Reset problem

[Acetronics2]

Hi, Leonel

One simple solution is to bring the 5 v to the PIC ( only the PIC ...) through a diode ( Low drop Schottky if required ) and havind a BIG capacitor ( say 470 - 1000µF ) connected to the Cathode. This doesn't keep you from having the usual 10µF and .1µF decoupling caps.

This will filter spikes, and allow powering the PIC if supply voltage falls too low.

This also permits to shut down all peripheral components BEFORE the Pic goes to bed ... always having known peripheral states at power off.

Alain

Hi, Mel

When you design an Electronic Ignition or a High Voltage device from a battery , you DO NOT have the choice for a "nice and clean" supply !!! ...

[Melanie]

I disagree Alain

The electronics that you design-in between the PIC and the incomming Power Source, be it vehicular or Battery sourced always ensures the PICs supply is clean. If it's not, then you have a disaster waiting to happen - the TGV will derail, the Président de la République Française will resign, the Government will fall, the Guilotine will be taken out of storage and sharpened - and it will all be your fault.

[Acetronics2]

the Président de la République Française will resign, the Government will fall, .

Do you REALLY think it would be a disaster ???

It's evident you don't live here !!! And you do not know anything about Jacques ( Old friend of mine ... )

Alain

PS: aboard your car, you take a diesel generator for the electronics to work ??? ...

[Melanie]

Aboard my car I design-in circuitry between the Supply and the PIC so that the PICs supply is clean. I ensure the raw supply tracks and components are away from the clean-side tracks and components. I ensure the PCB is well designed to absorb induced transients harmlessly. I ensure all I/O's (Analogue or Digital) that go off my PCB are filtered accordingly. But, most importantly, I ensure my public liability insurance is paid-up.

Jacques is a Gaullist... it is well known they prefer Atmel...

I didn't really want to mention it but... recent Reuters photograph shows rioting in Paris street after PIC controlled model airplane slams into street toilet on Rue de Sevres... Journal Le Monde quotes "the devastating methane explosion scattered toilet paper across a wide area and flash-backed down the sewers starting fires in several city suburbs"... see... it's all caused by bad PSU design.

[Acetronics2]

Jacques is a Gaullist...

> Sorry ... he's just an opportunist ... in 68' De Gaulle had called the army tanks ( to be precise they were waiting in Rambouillet ... 50 kms from Paris ) ; here, for the CPE Jacques just lost his pair of trousers ...

Always remember being Gaullist means being a real man ...

it is well known they prefer Atmel ... ( ?????? )

I didn't really want to mention it but... recent Reuters photograph shows rioting in Paris street after PIC controlled model airplane slams into street toilet on Rue de Sevres... Journal Le Monde quotes "the devastating methane explosion scattered toilet paper across a wide area and flash-backed down the sewers starting fires in several city suburbs"... see... it's all caused by bad PSU design.

I'd rather think "THE" model airplane was slammed down due to a huge methane release into the street toilets.

Those toilets vents surely could not bear the induced internal overpressure.

But I know you're joking : Have you ever seen any toilet paper available in our country street toilets ???

Us, We do not have the "Times" to read ...

Cheers

Alain

[mister_e]

Have you ever seen any toilet paper available in our country street toilets ???

mmm as Colonel Harland Sanders (KFC) said... "Finger licking good!"

I wasn't aware that you have any toilet in France anyway

[sayzer]

I wasn't aware that you have any toilet in France anyway

Steve,

We should be thankful to France having no toilet anyway (if that is true of course).

The best perfumes were invented in France and today's best perfume brands come from there, remember?

[sayzer]

Here is an experience for free.

- Seven 24V/1A motors are connected to power supply along with PIC.
- PIC drives tiny relays directly, pulls 23mA, and tiny relays drive 24V relays for motor loads.
- "Sometimes", PIC resets, but not due to the drop in supply voltage. Pls see below.

1. I used separate power supply for PIC. = No change.
2. I used battery only for PIC. = No change
3. I used BOD_ON and OFF and got crazy around its configs. = No change
4. I used forum search, online search, data sheets, the other ones, all the other other ones, and yes those too. = no change
5. Finally, I used a trimpot on MCLR pin, as mentioned above, and fixed the problem adjusting it.
6. No more reset.

Even though once there was no connection between PIC circuit and motors (separate power supply), I still had reset issue.

Now, motors and PIC (BOD_ON) are on the same power supply, no reset occurs.

Meanwhile, BOD_OFF creates LCD problems while it is not supposed to.