connections on the SOIC8 version of the M25P16. Just M0 failing is the confusing bit.

As I said, Gents. Straw clutching at it's peak. I guess I will now have to wait until the next occurance. Thanks for your suggestions Roger

The RS232 serial lead, used for powering the board during programming, is approx. 2m long, as is the lead to the Real Ice programmer. The lead from the programmer to the header is approx 400mm. The serial lead is always plugged in first. One interesting thing is that the SCLK pull down...

Hi Guys May, repeat, may have found problem. The 0v return on the programmer/board lead was intermittant at the programmer end. Resistance varying from 5 to 76R. New cable 0,5R. Only time will tell. Thanks for all you help Roger

SCLK is shared by the four M25s and an ADC. Unfortunately parts removed were dumped, so no postmortem. We have tried repeatedly programming the processor, some 50 times, whilst monitoring the SCLK line with a digital scope set to trigger at 4V. Nothing failed. A number of boards have been...

I am not sure if the parts were tango-uniform, but I am sure that they were bravo-uniform-golf-golf-echo-romeo-echo-delta. I am the only person programming the development kit, programming could be several times in a day, and then not for weeks. Typical of any design development. The time of...

About 45mm. I agree that it is an electrical issue of significant proportion. But, why only when programming, and possibly only after 40(ish) code loads. Why only M0, when there are 3 other devices connected to the SPI? One of my posts wondered if there was some sort of bleed through when the...

Yes. I assumed that something was happening on the SCLK line, and I was monitoring that line as I was programming. Nothing showed.

Yes, I agree that the input is blown. I don't understand how, or why. It only happens during a programming operation. The board has been programmed probably 70-80 times, and I have had to change the M25 twice, and with several months between changes. I removed the board from the test rig...

During programming, the board is powered via a serial link, RS232, and programmed by the use of a Microchip Real Ice programmer. Both are plugged into a lapdog. I know it is an input, but SCLK has been seen stuck high or low. One of the first things that the code does, after setting ports etc...

IRstuff, It was not possible to test the chip, as it seems that the SCLK was stuck

No the rig is earthed, the point I was making was that any personal charge would be shared with the capacitance of the rig, which is considerable. There was one instance of failure when a board was on an antistatic mat on a bench. All static precautions were observed. Once again the processor...

Not that easy. The aluminium chassis is approx 950mm long by 50mm dia. There is a fairly substantial BLDC motor on one end. The chassis sits on an alloy frame which is approx 1400mm long. The whole of the test rig, that the chassis is attached to, is non-magnetic. It is not possible to...

Thanks for the thought. The test rig comprises of a production chassis, (of what is essentially an inertial platform), and a stand that just varies the inclination and azimuth of the chassis. The processor, during programming, is powered from a lapdog which also drives the Microchip Real Ice...

The monitoring of the M25P16 was done using a digital scope, and refered to a known good ground. The maximum -ve swing on any pin was 250mV. The whole processory bit is running from 3V3.During reloading code none of the M25 pins exceeded 3V6. The operating code is stored exclusively in the...